Version Packages (#3651)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

.github/CODEOWNERS

@@ -0,0 +1,3 @@
+# Changes to the API data cache functions can invalidate all existing data cache
+# causing a massive amount of revalidation, impacting our API.
+packages/gitbook/src/lib/data/api.ts   @SamyPesse

.github/CONTRIBUTING.md

@@ -53,19 +53,42 @@ After forking this repository, you'll want to [create a branch](https://docs.git
 
 #### 3. Install dependencies and run the project locally
 
-GitBook uses [Bun](https://bun.sh/) to run the project. Make sure you're using the specified version of `node` before running any of the development commands to ensure a smooth development experience.
+##### Prerequisites:
+- Node.js (Version: >=20.6)
+  - Use `nvm` for easy Node management
+- [Bun](https://bun.sh/) (Version: >=1.2.15)
+  - We use a text-based lockfile which isn't supported below 1.2.15
 
-You can easily do this by running the command `nvm use`.
+##### Setup steps:
 
-To start your local version of GitBook, run the command `bun dev`.
+1. Ensure you are using the project's version of Node:
+```bash
+nvm use
+```
+
+2. Install dependencies using Bun:
+```bash
+bun install
+```
+
+3. Start the development server:
+```bash
+bun dev
+```
+
+Additional development commands:
+- `bun format`: Format the code using Biome
+- `bun typecheck`: Run TypeScript type checking
+- `bun unit`: Run unit tests
+- `bun e2e`: Run end-to-end tests
 
 #### 4. Preview your changes
 
-When running the development server, published GitBook sites can be rendered through your local version at `http://localhost:3000/`.
+When running the development server, published GitBook sites can be rendered through your local version at `http://localhost:3000/url`.
 
-For example, our published docs can be viewed using the local version by visiting `http://localhost:3000/docs.gitbook.com` after running the development server.
+For example, our published docs can be viewed using the local version by visiting `http://localhost:3000/url/gitbook.com/docs` after running the development server.
 
-You can visit any published GitBook site behind your development server. Please make sure your site is [published publicly](https://docs.gitbook.com/published-documentation/publish-your-content-as-a-docs-site) to ensure you can view the site correctly in your development version.
+You can visit any published GitBook site behind your development server. Please make sure your site is [published publicly](https://gitbook.com/docs/published-documentation/publish-your-content-as-a-docs-site) to ensure you can view the site correctly in your development version.
 
 ### Commit your update
 

.github/actions/gradual-deploy-cloudflare/action.yaml

@@ -0,0 +1,83 @@
+name: Gradual Deploy to Cloudflare
+description: Use gradual deployment to deploy to Cloudflare. This action will upload the middleware and server versions to Cloudflare and kept them bound together
+inputs:
+  apiToken:
+    description: 'Cloudflare API token'
+    required: true
+  accountId:
+    description: 'Cloudflare account ID'
+    required: true
+  environment:
+    description: 'Cloudflare environment to deploy to (staging, production, preview)'
+    required: true
+  middlewareVersionId:
+    description: 'Middleware version ID to deploy'
+    required: true
+  serverVersionId:
+    description: 'Server version ID to deploy'
+    required: true
+outputs:
+  deployment-url: 
+    description: "Deployment URL"
+    value: ${{ steps.deploy_middleware.outputs.deployment-url }}
+runs:
+  using: 'composite'
+  steps:
+      - id: wrangler_status
+        name: Check wrangler deployment status
+        uses: cloudflare/wrangler-action@v3.14.0
+        with:
+            apiToken: ${{ inputs.apiToken }}
+            accountId: ${{ inputs.accountId }}
+            workingDirectory: ./
+            wranglerVersion: '4.10.0'
+            environment: ${{ inputs.environment }}
+            command: deployments status --config ./packages/gitbook/openNext/customWorkers/defaultWrangler.jsonc
+
+      # This step is used to get the version ID that is currently deployed to Cloudflare.
+      - id: extract_current_version
+        name: Extract current version
+        shell: bash
+        run: |
+          version_id=$(echo "${{ steps.wrangler_status.outputs.command-output }}" | grep -A 3 "(100%)" | grep -oP '[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}')
+          echo "version_id=$version_id" >> $GITHUB_OUTPUT
+
+      - id: deploy_server
+        name: Deploy server to Cloudflare at 0%
+        uses: cloudflare/wrangler-action@v3.14.0
+        with:
+            apiToken: ${{ inputs.apiToken }}
+            accountId: ${{ inputs.accountId }}
+            workingDirectory: ./
+            wranglerVersion: '4.10.0'
+            environment: ${{ inputs.environment }}
+            command: versions deploy ${{ steps.extract_current_version.outputs.version_id }}@100% ${{ inputs.serverVersionId }}@0% -y --config ./packages/gitbook/openNext/customWorkers/defaultWrangler.jsonc
+
+      # Since we use version overrides headers, we can directly deploy the middleware to 100%.
+      - id: deploy_middleware
+        name: Deploy middleware to Cloudflare at 100%
+        uses: cloudflare/wrangler-action@v3.14.0
+        with:
+            apiToken: ${{ inputs.apiToken }}
+            accountId: ${{ inputs.accountId }}
+            workingDirectory: ./
+            wranglerVersion: '4.10.0'
+            environment: ${{ inputs.environment }}
+            command: versions deploy ${{ inputs.middlewareVersionId }}@100% -y --config ./packages/gitbook/openNext/customWorkers/middlewareWrangler.jsonc
+
+      - name: Deploy server to Cloudflare at 100%
+        uses: cloudflare/wrangler-action@v3.14.0
+        with:
+            apiToken: ${{ inputs.apiToken }}
+            accountId: ${{ inputs.accountId }}
+            workingDirectory: ./
+            wranglerVersion: '4.10.0'
+            environment: ${{ inputs.environment }}
+            command: versions deploy ${{ inputs.serverVersionId }}@100% -y --config ./packages/gitbook/openNext/customWorkers/defaultWrangler.jsonc
+
+      - name: Outputs
+        shell: bash
+        env:
+          DEPLOYMENT_URL: ${{ steps.deploy_middleware.outputs.deployment-url }}
+        run: |
+            echo "URL: ${{ steps.deploy_middleware.outputs.deployment-url }}"

.github/actions/setup-playwright/action.yml

@@ -1,37 +0,0 @@
-name: 'Setup Playwright'
-description: 'Install Playwright and dependencies'
-runs:
-    using: 'composite'
-    steps:
-        # Run npm ci and get Playwright version
-        - name: 🏗 Prepare Playwright env
-          shell: bash
-          run: |
-              PLAYWRIGHT_VERSION=$(npm ls --json @playwright/test | jq --raw-output '.dependencies["gitbook"].dependencies["@playwright/test"].version')
-              echo "PLAYWRIGHT_VERSION=$PLAYWRIGHT_VERSION" >> $GITHUB_ENV
-
-        # Cache browser binaries, cache key is based on Playwright version and OS
-        - name: 🧰 Cache Playwright browser binaries
-          uses: actions/cache@v4
-          id: playwright-cache
-          with:
-              path: '~/.cache/ms-playwright'
-              key: '${{ runner.os }}-playwright-${{ env.PLAYWRIGHT_VERSION }}'
-              restore-keys: |
-                  ${{ runner.os }}-playwright-
-
-        # Install browser binaries & OS dependencies if cache missed
-        - name: 🏗 Install Playwright browser binaries & OS dependencies
-          if: steps.playwright-cache.outputs.cache-hit != 'true'
-          shell: bash
-          working-directory: packages/gitbook
-          run: |
-              bun x playwright install --with-deps chromium
-
-        # Install only the OS dependencies if cache hit
-        - name: 🏗 Install Playwright OS dependencies
-          if: steps.playwright-cache.outputs.cache-hit == 'true'
-          shell: bash
-          working-directory: packages/gitbook
-          run: |
-              bun x playwright install-deps

.github/composite/deploy-cloudflare/action.yaml

@@ -28,7 +28,7 @@ inputs:
 outputs:
     deployment-url: 
       description: "Deployment URL"
-      value: ${{ steps.deploy.outputs.deployment-url }}
+      value: ${{ steps.upload_middleware.outputs.deployment-url }}
 runs:
     using: 'composite'
     steps:
@@ -59,12 +59,12 @@ runs:
             GITBOOK_ASSETS_PREFIX: ${{ inputs.opItem }}/GITBOOK_ASSETS_PREFIX
             GITBOOK_FONTS_URL: ${{ inputs.opItem }}/GITBOOK_FONTS_URL
         - name: Build worker
-          run: bun run turbo build:v2:cloudflare
+          run: bun run turbo build:cloudflare
           env:
             GITBOOK_RUNTIME: cloudflare
           shell: bash
-        - id: deploy
+
-          name: Deploy to Cloudflare
+        - name: Upload the DO worker
           uses: cloudflare/wrangler-action@v3.14.0
           with:
               apiToken: ${{ inputs.apiToken }}
@@ -72,10 +72,67 @@ runs:
               workingDirectory: ./
               wranglerVersion: '4.10.0'
               environment: ${{ inputs.environment }}
-              command: ${{ inputs.deploy == 'true' && 'deploy' || format('versions upload --tag {0} --message "{1}"', inputs.commitTag, inputs.commitMessage) }} --config ./packages/gitbook-v2/wrangler.jsonc
+              command: deploy --config ./packages/gitbook/openNext/customWorkers/doWrangler.jsonc
+
+        - id: upload_server
+          name: Upload server to Cloudflare
+          uses: cloudflare/wrangler-action@v3.14.0
+          with:
+              apiToken: ${{ inputs.apiToken }}
+              accountId: ${{ inputs.accountId }}
+              workingDirectory: ./
+              wranglerVersion: '4.10.0'
+              environment: ${{ inputs.environment }}
+              command: ${{ format('versions upload --tag {0} --message "{1}"', inputs.commitTag, inputs.commitMessage) }} --config ./packages/gitbook/openNext/customWorkers/defaultWrangler.jsonc
+
+        - name: Extract server version worker ID
+          shell: bash
+          id: extract_server_version_id
+          run: |
+              version_id=$(echo '${{ steps.upload_server.outputs.command-output }}' | grep "Worker Version ID" | awk '{print $4}')
+              echo "version_id=$version_id" >> $GITHUB_OUTPUT
+
+        - name: Run updateWrangler scripts
+          shell: bash
+          run: |
+              bun run ./packages/gitbook/openNext/customWorkers/script/updateWrangler.ts ${{ steps.extract_server_version_id.outputs.version_id }}
+
+        - id: upload_middleware
+          name: Upload middleware to Cloudflare
+          uses: cloudflare/wrangler-action@v3.14.0
+          with:
+              apiToken: ${{ inputs.apiToken }}
+              accountId: ${{ inputs.accountId }}
+              workingDirectory: ./
+              wranglerVersion: '4.10.0'
+              environment: ${{ inputs.environment }}
+              command: ${{ format('versions upload --tag {0} --message "{1}"', inputs.commitTag, inputs.commitMessage) }} --config ./packages/gitbook/openNext/customWorkers/middlewareWrangler.jsonc
+        
+        - name: Extract middleware version worker ID
+          shell: bash
+          id: extract_middleware_version_id
+          run: |
+              version_id=$(echo '${{ steps.upload_middleware.outputs.command-output }}' | grep "Worker Version ID" | awk '{print $4}')
+              echo "version_id=$version_id" >> $GITHUB_OUTPUT
+
+        - name: Deploy server and middleware to Cloudflare
+          if: ${{ inputs.deploy == 'true' }}
+          uses: ./.github/actions/gradual-deploy-cloudflare
+          with:
+              apiToken: ${{ inputs.apiToken }}
+              accountId: ${{ inputs.accountId }}
+              opServiceAccount: ${{ inputs.opServiceAccount }}
+              opItem: ${{ inputs.opItem }}
+              environment: ${{ inputs.environment }}
+              serverVersionId: ${{ steps.extract_server_version_id.outputs.version_id }}
+              middlewareVersionId: ${{ steps.extract_middleware_version_id.outputs.version_id }}
+              deploy: ${{ inputs.deploy }}
+
+
         - name: Outputs
           shell: bash
           env:
-            DEPLOYMENT_URL: ${{ steps.deploy.outputs.deployment-url }}
+            DEPLOYMENT_URL: ${{ steps.upload_middleware.outputs.deployment-url }}
           run: |
-              echo "URL: ${{ steps.deploy.outputs.deployment-url }}"
+              echo "URL: ${{ steps.upload_middleware.outputs.deployment-url }}"
+              echo "Output server: ${{ steps.upload_server.outputs.command-output }}"

.github/workflows/deploy-preview.yaml

@@ -7,53 +7,6 @@ on:
 env:
     NPM_TOKEN_READONLY: ${{ secrets.NPM_TOKEN_READONLY }}
 jobs:
-    deploy-v1-cloudflare:
-        name: Deploy v1 to Cloudflare Pages
-        runs-on: ubuntu-latest
-        environment:
-          name: ${{ github.ref == 'refs/heads/main' && '1c-production' || '1c-preview' }}
-          url: ${{ steps.deploy.outputs.deployment-url }}
-        permissions:
-            contents: read
-            deployments: write
-            issues: write
-            pull-requests: write
-            checks: write
-            statuses: write
-        outputs:
-            deployment-url: ${{ steps.deploy.outputs.deployment-url }}
-            deployment-alias-url: ${{ steps.deploy.outputs.deployment-alias-url }}
-        steps:
-            - name: Checkout
-              uses: actions/checkout@v4
-            - name: Setup Bun
-              uses: ./.github/composite/setup-bun
-            - name: Install dependencies
-              run: bun install --frozen-lockfile
-              env:
-                  PUPPETEER_SKIP_DOWNLOAD: 1
-            - name: Sets env vars for production
-              if: github.ref == 'refs/heads/main'
-              run: |
-                echo "GITBOOK_ASSETS_PREFIX=https://static.gitbook.com" >> $GITHUB_ENV
-            - name: Build Next.js with next-on-pages
-              run: bun run turbo gitbook#build:cloudflare
-              env:
-                  NEXT_SERVER_ACTIONS_ENCRYPTION_KEY: ${{ secrets.NEXT_SERVER_ACTIONS_ENCRYPTION_KEY }}
-                  GITBOOK_RUNTIME: cloudflare
-            - id: deploy
-              name: Deploy to Cloudflare
-              uses: cloudflare/wrangler-action@v3.14.0
-              with:
-                  apiToken: ${{ secrets.CLOUDFLARE_API_TOKEN }}
-                  accountId: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
-                  workingDirectory: ./
-                  wranglerVersion: '3.112.0'
-                  command: pages deploy ./packages/gitbook/.vercel/output/static --project-name=${{ vars.CLOUDFLARE_PROJECT_NAME }} --branch=${{ github.ref == 'refs/heads/main' && 'main' || format('pr{0}', github.event.pull_request.number) }}
-            - name: Outputs
-              run: |
-                  echo "URL: ${{ steps.deploy.outputs.deployment-url }}"
-                  echo "Alias URL: ${{ steps.deploy.outputs.deployment-alias-url }}"
     deploy-v2-vercel:
         name: Deploy v2 to Vercel (preview)
         runs-on: ubuntu-latest
@@ -114,7 +67,6 @@ jobs:
         name: Comment Deployments (preview)
         if: always() && !startsWith(github.ref, 'refs/heads/main')
         needs:
-            - deploy-v1-cloudflare
             - deploy-v2-vercel
             - deploy-v2-cloudflare
         steps:
@@ -134,15 +86,6 @@ jobs:
                   body: |
                       Summary of the deployments:
 
-                      ### Version 1
-
-                      | Version | URL | Status |
-                      | --- | --- | --- |
-                      | Latest commit | [${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}](${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}) | ${{ needs.deploy-v1-cloudflare.result == 'success' && '✅' || '❌' }} |
-                      | PR | [${{ needs.deploy-v1-cloudflare.outputs.deployment-alias-url }}](${{ needs.deploy-v1-cloudflare.outputs.deployment-alias-url }}) | ${{ needs.deploy-v1-cloudflare.result == 'success' && '✅' || '❌' }} |
-
-                      ### Version 2
-
                       | Version | URL | Status |
                       | --- | --- | --- |
                       | Vercel | [${{ needs.deploy-v2-vercel.outputs.deployment-url }}](${{ needs.deploy-v2-vercel.outputs.deployment-url }}) | ${{ needs.deploy-v2-vercel.result == 'success' && '✅' || '❌' }} |
@@ -150,35 +93,16 @@ jobs:
 
                       ### Test content
 
-                      | Site | `v1` | `2v` | `2c` |
+                      | Site | `2v` | `2c` |
-                      | --- | --- | --- | --- |
+                      | --- | --- | --- |
-                      | GitBook | [${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}/docs.gitbook.com](${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}/docs.gitbook.com) | [${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/docs.gitbook.com](${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/docs.gitbook.com) | [${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/docs.gitbook.com](${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/docs.gitbook.com) |
+                      | GitBook | [${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/gitbook.com/docs](${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/gitbook.com/docs) | [${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/gitbook.com/docs](${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/gitbook.com/docs) |
-                      | E2E | [${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}/gitbook.gitbook.io/test-gitbook-open](${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}/gitbook.gitbook.io/test-gitbook-open) | [${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open](${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open) | [${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open](${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open) |
+                      | E2E | [${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open](${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open) | [${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open](${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/gitbook.gitbook.io/test-gitbook-open) |
                   edit-mode: replace
-    visual-testing-v1:
-        runs-on: ubuntu-latest
-        name: Visual Testing v1
-        needs: deploy-v1-cloudflare
-        timeout-minutes: 8
-        steps:
-            - name: Checkout
-              uses: actions/checkout@v4
-            - name: Setup Bun
-              uses: ./.github/composite/setup-bun
-            - name: Install dependencies
-              run: bun install --frozen-lockfile
-            - name: Setup Playwright
-              uses: ./.github/actions/setup-playwright
-            - name: Run Playwright tests
-              run: bun e2e
-              env:
-                  BASE_URL: ${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}
-                  ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
     visual-testing-v2-vercel:
         runs-on: ubuntu-latest
         name: Visual Testing v2
         needs: deploy-v2-vercel
-        timeout-minutes: 10
+        timeout-minutes: 15
         steps:
             - name: Checkout
               uses: actions/checkout@v4
@@ -186,8 +110,8 @@ jobs:
               uses: ./.github/composite/setup-bun
             - name: Install dependencies
               run: bun install --frozen-lockfile
-            - name: Setup Playwright
+              env:
-              uses: ./.github/actions/setup-playwright
+                  PUPPETEER_SKIP_DOWNLOAD: 1
             - name: Run Playwright tests
               run: bun e2e
               env:
@@ -199,8 +123,7 @@ jobs:
         runs-on: ubuntu-latest
         name: Visual Testing v2 (Cloudflare)
         needs: deploy-v2-cloudflare
-        timeout-minutes: 10
+        timeout-minutes: 15
-        if: startsWith(github.head_ref || github.ref_name, 'cloudflare/') || github.ref == 'refs/heads/main'
         steps:
             - name: Checkout
               uses: actions/checkout@v4
@@ -208,8 +131,8 @@ jobs:
               uses: ./.github/composite/setup-bun
             - name: Install dependencies
               run: bun install --frozen-lockfile
-            - name: Setup Playwright
+              env:
-              uses: ./.github/actions/setup-playwright
+                  PUPPETEER_SKIP_DOWNLOAD: 1
             - name: Run Playwright tests
               run: bun e2e
               env:
@@ -217,31 +140,11 @@ jobs:
                   SITE_BASE_URL: ${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/
                   ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
                   ARGOS_BUILD_NAME: 'v2-cloudflare'
-    visual-testing-customers-v1:
-        runs-on: ubuntu-latest
-        name: Visual Testing Customers v1
-        needs: deploy-v1-cloudflare
-        timeout-minutes: 8
-        steps:
-            - name: Checkout
-              uses: actions/checkout@v4
-            - name: Setup Bun
-              uses: ./.github/composite/setup-bun
-            - name: Install dependencies
-              run: bun install --frozen-lockfile
-            - name: Setup Playwright
-              uses: ./.github/actions/setup-playwright
-            - name: Run Playwright tests
-              run: bun e2e-customers
-              env:
-                  BASE_URL: ${{ needs.deploy-v1-cloudflare.outputs.deployment-url }}
-                  ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
-                  ARGOS_BUILD_NAME: 'customers-v1'
     visual-testing-customers-v2:
         runs-on: ubuntu-latest
         name: Visual Testing Customers v2
         needs: deploy-v2-vercel
-        timeout-minutes: 8
+        timeout-minutes: 15
         steps:
             - name: Checkout
               uses: actions/checkout@v4
@@ -249,8 +152,8 @@ jobs:
               uses: ./.github/composite/setup-bun
             - name: Install dependencies
               run: bun install --frozen-lockfile
-            - name: Setup Playwright
+              env:
-              uses: ./.github/actions/setup-playwright
+                  PUPPETEER_SKIP_DOWNLOAD: 1
             - name: Run Playwright tests
               run: bun e2e-customers
               env:
@@ -262,28 +165,7 @@ jobs:
         runs-on: ubuntu-latest
         name: Visual Testing Customers v2 (Cloudflare)
         needs: deploy-v2-cloudflare
-        timeout-minutes: 8
+        timeout-minutes: 15
-        if: startsWith(github.head_ref || github.ref_name, 'cloudflare/') || github.ref == 'refs/heads/main'
-        steps:
-            - name: Checkout
-              uses: actions/checkout@v4
-            - name: Setup Bun
-              uses: ./.github/composite/setup-bun
-            - name: Install dependencies
-              run: bun install --frozen-lockfile
-            - name: Setup Playwright
-              uses: ./.github/actions/setup-playwright
-            - name: Run Playwright tests
-              run: bun e2e-customers
-              env:
-                  BASE_URL: ${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}
-                  SITE_BASE_URL: ${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/
-                  ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
-                  ARGOS_BUILD_NAME: 'customers-v2'
-    pagespeed-testing-v1:
-        runs-on: ubuntu-latest
-        name: PageSpeed Testing v1
-        needs: deploy-v1-cloudflare
         steps:
             - name: Checkout
               uses: actions/checkout@v4
@@ -293,8 +175,46 @@ jobs:
               run: bun install --frozen-lockfile
               env:
                   PUPPETEER_SKIP_DOWNLOAD: 1
-            - name: Run pagespeed tests
+            - name: Run Playwright tests
-              run: bun ./packages/gitbook/tests/pagespeed-testing.ts
+              run: bun e2e-customers
               env:
-                  BASE_URL: ${{needs.deploy-v1-cloudflare.outputs.deployment-url}}
+                  BASE_URL: ${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}
-                  PAGESPEED_API_KEY: ${{ secrets.PAGESPEED_API_KEY }}
+                  SITE_BASE_URL: ${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/
+                  ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
+                  ARGOS_BUILD_NAME: 'customers-v2'
+    browserless-testing-v2-vercel:
+        runs-on: ubuntu-latest
+        name: Browserless Testing v2 (Vercel)
+        needs: deploy-v2-vercel
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v4
+            - name: Setup Bun
+              uses: ./.github/composite/setup-bun
+            - name: Install dependencies
+              run: bun install --frozen-lockfile
+              env:
+                  PUPPETEER_SKIP_DOWNLOAD: 1
+            - name: Run tests
+              run: cd ./packages/gitbook && bun e2e-browserless
+              env:
+                  BASE_URL: ${{needs.deploy-v2-vercel.outputs.deployment-url}}
+                  SITE_BASE_URL: ${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/
+    # browserless-testing-v2-cloudflare:
+    #     runs-on: ubuntu-latest
+    #     name: Browserless Testing v2 (Cloudflare)
+    #     needs: deploy-v2-cloudflare
+    #     steps:
+    #         - name: Checkout
+    #           uses: actions/checkout@v4
+    #         - name: Setup Bun
+    #           uses: ./.github/composite/setup-bun
+    #         - name: Install dependencies
+    #           run: bun install --frozen-lockfile
+    #           env:
+    #               PUPPETEER_SKIP_DOWNLOAD: 1
+    #         - name: Run tests
+    #           run: cd ./packages/gitbook && bun e2e-browserless
+    #           env:
+    #               BASE_URL: ${{needs.deploy-v2-cloudflare.outputs.deployment-url}}
+    #               SITE_BASE_URL: ${{ needs.deploy-v2-cloudflare.outputs.deployment-url }}/url/

.github/workflows/publish.yaml

@@ -39,22 +39,4 @@ jobs:
                   NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
                   CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
                   CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
-    release-preview:
+
-        # For now it releases the cache-do to both preview and production
-        # Once we changed to deploy the app only on release, we should change `release:preview` in `cache-do`
-        name: Release Preview
-        runs-on: ubuntu-latest
-        steps:
-            - name: Checkout Repo
-              uses: actions/checkout@v3
-            - name: Setup Bun
-              uses: ./.github/composite/setup-bun
-            - name: Install dependencies
-              run: bun install --frozen-lockfile
-              env:
-                  PUPPETEER_SKIP_DOWNLOAD: 1
-            - name: Release preview packages
-              run: bun run release:preview
-              env:
-                  CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
-                  CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}

.vscode/settings.json

@@ -9,6 +9,7 @@
     ],
     "tailwindCSS.classAttributes": ["class", "className", "style", ".*Style"],
     "prettier.enable": false,
+    "editor.formatOnSave": true,
     "editor.defaultFormatter": "biomejs.biome",
     "editor.codeActionsOnSave": {
         "source.organizeImports.biome": "explicit",

README.md

@@ -1,7 +1,7 @@
 <h1 align="center">GitBook</h1>
 
 <p align="center">
-  <a href="https://docs.gitbook.com/">Docs</a> - <a href="https://github.com/GitbookIO/community">Community</a> - <a href="https://developer.gitbook.com/">Developer Docs</a> - <a href="https://changelog.gitbook.com/">Changelog</a> - <a href="https://github.com/GitbookIO/gitbook/issues/new?assignees=&labels=bug&template=bug_report.md">Bug reports</a> 
+  <a href="https://gitbook.com/docs/">Docs</a> - <a href="https://github.com/GitbookIO/community">Community</a> - <a href="https://developer.gitbook.com/">Developer Docs</a> - <a href="https://changelog.gitbook.com/">Changelog</a> - <a href="https://github.com/GitbookIO/gitbook/issues/new?assignees=&labels=bug&template=bug_report.md">Bug reports</a> - <a href="https://github.com/orgs/GitbookIO/discussions/categories/feature-requests">Feature requests</a> 
 </p>
 
 <p align="center">
@@ -35,10 +35,10 @@ To run a local version of this project, please follow these simple steps.
 
 ### Prerequisites
 
--   Node.js (Version: >=20.6)
+- Node.js (Version: >=20.6)
-  - Use nvm for easy Node management
+    - Use nvm for easy Node management
--   Bun (Version: >=1.2.1)
+- [Bun](https://bun.sh/) (Version: >=1.2.15)
-  - We use a text-based lockfile which isn't supported below 1.2.1
+  - We use a text-based lockfile which isn't supported below 1.2.15
 
 ### Set up
 
@@ -59,23 +59,18 @@ bun install
 4. Start your local development server.
 
 ```
-bun dev:v2
+bun dev
 ```
 
-5. Open a published GitBook space in your web browser, prefixing it with `http://localhost:3000/`.
+6. Open a published GitBook space in your web browser, prefixing it with `http://localhost:3000/url`.
 
 examples:
 
--   http://localhost:3000/url/docs.gitbook.com
+-   http://localhost:3000/url/gitbook.com/docs
 -   http://localhost:3000/url/open-source.gitbook.io/midjourney
 
 Any published GitBook site can be accessed through your local development instance, and any updates you make to the codebase will be reflected in your browser.
 
-### Other development commands
-
--   `bun format`: format the code
--   `bun lint`: lint the code
-
 ### CI and testing
 
 All pull-requests will be tested against both visual and performances testing to prevent regressions.
@@ -150,11 +145,11 @@ See `LICENSE` for more information.
 </p>
 
 ```md
-[![GitBook](https://img.shields.io/static/v1?message=Documented%20on%20GitBook&logo=gitbook&logoColor=ffffff&label=%20&labelColor=5c5c5c&color=3F89A1)](https://gitbook.com/)
+[![GitBook](https://img.shields.io/static/v1?message=Documented%20on%20GitBook&logo=gitbook&logoColor=ffffff&label=%20&labelColor=5c5c5c&color=3F89A1)](https://www.gitbook.com/preview?utm_source=gitbook_readme_badge&utm_medium=organic&utm_campaign=preview_documentation&utm_content=link)
 ```
 
 ```html
-<a href="https://gitbook.com">
+<a href="https://www.gitbook.com/preview?utm_source=gitbook_readme_badge&utm_medium=organic&utm_campaign=preview_documentation&utm_content=link">
     <img
         src="https://img.shields.io/static/v1?message=Documented%20on%20GitBook&logo=gitbook&logoColor=ffffff&label=%20&labelColor=5c5c5c&color=3F89A1"
     />

biome.json

@@ -18,10 +18,12 @@
             "**/.vercel/**/*",
             "**/.cache/**/*",
             "**/.wrangler/**/*",
+            "packages/embed/standalone/**/*",
             "packages/openapi-parser/src/fixtures/**/*",
             "packages/emoji-codepoints/index.ts",
             "packages/icons/src/data/*.json",
-            "packages/cache-do/worker-configuration.d.ts"
+            "packages/gitbook/worker-configuration.d.ts",
+            "**/*.css"
         ]
     },
     "formatter": {
@@ -127,7 +129,6 @@
         {
             "include": [
                 "packages/gitbook/**/*",
-                "packages/gitbook-v2/**/*",
                 "packages/react-openapi/**/*",
                 "packages/react-math/**/*",
                 "packages/react-contentkit/**/*",

package.json

@@ -3,23 +3,21 @@
     "version": "0.1.0",
     "devDependencies": {
         "@biomejs/biome": "^1.9.4",
-        "@changesets/cli": "^2.27.12",
+        "@changesets/cli": "^2.29.7",
-        "turbo": "^2.5.0",
+        "turbo": "^2.5.8",
-        "vercel": "^39.3.0"
+        "vercel": "^39.4.2"
     },
-    "packageManager": "bun@1.2.8",
+    "packageManager": "bun@1.2.15",
     "overrides": {
         "@codemirror/state": "6.4.1",
-        "react": "18.3.1",
+        "react": "^19.0.0",
-        "react-dom": "18.3.1",
+        "react-dom": "^19.0.0",
-        "@gitbook/api": "0.111.0"
+        "esbuild": "0.24.2"
     },
     "private": true,
     "scripts": {
-        "dev": "turbo run dev",
+        "dev": "turbo run dev --concurrency 20",
-        "dev:v2": "turbo run dev:v2",
         "build": "turbo run build",
-        "build:v2": "turbo run build:v2",
         "clean-deps": "rm -rf node_modules && rm -rf packages/*/node_modules",
         "typecheck": "turbo run typecheck",
         "format": "biome check --write ./",
@@ -28,13 +26,20 @@
         "e2e": "turbo run e2e",
         "e2e-customers": "turbo run e2e-customers",
         "changeset": "changeset",
-        "changeset-version": "changeset version && bun run format",
+        "changeset-version": "changeset version && bun run format && bun update",
-        "release": "turbo run release && changeset publish",
+        "release": "turbo run release && bun run publish-all-packages",
-        "release:preview": "turbo run release:preview",
+        "publish-all-packages": "for dir in packages/*; do (cd \"$dir\" && bun publish || true); done && changeset tag",
         "download:env": "op read op://gitbook-x-dev/gitbook-open/.env.local >> .env.local",
         "clean": "turbo run clean"
     },
-    "workspaces": ["packages/*"],
+    "workspaces": {
+        "packages": ["packages/*"],
+        "catalog": {
+            "@gitbook/api": "0.143.2",
+            "bidc": "^0.0.2",
+            "tsdown": "^0.15.6"
+        }
+    },
     "patchedDependencies": {
         "decode-named-character-reference@1.0.2": "patches/decode-named-character-reference@1.0.2.patch",
         "@vercel/next@4.4.2": "patches/@vercel%2Fnext@4.4.2.patch"

packages/browser-types/.gitignore

@@ -0,0 +1 @@
+dist/

packages/browser-types/CHANGELOG.md

@@ -0,0 +1,13 @@
+# @gitbook/browser-types
+
+## 0.1.0
+
+### Minor Changes
+
+- cbc71a5: First version of the public package for typing script integrations.
+
+### Patch Changes
+
+- 854c448: Custom assistants followup
+- Updated dependencies [25e2b40]
+  - @gitbook/icons@0.3.0

packages/browser-types/README.md

@@ -0,0 +1,3 @@
+# `@gitbook/browser-types`
+
+Typescript types for the global variables available in a GitBook website. These types can be used by integrations embedding scripts.

packages/browser-types/package.json

@@ -0,0 +1,24 @@
+{
+    "name": "@gitbook/browser-types",
+    "description": "Typescript types for the global variables available in a GitBook website. These types can be used by integrations embedding scripts.",
+    "type": "module",
+    "exports": {
+        ".": {
+            "types": "./dist/index.d.ts",
+            "default": "./dist/index.js"
+        }
+    },
+    "version": "0.1.0",
+    "dependencies": {
+        "@gitbook/api": "catalog:",
+        "@gitbook/icons": "workspace:"
+    },
+    "devDependencies": {
+        "typescript": "^5.5.3"
+    },
+    "scripts": {
+        "build": "tsc",
+        "typecheck": "tsc --noEmit"
+    },
+    "files": ["dist", "README.md", "CHANGELOG.md"]
+}

packages/browser-types/src/index.ts

@@ -0,0 +1,84 @@
+import type { AIToolCallResult, AIToolDefinition } from '@gitbook/api';
+import type { IconName } from '@gitbook/icons';
+
+export type GitBookIntegrationEvent = 'load' | 'unload';
+
+export type GitBookIntegrationEventCallback = (...args: any[]) => void;
+
+export type GitBookIntegrationTool = AIToolDefinition & {
+    /**
+     * Confirmation action to be displayed to the user before executing the tool.
+     */
+    confirmation?: {
+        icon?: IconName;
+        label: string;
+    };
+
+    /**
+     * Callback when the tool is executed.
+     * The input is provided by the AI assistant following the input schema of the tool.
+     */
+    execute: (input: object) => Promise<Pick<AIToolCallResult, 'output' | 'summary'>>;
+};
+
+export type GitBookAssistant = {
+    /**
+     * Name of the assistant displayed in the UI.
+     */
+    label: string;
+
+    /**
+     * Icon of the assistant displayed in the UI.
+     * Any FontAwesome icon name is supported.
+     * @example 'sparkle'
+     */
+    icon: string;
+
+    /**
+     * Callback when the assistant is opened.
+     */
+    open: (query?: string) => void;
+
+    /**
+     * Whether to display the triggers for this assistant in the UI.
+     * @default true
+     */
+    ui?: boolean;
+};
+
+export type GitBookGlobal = {
+    /**
+     * Register an event listener.
+     */
+    addEventListener: (
+        type: GitBookIntegrationEvent,
+        func: GitBookIntegrationEventCallback
+    ) => void;
+
+    /**
+     * Remove an event listener.
+     */
+    removeEventListener: (
+        type: GitBookIntegrationEvent,
+        func: GitBookIntegrationEventCallback
+    ) => void;
+
+    /**
+     * Register a custom tool to be exposed to the AI assistant.
+     */
+    registerTool: (tool: GitBookIntegrationTool) => void;
+
+    /**
+     * Register a custom assistant to be available on the site.
+     */
+    registerAssistant: (assistant: GitBookAssistant) => () => void;
+};
+
+declare global {
+    interface Window {
+        /**
+         * Global `window.GitBook` object accessible by integrations.
+         */
+        GitBook?: GitBookGlobal;
+    }
+}

packages/browser-types/tsconfig.json

@@ -0,0 +1,25 @@
+{
+    "compilerOptions": {
+        "target": "esnext",
+        "lib": ["dom", "dom.iterable", "esnext"],
+        "allowJs": true,
+        "skipLibCheck": true,
+        "strict": true,
+        "noUncheckedIndexedAccess": true,
+        "noEmit": false,
+        "declaration": true,
+        "outDir": "dist",
+        "esModuleInterop": true,
+        "module": "esnext",
+        "moduleResolution": "bundler",
+        "resolveJsonModule": true,
+        "isolatedModules": true,
+        "jsx": "react-jsx",
+        "incremental": true,
+        "types": [
+            "bun-types" // add Bun global
+        ]
+    },
+    "include": ["src/**/*.ts", "src/**/*.tsx"],
+    "exclude": ["node_modules"]
+}

packages/cache-do/.gitignore

@@ -1,3 +0,0 @@
-.wrangler
-worker-configuration.d.ts
-dist/

packages/cache-do/CHANGELOG.md

@@ -1,18 +0,0 @@
-# @gitbook/cache-do
-
-## 0.1.1
-
-### Patch Changes
-
--   b7a5106: Disable cloudflare observability in production
-
-## 0.1.0
-
-### Minor Changes
-
--   9b8d519: Experiment with optimizing billable duration in Cloudflare by using multiple RPC sessions instead of one
--   636b868: First version of a new cache backend powered by Cloudflare Durable Objects
-
-### Patch Changes
-
--   56f5fa1: Enable Workers observability with a sampling of 0.1

packages/cache-do/README.md

@@ -1,22 +0,0 @@
-# `@gitbook/cache-do`
-
-Cache backend, powered by Cloudflare Durable Objects. The cache is optimized for GitBook use-cases.
-
-### Performances
-
-The cache backend is optimized for performances by being distributed and accessible close to the worker locations that are reading it.
-
-### Geo-distribution
-
-To achieve a good balance between **performances** and **consistency**, cache objects are distributed over 7 locations, representing continents.
-
-It makes it possible to purge all 7 locations in one go and achieve fast consistency.
-
-### Concepts
-
-**Cache tag**: unique tag in the cache environment. A cache tag groups multiple keys that should be purged together in one operation.
-Cache tags should not contain a large set of unique keys. Exceeding thousands could lead to performances or reliability issues.
-
-**Cache key**: unique key in the cache environment. Each key should be assigned to a `tag`.
-
-**Location**: cache is distributed over 7 unique locations, one for each continent.

packages/cache-do/package.json

@@ -1,35 +0,0 @@
-{
-    "name": "@gitbook/cache-do",
-    "type": "module",
-    "private": true,
-    "exports": {
-        ".": {
-            "types": "./dist/index.d.ts",
-            "development": "./src/index.ts",
-            "default": "./dist/index.js"
-        },
-        "./api": {
-            "types": "./dist/api.d.ts",
-            "development": "./src/api.ts",
-            "default": "./dist/api.js"
-        }
-    },
-    "version": "0.1.1",
-    "dependencies": {
-        "@msgpack/msgpack": "^3.0.0-beta2",
-        "lru_map": "^0.4.1"
-    },
-    "devDependencies": {
-        "typescript": "^5.5.3",
-        "wrangler": "^4.10.0"
-    },
-    "scripts": {
-        "generate": "wrangler types",
-        "build": "tsc",
-        "typecheck": "tsc --noEmit",
-        "dev": "tsc -w",
-        "release": "wrangler deploy",
-        "release:preview": "wrangler deploy && wrangler deploy --env preview"
-    },
-    "files": ["dist", "src", "bin", "data", "README.md", "CHANGELOG.md"]
-}

packages/cache-do/src/CacheObject.ts

@@ -1,292 +0,0 @@
-import { DurableObject } from 'cloudflare:workers';
-import { decode, encode } from '@msgpack/msgpack';
-import { LRUMap } from 'lru_map';
-
-export interface CacheObjectDescriptor {
-    get: <Value = unknown>(key: string) => Promise<Value | undefined>;
-    set: <Value = unknown>(key: string, value: Value, expiresAt: number) => Promise<void>;
-}
-
-/**
- * Value stored in a chunked binary msgpack format.
- * Stored under the key `prop.${key}.${index}`.
- */
-interface CacheObjectProp<Value = unknown> {
-    value: Value;
-    expiresAt: number;
-}
-
-/**
- * Expiration clock stored under the key `exp.${expiresAt}.${key}`.
- */
-interface CacheObjectExp {
-    /** Key of the property */
-    k: string;
-    /** Number of chunks */
-    c: number;
-}
-
-/**
- * Durable Object class being deployed as a distributed cache.
- */
-export class CacheObject extends DurableObject {
-    private lru = new LRUMap<string, { match: CacheObjectProp | undefined }>(500);
-
-    /**
-     * Open a descriptor to access the cache object.
-     * The goal is to minimize the amount of RPC sessions between the client and the cache object.
-     * One session is opened per request on the client side and used to perform multiple operations.
-     * https://developers.cloudflare.com/workers/runtime-apis/rpc/#return-functions-from-rpc-methods
-     */
-    public open(): CacheObjectDescriptor {
-        return {
-            get: async <Value = unknown>(key: string) => {
-                return this.get<Value>(key);
-            },
-            set: async <Value = unknown>(key: string, value: Value, expiresAt: number) => {
-                await this.set(key, value, expiresAt);
-            },
-        };
-    }
-
-    /**
-     * Get the value of a property.
-     */
-    public async get<Value = unknown>(key: string) {
-        return this.logOperation({ operation: 'get', key }, async (setLog) => {
-            // Try the memory state first.
-            const memoryEntry = this.lru.get(key);
-            if (memoryEntry) {
-                setLog({ memory: true });
-                setLog({ memoryMatch: !!memoryEntry.match });
-                if (!memoryEntry.match) {
-                    return;
-                }
-
-                const isExpired = memoryEntry.match.expiresAt < Date.now();
-                setLog({ memoryExpired: isExpired });
-
-                if (!isExpired) {
-                    return memoryEntry.match.value as Value;
-                }
-            }
-
-            return await this.getFromStorage<Value>(key);
-        });
-    }
-
-    /**
-     * Get the value of a property from the DO storage.
-     */
-    public async getFromStorage<Value = unknown>(key: string) {
-        return this.logOperation({ operation: 'getFromStorage', key }, async (setLog) => {
-            const entries = await this.ctx.storage.list<Uint8Array>({
-                prefix: getStoragePropKey(key),
-                noCache: true,
-            });
-            if (entries.size) {
-                const entry = decodeChunks<CacheObjectProp<Value>>(entries);
-                setLog({ chunks: entries.size, chunksSize: entry?.size ?? 0 });
-                if (entry && entry.value.expiresAt > Date.now()) {
-                    // Found
-                    this.lru.set(key, { match: entry.value });
-                    return entry.value.value;
-                }
-            }
-
-            // Not found
-            this.lru.set(key, { match: undefined });
-        });
-    }
-
-    /**
-     * Set a value in the cache object.
-     */
-    public async set<Value = unknown>(key: string, value: Value, expiresAt: number) {
-        return this.logOperation({ operation: 'set', key }, async (setLog) => {
-            const prop: CacheObjectProp<Value> = {
-                value,
-                expiresAt,
-            };
-
-            this.lru.set(key, { match: prop });
-            await this.ctx.storage.transaction(async (tx) => {
-                const entries = encodeChunks(key, prop);
-                const chunks = Object.keys(entries).length;
-                setLog({ chunks });
-
-                const clockValue: CacheObjectExp = {
-                    k: key,
-                    c: chunks,
-                };
-
-                await tx.put(getGCClockKey(key, expiresAt), clockValue);
-                await tx.put(entries);
-
-                const currentAlarm = await tx.getAlarm();
-                if (!currentAlarm) {
-                    // Set an alarm to garbage collect all entries that have expired in 12h.
-                    await tx.setAlarm(Date.now() + 12 * 60 * 60 * 1000);
-                }
-            });
-        });
-    }
-
-    /**
-     * Purge all keys in the cache object.
-     */
-    public async purge() {
-        return this.logOperation({ operation: 'purge' }, async (setLog) => {
-            const result = new Set<string>();
-
-            try {
-                // List all the keys in the cache object.
-                const entries = await this.ctx.storage.list<CacheObjectExp>({
-                    prefix: 'exp.',
-                    noCache: true,
-                });
-                setLog({ entries: entries.size });
-                entries.forEach((exp) => {
-                    result.add(exp.k);
-                });
-            } catch (_error) {}
-
-            await this.reset();
-            return Array.from(result);
-        });
-    }
-
-    /**
-     * Alarm to garbage collect all entries that have expired.
-     */
-    async alarm() {
-        return this.logOperation({ operation: 'alarm' }, async (setLog) => {
-            try {
-                const entries = await this.ctx.storage.list<CacheObjectExp>({
-                    prefix: 'exp.',
-                    noCache: true,
-                });
-                setLog({ entries: entries.size });
-                const toDeleteSet = new Set<string>();
-
-                for (const [key, exp] of entries) {
-                    const timestamp = Number.parseInt(key.split('.')[1]);
-                    if (timestamp < Date.now()) {
-                        toDeleteSet.add(key);
-                        for (let i = 0; i < exp.c; i++) {
-                            toDeleteSet.add(getStoragePropChunkKey(exp.k, i));
-                        }
-                    }
-                }
-
-                // Delete the keys by batch of 128.
-                const toDelete = Array.from(toDeleteSet);
-                setLog({ toDelete: toDelete.length });
-                for (let i = 0; i < toDelete.length; i += 128) {
-                    await this.ctx.storage.delete(toDelete.slice(i, i + 128));
-                }
-
-                // If there are still keys to delete, set an alarm to continue the deletion in 12h.
-                if (toDelete.length) {
-                    await this.ctx.storage.setAlarm(Date.now() + 12 * 60 * 60 * 1000);
-                }
-            } catch (_error) {
-                await this.reset();
-            }
-        });
-    }
-
-    /**
-     * Reset the cache object.
-     */
-    async reset() {
-        return this.logOperation({ operation: 'reset' }, async () => {
-            this.lru.clear();
-            await this.ctx.storage.deleteAll();
-        });
-    }
-
-    /**
-     * Time and log an operation.
-     */
-    async logOperation<T>(
-        log: Record<string, unknown>,
-        fn: (update: (log: Record<string, unknown>) => void) => Promise<T>
-    ): Promise<T> {
-        const objectId = this.ctx.id.name ?? this.ctx.id.toString();
-        const update: Record<string, unknown> = {};
-        const start = performance.now();
-        try {
-            return await fn((arg) => {
-                Object.assign(update, arg);
-            });
-        } finally {
-            const duration = performance.now() - start;
-            console.log({ ...log, ...update, objectId, duration });
-        }
-    }
-}
-
-function getStoragePropKey(key: string): string {
-    return `prop.${key}.`;
-}
-
-function getStoragePropChunkKey(key: string, index: number): string {
-    return `${getStoragePropKey(key)}${index}`;
-}
-
-function getGCClockRootKey(timestamp: number): string {
-    return `exp.${timestamp}.`;
-}
-
-function getGCClockKey(key: string, expiresAt: number): string {
-    return `${getGCClockRootKey(expiresAt)}${key}`;
-}
-
-function encodeChunks<T>(key: string, value: T): Record<string, Uint8Array> {
-    const buf = encode(value);
-    const entries: Record<string, Uint8Array> = {};
-    const chunks = chunkUint8Array(buf, 128 * 1024);
-
-    for (let index = 0; index < chunks.length; index++) {
-        entries[getStoragePropChunkKey(key, index)] = chunks[index];
-    }
-
-    return entries;
-}
-
-function decodeChunks<T>(entries: Map<string, Uint8Array>): { value: T; size: number } | undefined {
-    const chunks = Array.from(entries.entries())
-        .map(([key, value]) => {
-            const index = Number.parseInt(key.split('.').pop()!);
-            return [index, value] as const;
-        })
-        .sort(([a], [b]) => a - b)
-        .map(([, value]) => value);
-
-    if (chunks.length === 0) {
-        return;
-    }
-
-    const buf = mergeUint8Array(chunks);
-    return { value: decode(buf) as T, size: buf.length };
-}
-
-function chunkUint8Array(input: Uint8Array, chunkSize: number): Uint8Array[] {
-    const chunks: Uint8Array[] = [];
-    for (let i = 0; i < input.length; i += chunkSize) {
-        chunks.push(input.slice(i, i + chunkSize));
-    }
-    return chunks;
-}
-
-function mergeUint8Array(chunks: Uint8Array[]): Uint8Array {
-    const totalLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);
-    const result = new Uint8Array(totalLength);
-    let offset = 0;
-    for (const chunk of chunks) {
-        result.set(chunk, offset);
-        offset += chunk.length;
-    }
-    return result;
-}

packages/cache-do/src/CacheObjectStub.ts

@@ -1,97 +0,0 @@
-import type { CacheObject } from './CacheObject';
-
-export type CacheLocationId = ContinentCode;
-const allLocations: CacheLocationId[] = ['AF', 'AS', 'NA', 'SA', 'AN', 'EU', 'OC'];
-
-/**
- * Location hint for the CacheObject durable object.
- */
-const doLocationHints: {
-    [key in CacheLocationId]: DurableObjectLocationHint;
-} = {
-    AF: 'afr',
-    AS: 'apac',
-    NA: 'wnam',
-    SA: 'sam',
-    AN: 'oc',
-    EU: 'weur',
-    OC: 'oc',
-};
-
-/**
- * Client to access a cache tag.
- */
-export class CacheObjectStub {
-    private stub: DurableObjectStub<CacheObject>;
-
-    constructor(
-        /** Binding to the CacheObject durable object */
-        private doNamespace: DurableObjectNamespace<CacheObject>,
-        /** ID of the location to target */
-        private locationId: CacheLocationId,
-        /** Name of the tag */
-        private tag: string
-    ) {
-        const groupId = getCacheObjectIdName(this.locationId, this.tag);
-        this.stub = this.doNamespace.get(this.doNamespace.idFromName(groupId), {
-            // Initialize the object with a locaiton hint,
-            // as we might want to purge all locations before the object is created.
-            // https://developers.cloudflare.com/durable-objects/reference/data-location/
-            locationHint: doLocationHints[this.locationId],
-        });
-    }
-
-    /**
-     * Open a descriptor to the cache object.
-     * It can be used to perform multiple operations in a single RPC session.
-     * Ex:
-     * ```ts
-     * using desc = cache.open();
-     * await desc.set('key', 'value', Date.now() + 1000);
-     * await desc.get('key');
-     * ```
-     */
-    async open() {
-        return await this.stub.open();
-    }
-
-    /**
-     * Get a value from the cache.
-     */
-    async get<Value = unknown>(key: string) {
-        return (await this.stub.get(key)) as Value | undefined;
-    }
-
-    /**
-     * Set a value in the cache.
-     */
-    async set<Value = unknown>(key: string, value: Value, expiresAt: number) {
-        return await this.stub.set(key, value, expiresAt);
-    }
-
-    /**
-     * Purge all keys in the cache tag.
-     */
-    async purge() {
-        const keys = new Set<string>();
-        await Promise.all(
-            allLocations.map(async (locationId) => {
-                const groupId = getCacheObjectIdName(locationId, this.tag);
-                const cacheGroup = this.doNamespace.get(this.doNamespace.idFromName(groupId), {
-                    // Initialize the object with a locaiton hint,
-                    // as we might want to purge all locations before the object is created.
-                    // https://developers.cloudflare.com/durable-objects/reference/data-location/
-                    locationHint: doLocationHints[this.locationId],
-                });
-                const locationkeys = await cacheGroup.purge();
-                locationkeys.forEach((key) => keys.add(key));
-            })
-        );
-
-        return keys;
-    }
-}
-
-function getCacheObjectIdName(locationId: CacheLocationId, tag: string): string {
-    return `${locationId}:${tag}`;
-}

packages/cache-do/src/api.ts

@@ -1 +0,0 @@
-export * from './CacheObjectStub';

packages/cache-do/src/index.ts

@@ -1,9 +0,0 @@
-import { WorkerEntrypoint } from 'cloudflare:workers';
-
-export * from './CacheObject';
-
-export default class Worker extends WorkerEntrypoint {
-    fetch() {
-        return new Response('Hello, world!');
-    }
-}

packages/cache-do/turbo.json

@@ -1,8 +0,0 @@
-{
-    "extends": ["//"],
-    "tasks": {
-        "generate": {
-            "outputs": ["worker-configuration.d.ts"]
-        }
-    }
-}

packages/cache-do/wrangler.toml

@@ -1,27 +0,0 @@
-main = "./src/index.ts"
-name = "gitbook-open-cache"
-compatibility_date = "2024-09-02"
-
-durable_objects.bindings = [
-  {name = "CACHE", class_name = "CacheObject"}
-]
-
-migrations = [
-  {tag = "v1", new_classes = ["CacheObject"]}
-]
-
-[observability]
-enabled = false
-
-[env.preview]
-name = "gitbook-open-cache-preview"
-durable_objects.bindings = [
-  {name = "CACHE", class_name = "CacheObject"}
-]
-migrations = [
-  {tag = "v1", new_classes = ["CacheObject"]}
-]
-
-[env.preview.observability]
-enabled = true
-head_sampling_rate = 0.1

packages/cache-tags/package.json

@@ -10,7 +10,7 @@
     },
     "version": "0.3.1",
     "dependencies": {
-        "@gitbook/api": "^0.111.0",
+        "@gitbook/api": "catalog:",
         "assert-never": "^1.2.1"
     },
     "devDependencies": {

packages/cache-tags/src/index.ts

@@ -90,7 +90,7 @@ export function getCacheTag(
         | {
               tag: 'translation';
               organization: string;
-              translationSettings: string;
+              translation: string;
           }
 ): string {
     switch (spec.tag) {
@@ -115,23 +115,12 @@ export function getCacheTag(
         case 'openapi':
             return `organization:${spec.organization}:openapi:${spec.openAPISpec}`;
         case 'translation':
-            return `organization:${spec.organization}:translation:${spec.translationSettings}`;
+            return `organization:${spec.organization}:translation:${spec.translation}`;
         default:
             assertNever(spec);
     }
 }
 
-/**
- * Get the cache tag for a given URL.
- */
-export function getCacheTagForURL(url: string | URL) {
-    const parsedURL = url instanceof URL ? url : new URL(url);
-    return getCacheTag({
-        tag: 'url',
-        hostname: parsedURL.hostname,
-    });
-}
-
 /**
  * Get the tags for a computed content source.
  */
@@ -144,6 +133,10 @@ export function getComputedContentSourceCacheTags(
 ) {
     const tags: string[] = [];
 
+    if (!('dependencies' in source)) {
+        return tags;
+    }
+
     // We add the dependencies as tags, to ensure that the computed content is invalidated
     // when the dependencies are updated.
     const dependencies = Object.values(source.dependencies ?? {});
@@ -167,18 +160,18 @@ export function getComputedContentSourceCacheTags(
                         })
                     );
                     break;
-                case 'translation-language':
+                case 'translation':
                     tags.push(
                         getCacheTag({
                             tag: 'translation',
                             organization: inContext.organizationId,
-                            translationSettings: dependency.ref.translationSettings,
+                            translation: dependency.ref.translation,
                         })
                     );
                     break;
                 default:
                     // Do not throw for unknown dependency types
-                    // as it might mean we are lacking behind the API version
+                    // as it might mean we are lagging behind the API version
                     break;
             }
         });
@@ -194,9 +187,8 @@ export function getComputedContentSourceCacheTags(
     }
 
     // We invalidate the computed content when a new version of the integration is deployed.
-
     if (source.type.startsWith('integration:')) {
-        const integration = source.type.split(':')[1];
+        const integration = source.type.split(':')[1]!;
         tags.push(
             getCacheTag({
                 tag: 'integration',

packages/cache-tags/tsconfig.json

@@ -5,6 +5,7 @@
         "allowJs": true,
         "skipLibCheck": true,
         "strict": true,
+        "noUncheckedIndexedAccess": true,
         "noEmit": false,
         "declaration": true,
         "outDir": "dist",

packages/colors/CHANGELOG.md

@@ -1,5 +1,23 @@
 # @gitbook/colors
 
+## 0.4.0
+
+### Minor Changes
+
+- 17dd382: Add `original` background color step
+
+### Patch Changes
+
+- 193d591: Fix return type for `colorContrast`
+
+## 0.3.3
+
+### Patch Changes
+
+- c3f6b8c: Update chroma ratio per step
+- 5e975ab: Fix code highlighting for HTTP
+- f7a3470: Change lightness check for color step 9 to allow input colors with a higher-than-needed contrast
+
 ## 0.3.2
 
 ### Patch Changes

packages/colors/package.json

@@ -8,7 +8,7 @@
             "default": "./dist/index.js"
         }
     },
-    "version": "0.3.2",
+    "version": "0.4.0",
     "devDependencies": {
         "typescript": "^5.5.3"
     },

packages/colors/src/transformations.ts

@@ -8,7 +8,7 @@ type RGBColor = [number, number, number];
 type OKLABColor = { L: number; A: number; B: number };
 type OKLCHColor = { L: number; C: number; H: number };
 
-const D65 = [95.047, 100.0, 108.883]; // Reference white (D65)
+const D65 = [95.047, 100.0, 108.883] as const; // Reference white (D65)
 
 export enum ColorCategory {
     backgrounds = 'backgrounds',
@@ -19,7 +19,7 @@ export enum ColorCategory {
 }
 
 type ColorSubScale = {
-    [key: string]: number;
+    [key: string]: number | string;
 };
 
 /**
@@ -56,6 +56,8 @@ export const scale: Record<ColorCategory, ColorSubScale> = {
         solid: 9,
         /** Hovered solid backgrounds */
         'solid-hover': 10,
+        /** Original color */
+        original: 'original',
     },
     [ColorCategory.text]: {
         /** Very low-contrast text
@@ -211,16 +213,34 @@ export function colorScale(
     const result = [];
 
     for (let index = 0; index < mapping.length; index++) {
-        const targetL =
+        const step = mapping[index]!;
-            foregroundColor.L * mapping[index] + backgroundColor.L * (1 - mapping[index]);
+        const targetL = foregroundColor.L * step + backgroundColor.L * (1 - step);
 
-        if (index === 8 && !mix && Math.abs(baseColor.L - targetL) < 0.2) {
+        if (
+            index === 8 &&
+            !mix &&
+            (darkMode ? targetL - baseColor.L < 0.2 : baseColor.L - targetL < 0.2)
+        ) {
             // Original colour is close enough to target, so let's use the original colour as step 9.
             result.push(hex);
             continue;
         }
 
-        const chromaRatio = index === 8 || index === 9 ? 1 : index * 0.05;
+        const chromaRatio = (() => {
+            switch (index) {
+                // Step 9 and 10 have max chroma, meaning they are fully saturated.
+                case 8:
+                case 9:
+                    return 1;
+                // Step 11 and 12 have a reduced chroma
+                case 10:
+                    return 0.4;
+                case 11:
+                    return 0.1;
+                default:
+                    return index * 0.05;
+            }
+        })();
 
         const shade = {
             L: targetL, // Blend lightness
@@ -277,7 +297,7 @@ export function rgbArrayToHex(rgb: RGBColor): string {
 
 export function getColor(percentage: number, start: RGBColor, end: RGBColor) {
     const rgb = end.map((channel, index) => {
-        return Math.round(channel + percentage * (start[index] - channel));
+        return Math.round(channel + percentage * (start[index]! - channel));
     });
 
     return rgbArrayToHex(rgb as RGBColor);
@@ -374,14 +394,14 @@ export function xyzToLab65(xyz: [number, number, number]): {
     B: number;
 } {
     const [x, y, z] = xyz.map((v, i) => {
-        const scaled = v / D65[i];
+        const scaled = v / D65[i]!;
         return scaled > 0.008856 ? Math.cbrt(scaled) : 7.787 * scaled + 16 / 116;
     });
 
     return {
-        L: 116 * y - 16,
+        L: 116 * y! - 16,
-        A: 500 * (x - y),
+        A: 500 * (x! - y!),
-        B: 200 * (y - z),
+        B: 200 * (y! - z!),
     };
 }
 
@@ -401,7 +421,10 @@ export function dpsContrast(a: RGBColor, b: RGBColor) {
     return contrast < 7.5 ? 0 : contrast;
 }
 
-export function colorContrast(background: string, foreground: string[] = [LIGHT_BASE, DARK_BASE]) {
+export function colorContrast(
+    background: string,
+    foreground: string[] = [LIGHT_BASE, DARK_BASE]
+): string {
     const bg = hexToRgbArray(background);
 
     const best: { color?: RGBColor; contrast: number } = {
@@ -418,5 +441,5 @@ export function colorContrast(background: string, foreground: string[] = [LIGHT_
         }
     }
 
-    return best.color ? rgbArrayToHex(best.color) : foreground[0];
+    return best.color ? rgbArrayToHex(best.color) : foreground[0] || LIGHT_BASE;
 }

packages/colors/tsconfig.json

@@ -5,6 +5,7 @@
         "allowJs": true,
         "skipLibCheck": true,
         "strict": true,
+        "noUncheckedIndexedAccess": true,
         "noEmit": false,
         "declaration": true,
         "outDir": "dist",

packages/embed/.gitignore

@@ -0,0 +1,2 @@
+dist/
+standalone/

packages/embed/CHANGELOG.md

@@ -0,0 +1,25 @@
+# @gitbook/embed
+
+## 0.1.2
+
+### Patch Changes
+
+- 7508674: Fix bundling of packages
+
+## 0.1.1
+
+### Patch Changes
+
+- 6f368b5: Fix embed assistant window width on small screens
+
+## 0.1.0
+
+### Minor Changes
+
+- 81a6bd7: Improve API to control the GitBook embed
+
+### Patch Changes
+
+- 8927e8f: Initial version of the embed SDK.
+- Updated dependencies [25e2b40]
+  - @gitbook/icons@0.3.0

packages/embed/README.md

@@ -0,0 +1,49 @@
+# `@gitbook/embed`
+
+Embed the GitBook Docs Assistant in your product or website.
+
+# Usage
+
+## As a script from your docs site
+
+All GitBook docs site includes a script to easily embed the docs assistant as a widget on your website.
+
+The script is served at `https://docs.company.com/~gitbook/embed/script.js`.
+
+You can find the embed script from your docs site settings, or you can copy the following and replace the `docs.company.com` by your docs site hostname.
+
+```html
+<script src="https://docs.company.com/~gitbook/embed/script.js"></script>
+<script>
+window.GitBook('show');
+</script>
+```
+
+## As a package from NPM
+
+Install the package: `npm install @gitbook/embed` and import it in your web application:
+
+```tsx
+import { createGitBook } from '@gitbook/embed';
+
+const gitbook = createGitBook({
+    siteURL: 'https://docs.company.com'
+});
+
+const iframe = document.createElement('iframe');
+iframe.src = gitbook.getFrameURL();
+
+const frame = gitbook.createFrame(iframe);
+```
+
+## As React components
+
+After installing the NPM package, you can import prebuilt React components:
+
+```tsx
+import { GitBookProvider, GitBookAssistantFrame } from '@gitbook/embed/react';
+
+<GitBookProvider siteURL="https://docs.company.com">
+    <GitBookAssistantFrame />
+</GitBookProvider>
+```

packages/embed/package.json

@@ -0,0 +1,37 @@
+{
+    "name": "@gitbook/embed",
+    "description": "Embeddable components for GitBook",
+    "type": "module",
+    "exports": {
+        ".": {
+            "types": "./dist/index.d.ts",
+            "default": "./dist/index.js"
+        },
+        "./react": {
+            "types": "./dist/react/index.d.ts",
+            "default": "./dist/react/index.js"
+        }
+    },
+    "version": "0.1.2",
+    "dependencies": {
+        "@gitbook/api": "catalog:",
+        "@gitbook/icons": "workspace:",
+        "bidc": "catalog:"
+    },
+    "peerDependencies": {
+        "react": "^18.0.0"
+    },
+    "devDependencies": {
+        "tsdown": "catalog:",
+        "typescript": "^5.5.3",
+        "react": "^19.0.0"
+    },
+    "scripts": {
+        "build": "bun run build-lib && bun run build-standalone",
+        "build-lib": "tsdown",
+        "build-standalone": "bun build src/standalone/index.ts --bundle --minify --outdir=standalone",
+        "clean": "rm -rf ./dist",
+        "typecheck": "tsc --noEmit"
+    },
+    "files": ["dist", "README.md", "CHANGELOG.md"]
+}

packages/embed/src/client/createGitBook.ts

@@ -0,0 +1,61 @@
+import { type GitBookFrameClient, createGitBookFrame } from './createGitBookFrame';
+
+export type CreateGitBookOptions = {
+    /**
+     * URL of the GitBook site to embed.
+     */
+    siteURL: string;
+};
+
+export type GetFrameURLOptions = {
+    /**
+     * Authentication to use for the frame.
+     */
+    visitor?: {
+        /**
+         * Signed JWT token for Adaptive Content or Visitor Authentication to use.
+         */
+        token?: string;
+
+        /**
+         * Unsigned claims to pass to the frame.
+         * You can use these claims in dynamic expressions using `visitor.claims.unsigned.<claim-name>`.
+         */
+        unsignedClaims?: Record<string, unknown>;
+    };
+};
+
+export type GitBookClient = {
+    /**
+     * Get the URL for a GitBook frame.
+     */
+    getFrameURL: (options: GetFrameURLOptions) => string;
+    /**
+     * Create a new GitBook frame.
+     */
+    createFrame: (iframe: HTMLIFrameElement) => GitBookFrameClient;
+};
+
+export function createGitBook(options: CreateGitBookOptions) {
+    const client: GitBookClient = {
+        getFrameURL: (frameOptions) => {
+            const url = new URL(options.siteURL);
+            url.pathname = `${url.pathname.endsWith('/') ? url.pathname : `${url.pathname}/`}~gitbook/embed/assistant`;
+
+            if (frameOptions.visitor?.token) {
+                url.searchParams.set('token', frameOptions.visitor.token);
+            }
+
+            if (frameOptions.visitor?.unsignedClaims) {
+                Object.entries(frameOptions.visitor.unsignedClaims).forEach(([key, value]) => {
+                    url.searchParams.set(`visitor.${key}`, String(value));
+                });
+            }
+
+            return url.toString();
+        },
+        createFrame: (iframe) => createGitBookFrame(iframe),
+    };
+
+    return client;
+}

packages/embed/src/client/createGitBookFrame.ts

@@ -0,0 +1,98 @@
+import { createChannel } from 'bidc';
+import type {
+    FrameToParentMessage,
+    GitBookEmbeddableConfiguration,
+    ParentToFrameMessage,
+} from './protocol';
+
+export type GitBookFrameClient = {
+    /**
+     * Navigate to a page by its path.
+     */
+    navigateToPage: (path: string) => void;
+
+    /**
+     * Navigate to the assistant.
+     */
+    navigateToAssistant: () => void;
+
+    /**
+     * Post a message to the chat.
+     */
+    postUserMessage: (message: string) => void;
+
+    /**
+     * Clear the chat.
+     */
+    clearChat: () => void;
+
+    /**
+     * Set the placeholder settings.
+     */
+    configure: (settings: Partial<GitBookEmbeddableConfiguration>) => void;
+
+    /**
+     * Register an event listener.
+     */
+    on: (event: string, listener: (...args: any[]) => void) => () => void;
+};
+
+/**
+ * Create a client to communicate with the GitBook Assistant frame.
+ */
+export function createGitBookFrame(iframe: HTMLIFrameElement): GitBookFrameClient {
+    if (!iframe.contentWindow) {
+        throw new Error('Iframe must have a content window');
+    }
+    const channel = createChannel(iframe.contentWindow);
+
+    channel.receive((message: FrameToParentMessage) => {
+        console.log('[gitbook:embed] received message', message);
+        if (message.type === 'close') {
+            const listeners = events.get('close') || [];
+            if (listeners) {
+                listeners.forEach((listener) => listener());
+            }
+        }
+    });
+
+    const sendToFrame = (message: ParentToFrameMessage) => {
+        console.log('[gitbook:embed] send message', message);
+        channel.send(message);
+    };
+
+    const events = new Map<string, Array<(...args: any[]) => void>>();
+
+    const configuration: GitBookEmbeddableConfiguration = {
+        buttons: [],
+        welcomeMessage: '',
+        suggestions: [],
+        tools: [],
+    };
+
+    return {
+        navigateToPage: (pagePath) => {
+            sendToFrame({ type: 'navigateToPage', pagePath });
+        },
+        navigateToAssistant: () => {
+            sendToFrame({ type: 'navigateToAssistant' });
+        },
+        postUserMessage: (message) => sendToFrame({ type: 'postUserMessage', message }),
+        configure: (settings) => {
+            Object.assign(configuration, settings);
+            sendToFrame({ type: 'configure', settings: configuration });
+        },
+        clearChat: () => sendToFrame({ type: 'clearChat' }),
+        on: (event, listener) => {
+            const listeners = events.get(event) || [];
+            listeners.push(listener);
+            events.set(event, listeners);
+            return () => {
+                events.set(
+                    event,
+                    listeners.filter((l) => l !== listener)
+                );
+            };
+        },
+    };
+}

packages/embed/src/client/index.ts

@@ -0,0 +1,3 @@
+export * from './createGitBook';
+export * from './createGitBookFrame';
+export * from './protocol';

packages/embed/src/client/protocol.ts

@@ -0,0 +1,90 @@
+import type { AIToolCallResult, AIToolDefinition } from '@gitbook/api';
+import type { IconName } from '@gitbook/icons';
+
+/**
+ * Custom tool definition to be passed to the AI assistant.
+ */
+export type GitBookToolDefinition = AIToolDefinition & {
+    /**
+     * Confirmation action to be displayed to the user before executing the tool.
+     */
+    confirmation?: {
+        icon?: IconName;
+        label: string;
+    };
+
+    /**
+     * Callback when the tool is executed.
+     * The input is provided by the AI assistant following the input schema of the tool.
+     */
+    execute: (input: object) => Promise<Pick<AIToolCallResult, 'output' | 'summary'>>;
+};
+
+/**
+ * Custom button definition to be passed to the embeddable GitBook.
+ */
+export type GitBookEmbeddableButtonDefinition = {
+    /**
+     * Icon to be displayed in the button.
+     */
+    icon: IconName;
+
+    /**
+     * Label to be displayed in the button.
+     */
+    label: string;
+
+    /**
+     * Callback when the button is clicked.
+     */
+    onClick: () => void | Promise<void>;
+};
+
+/**
+ * Overall configuration for the layout of the embeddable GitBook.
+ */
+export type GitBookEmbeddableConfiguration = {
+    /**
+     * Buttons to be displayed in the header of the embeddable GitBook.
+     */
+    buttons: GitBookEmbeddableButtonDefinition[];
+
+    /** Message to be displayed in the welcome page. */
+    welcomeMessage: string;
+
+    /** Suggestions of questions to be displayed in the welcome page. */
+    suggestions: string[];
+
+    /** Tools to be provided to the assistant. */
+    tools: GitBookToolDefinition[];
+};
+
+/**
+ * Messages sent from the parent to the frame.
+ */
+export type ParentToFrameMessage =
+    | {
+          type: 'postUserMessage';
+          message: string;
+      }
+    | {
+          type: 'clearChat';
+      }
+    | {
+          type: 'configure';
+          settings: GitBookEmbeddableConfiguration;
+      }
+    | {
+          type: 'navigateToPage';
+          pagePath: string;
+      }
+    | {
+          type: 'navigateToAssistant';
+      };
+
+/**
+ * Messages sent from the frame to the parent.
+ */
+export type FrameToParentMessage = {
+    type: 'close';
+};

packages/embed/src/index.ts

@@ -0,0 +1 @@
+export * from './client';

packages/embed/src/react/GitBookFrame.tsx

@@ -0,0 +1,51 @@
+import React from 'react';
+import type {
+    GetFrameURLOptions,
+    GitBookEmbeddableConfiguration,
+    GitBookFrameClient,
+} from '../client';
+import { useGitBook } from './GitBookProvider';
+
+export type GitBookFrameProps = {
+    className?: string;
+} & GetFrameURLOptions &
+    GitBookEmbeddableConfiguration;
+
+/**
+ * Render a frame with the GitBook Assistant in it.
+ */
+export function GitBookFrame(props: GitBookFrameProps) {
+    const { className, visitor, buttons, welcomeMessage, suggestions, tools } = props;
+
+    const frameRef = React.useRef<HTMLIFrameElement>(null);
+    const gitbook = useGitBook();
+    const [gitbookFrame, setGitbookFrame] = React.useState<GitBookFrameClient | null>(null);
+
+    const frameURL = React.useMemo(() => gitbook.getFrameURL({ visitor }), [gitbook, visitor]);
+
+    React.useEffect(() => {
+        if (frameRef.current) {
+            setGitbookFrame(gitbook.createFrame(frameRef.current));
+        }
+    }, [gitbook]);
+
+    React.useEffect(() => {
+        gitbookFrame?.configure({
+            buttons,
+            welcomeMessage,
+            suggestions,
+            tools,
+        });
+    }, [gitbookFrame, buttons, welcomeMessage, suggestions, tools]);
+
+    return (
+        <iframe
+            title="GitBook"
+            ref={frameRef}
+            src={frameURL}
+            width="100%"
+            height="100%"
+            className={className}
+        />
+    );
+}

packages/embed/src/react/GitBookProvider.tsx

@@ -0,0 +1,36 @@
+'use client';
+
+import * as React from 'react';
+import { type CreateGitBookOptions, createGitBook } from '../client';
+import { GitBookContext } from './context';
+
+/**
+ * Provider for the GitBook client.
+ */
+export function GitBookProvider(props: React.PropsWithChildren<CreateGitBookOptions>) {
+    const { siteURL, children } = props;
+
+    const options = React.useMemo(
+        () => ({
+            siteURL,
+        }),
+        [siteURL]
+    );
+
+    const client = React.useMemo(() => createGitBook(options), [options]);
+
+    return <GitBookContext.Provider value={client}>{children}</GitBookContext.Provider>;
+}
+
+/**
+ * Hook to access the GitBook client.
+ */
+export function useGitBook() {
+    const context = React.useContext(GitBookContext);
+
+    if (!context) {
+        throw new Error('This component must be used within a <GitBookProvider />');
+    }
+
+    return context;
+}

packages/embed/src/react/context.ts

@@ -0,0 +1,6 @@
+'use client';
+
+import * as React from 'react';
+import type { GitBookClient } from '../client';
+
+export const GitBookContext = React.createContext<GitBookClient | null>(null);

packages/embed/src/react/index.ts

@@ -0,0 +1,2 @@
+export * from './GitBookProvider';
+export * from './GitBookFrame';

packages/embed/src/standalone/index.ts

@@ -0,0 +1,178 @@
+import './style.css';
+
+import {
+    type CreateGitBookOptions,
+    type GetFrameURLOptions,
+    type GitBookClient,
+    type GitBookEmbeddableConfiguration,
+    type GitBookFrameClient,
+    createGitBook,
+} from '../client';
+
+export type GitBook = () => void;
+
+type StandaloneCalls =
+    // Initialize the widget
+    | ['init', CreateGitBookOptions, GetFrameURLOptions]
+    // Unload the widget
+    | ['unload']
+    // Show the widget
+    | ['show']
+    // Hide the widget
+    | ['hide']
+    // Open the window
+    | ['open']
+    // Close the window
+    | ['close']
+    // Toggle the window
+    | ['toggle']
+    // Post a user message
+    | ['postUserMessage', string]
+    // Clear the chat
+    | ['clearChat']
+    // Configure the embed
+    | ['configure', Partial<GitBookEmbeddableConfiguration>]
+    // Navigate to a page
+    | ['navigateToPage', string]
+    // Navigate to the assistant
+    | ['navigateToAssistant'];
+
+export type GitBookStandalone = ((...args: StandaloneCalls) => void) & {
+    q?: StandaloneCalls[];
+};
+
+const widgetButton = document.createElement('button');
+widgetButton.id = 'gitbook-widget-button';
+widgetButton.addEventListener('click', () => {
+    GitBook('toggle');
+});
+widgetButton.innerHTML = `
+    <span id="gitbook-widget-button-icon"></span>
+    <span id="gitbook-widget-button-label">Ask</span>
+`;
+
+const widgetWindow = document.createElement('div');
+widgetWindow.id = 'gitbook-widget-window';
+widgetWindow.classList.add('hidden');
+
+document.body.appendChild(widgetButton);
+document.body.appendChild(widgetWindow);
+
+let widgetIframe: HTMLIFrameElement | undefined;
+let _client: GitBookClient | undefined;
+let _frame: GitBookFrameClient | undefined;
+let frameOptions: GetFrameURLOptions | undefined;
+let frameConfiguration: GitBookEmbeddableConfiguration = {
+    buttons: [],
+    welcomeMessage: '',
+    suggestions: [],
+    tools: [],
+};
+
+function getClient() {
+    if (!_client) {
+        throw new Error(
+            'GitBook client not initialized. Call GitBook("init", { siteURL: "..." }) first.'
+        );
+    }
+    return _client;
+}
+
+function getIframe() {
+    if (!widgetIframe || !_frame) {
+        const client = getClient();
+
+        widgetIframe?.remove();
+        widgetIframe = document.createElement('iframe');
+        widgetIframe.id = 'gitbook-widget-iframe';
+        widgetIframe.src = client.getFrameURL({
+            ...frameOptions,
+        });
+        widgetWindow.appendChild(widgetIframe);
+
+        _frame = client.createFrame(widgetIframe);
+    }
+    return { iframe: widgetIframe, frame: _frame };
+}
+
+const GitBook = (...args: StandaloneCalls) => {
+    switch (args[0]) {
+        case 'init':
+            if (_client) {
+                throw new Error(
+                    'GitBook client already initialized. Call GitBook("unload") first.'
+                );
+            }
+            _client = createGitBook(args[1]);
+            frameOptions = args[2];
+            break;
+        case 'unload':
+            _client = undefined;
+            _frame = undefined;
+            widgetIframe?.remove();
+            widgetWindow.classList.add('hidden');
+            break;
+        case 'show':
+            widgetButton.classList.remove('hidden');
+            break;
+        case 'hide':
+            widgetButton.classList.add('hidden');
+            break;
+        case 'open':
+            widgetWindow.classList.remove('hidden');
+            widgetButton.classList.add('open');
+            getIframe();
+            break;
+        case 'toggle':
+            widgetWindow.classList.toggle('hidden');
+            widgetButton.classList.toggle('open');
+            getIframe();
+            break;
+        case 'close':
+            widgetWindow.classList.add('hidden');
+            widgetButton.classList.remove('open');
+            break;
+        case 'postUserMessage':
+            getIframe().frame.postUserMessage(args[1]);
+            break;
+        case 'configure':
+            frameConfiguration = {
+                ...frameConfiguration,
+                ...args[1],
+            };
+            getIframe().frame.configure({
+                ...frameConfiguration,
+                buttons: [
+                    ...frameConfiguration.buttons,
+
+                    // Always include a close button
+                    {
+                        icon: 'close',
+                        label: 'Close',
+                        onClick: () => {
+                            GitBook('close');
+                        },
+                    },
+                ],
+            });
+            break;
+        case 'clearChat':
+            getIframe().frame.clearChat();
+            break;
+        case 'navigateToPage':
+            getIframe().frame.navigateToPage(args[1]);
+            break;
+        case 'navigateToAssistant':
+            getIframe().frame.navigateToAssistant();
+            break;
+    }
+};
+
+// @ts-expect-error - GitBook is not defined in the global scope
+const precalls = (window.GitBook as GitBookStandalone | undefined)?.q ?? [];
+
+// @ts-expect-error - GitBook is not defined in the global scope
+window.GitBook = GitBook;
+precalls.forEach((call) => GitBook(...call));
+
+GitBook('configure', {});

packages/embed/src/standalone/style.css

@@ -0,0 +1,171 @@
+:root {
+    --gitbook-widget-top: 1rem;
+    --gitbook-widget-bottom: 1rem;
+    --gitbook-widget-right: 1rem;
+    --gitbook-widget-left: 1rem;
+
+    --gitbook-widget-button-height: 46px;
+
+    --gitbook-widget-radius: .5rem;
+    --gitbook-widget-text-size: 1rem;
+    --gitbook-widget-text-color: #656973;
+    --gitbook-widget-border-color: #e5e5e5;
+
+    --gitbook-widget-background-translucent: rgba(255, 255, 255, 0.9);
+    --gitbook-widget-background-translucent-hover: rgba(250, 250, 250, 0.9);
+    --gitbook-widget-background-solid: #FFFFFF;
+    --gitbook-widget-background-solid-hover: #FBFBFB;
+
+    --gitbook-widget-icon-size: 1.25rem;
+
+    --gitbook-widget-window-width: 28rem; /* 448px */
+    --gitbook-widget-window-height: 40rem; /* 640px */
+    --gitbook-widget-window-spacing: .5rem; /* Spacing between the button and the window */
+    --gitbook-widget-window-bottom: calc(var(--gitbook-widget-bottom) + var(--gitbook-widget-button-height) + var(--gitbook-widget-window-spacing));
+
+    --gitbook-widget-transition-duration-fast: 0.2s;
+    --gitbook-widget-transition-duration-slow: 0.5s;
+    --gitbook-widget-easing: cubic-bezier(0.25, 1, 0.5, 1);
+    --gitbook-widget-easing-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
+}
+
+* {
+    box-sizing: border-box;
+}
+
+/* Button */
+#gitbook-widget-button {
+    position: fixed;
+    bottom: var(--gitbook-widget-bottom);
+    right: var(--gitbook-widget-right);
+    height: var(--gitbook-widget-button-height);
+    z-index: 9999;
+
+    display: flex;
+    align-items: center;
+    flex-direction: row-reverse;
+    gap: .5rem;
+    padding: .75rem 1rem;
+
+    border-radius: 100px;
+    border: 1px solid var(--gitbook-widget-border-color);
+    background-color: var(--gitbook-widget-background-translucent);
+    backdrop-filter: blur(16px);
+
+    font-size: var(--gitbook-widget-text-size);
+    color: var(--gitbook-widget-text-color);
+
+    box-shadow: 0 1px 3px 0 rgba(0,0,0,0.05), 0 1px 2px -1px rgba(0,0,0,0.05);
+    transition: all var(--gitbook-widget-transition-duration-fast) var(--gitbook-widget-easing);
+
+    cursor:pointer;
+    animation: gitbook-widget-present var(--gitbook-widget-transition-duration-slow) var(--gitbook-widget-easing-bounce);
+}
+
+#gitbook-widget-button:hover, #gitbook-widget-button:focus-visible {
+    background-color: var(--gitbook-widget-background-translucent-hover);
+}
+#gitbook-widget-button:hover, #gitbook-widget-button:focus-visible {
+    transform: translateY(-1px);
+    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
+}
+#gitbook-widget-button:active {
+    transform: translateY(0);
+    box-shadow: 0 1px 3px 0 rgba(0,0,0,0.05), 0 1px 2px -1px rgba(0,0,0,0.05);
+}
+
+@media (prefers-contrast: more) {
+    #gitbook-widget-button {
+        background-color: var(--gitbook-widget-background-solid);
+    }
+    #gitbook-widget-button:hover, #gitbook-widget-button:focus-visible {
+        background-color: var(--gitbook-widget-background-solid-hover);
+    }
+}
+
+#gitbook-widget-button.hidden {
+    display: none;
+}
+
+#gitbook-widget-button.open {
+    padding: .75rem;
+    gap: 0;
+}
+
+/* Button: Icon */
+#gitbook-widget-button-icon {
+    width: var(--gitbook-widget-icon-size);
+    height: var(--gitbook-widget-icon-size);
+    mask-image: url("https://static-2v.gitbook.com/~gitbook/static/icons/svgs/custom-icons/gitbook-assistant.svg?v=2");
+    mask-size: contain;
+    mask-repeat: no-repeat;
+    mask-position: center;
+    background-color: currentColor;
+}
+
+#gitbook-widget-button.open #gitbook-widget-button-icon {
+    mask-image: url('https://ka-p.fontawesome.com/releases/v6.6.0/svgs/regular/close.svg?v=2&token=a463935e93');
+}
+
+/* Button: Label */
+#gitbook-widget-button.open #gitbook-widget-button-label {
+    display: none;
+}
+
+/* Window */
+#gitbook-widget-window {
+    position: fixed;
+    bottom: var(--gitbook-widget-window-bottom);
+    right: var(--gitbook-widget-right);
+    z-index: 9998;
+    width: calc(min(var(--gitbook-widget-window-width), calc(100vw - var(--gitbook-widget-right) - var(--gitbook-widget-left))));
+    height: calc(min(var(--gitbook-widget-window-height), calc(100vh - var(--gitbook-widget-window-bottom) - var(--gitbook-widget-top))));
+    background-color: var(--gitbook-widget-background-solid);
+    border: 1px solid var(--gitbook-widget-border-color);
+    border-radius: var(--gitbook-widget-radius);
+    box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
+    overflow: hidden;
+    transition-property: transform, opacity, display;
+    transition-duration: var(--gitbook-widget-transition-duration-slow);
+    transition-timing-function: var(--gitbook-widget-easing-bounce);
+    transform-origin: bottom right;
+    transition-behavior: allow-discrete;
+}
+
+@starting-style {
+    #gitbook-widget-window {
+        opacity: 0;
+        transform: scale(0.9);
+    }
+}
+
+body:has(#gitbook-widget-button.hidden) #gitbook-widget-window {
+    bottom: var(--gitbook-widget-bottom);
+}
+
+#gitbook-widget-window.hidden {
+    transition-property: transform, opacity, display;
+    transition-duration: var(--gitbook-widget-transition-duration-fast);
+    transition-timing-function: var(--gitbook-widget-easing);
+    transition-behavior: allow-discrete;
+    display: none;
+    opacity: 0;
+    transform: scale(0.9);
+}
+
+#gitbook-widget-iframe {
+    width: 100%;
+    height: 100%;
+    border: none;
+}
+
+@keyframes gitbook-widget-present {
+    from {
+        opacity: 0;
+        transform: scale(0.9);
+    }
+    to {
+        opacity: 1;
+        transform: scale(1);
+    }
+}

packages/embed/tsconfig.json

@@ -13,9 +13,10 @@
         "moduleResolution": "bundler",
         "resolveJsonModule": true,
         "isolatedModules": true,
+        "jsx": "react-jsx",
         "incremental": true,
-        "types": ["./worker-configuration.d.ts"]
+        "types": []
     },
-    "include": ["src/**/*.ts"],
+    "include": ["src/**/*.ts", "src/**/*.tsx"],
     "exclude": ["node_modules"]
 }

packages/embed/tsdown.config.ts

@@ -0,0 +1,9 @@
+import { defineConfig } from 'tsdown';
+
+export default defineConfig([
+    {
+        entry: ['src/index.ts', 'src/react/index.ts'],
+        dts: true,
+        format: ['esm'],
+    },
+]);

packages/expr/.gitignore

@@ -0,0 +1 @@
+dist

packages/expr/CHANGELOG.md

@@ -0,0 +1,35 @@
+# @gitbook/expr
+
+## 1.2.1
+
+### Patch Changes
+
+- a629900: Add dev script for @gitbook/expr
+
+## 1.2.0
+
+### Minor Changes
+
+- 6da3655: Fix exports in gitbook/expr package.json
+
+## 1.1.1
+
+### Patch Changes
+
+- 3548fa6: Fix eval-estree-expr named import
+
+## 1.1.0
+
+### Minor Changes
+
+- e1ff17e: Fix bundling of gitbook/expr package
+
+### Patch Changes
+
+- 8ff1e3b: Add support for every/some array methods
+
+## 1.0.0
+
+### Major Changes
+
+- ada195d: Publish gitbook/expr package to help evaluate user defined expressions.

packages/expr/README.md

@@ -0,0 +1,3 @@
+# `@gitbook/expr`
+
+Safely evaluate & parse user-defined GitBook expressions.

packages/expr/package.json

@@ -0,0 +1,38 @@
+{
+    "name": "@gitbook/expr",
+    "description": "Safely evaluate & parse user-defined GitBook expressions.",
+    "version": "1.2.1",
+    "type": "module",
+    "exports": {
+        ".": {
+            "types": "./dist/index.d.ts",
+            "import": "./dist/index.js",
+            "default": "./dist/index.js"
+        }
+    },
+    "sideEffects": false,
+    "dependencies": {
+        "eval-estree-expression": "github:jonschlinkert/eval-estree-expression#9cf28d2",
+        "acorn": "^8.14.0",
+        "acorn-loose": "8.4.0",
+        "acorn-walk": "^8.3.4",
+        "escodegen": "^2.1.0",
+        "assert-never": "^1.2.1"
+    },
+    "devDependencies": {
+        "bun-types": "^1.1.20",
+        "tsdown": "catalog:",
+        "@types/estree": "^1.0.6",
+        "@babel/types": "^7.26.0",
+        "@types/json-schema": "^7.0.15",
+        "@types/escodegen": "^0.0.10"
+    },
+    "scripts": {
+        "build": "tsdown",
+        "typecheck": "tsc --noEmit",
+        "unit": "bun test",
+        "clean": "rm -rf ./dist",
+        "dev": "bun run build -- --watch"
+    },
+    "files": ["dist", "README.md", "CHANGELOG.md"]
+}

packages/expr/src/__tests__/autocomplete.test.ts

@@ -0,0 +1,889 @@
+import { describe, expect, it } from 'bun:test';
+
+import { ExpressionRuntime } from '../runtime';
+import {
+    SymbolArray,
+    SymbolBoolean,
+    SymbolNumber,
+    SymbolObject,
+    SymbolString,
+    SymbolType,
+    SymbolsTable,
+} from '../symbols';
+import {
+    type AutocompleteSuggestions,
+    type AutocompleteSymbolSuggestion,
+    SUPPORTED_BINARY_OPERATORS,
+    SUPPORTED_CONDITIONAL_OPERATORS,
+    SUPPORTED_LOGICAL_OPERATORS,
+} from '../types';
+
+describe('autocomplete', () => {
+    const runtime = new ExpressionRuntime();
+    const visitorClaimsHelloArraySymbol = SymbolArray({
+        name: 'hello',
+        description: 'An array of string',
+        items: SymbolString(),
+    });
+    const symbols = {
+        visitor: SymbolObject({
+            name: 'visitor',
+            properties: {
+                claims: SymbolObject({
+                    name: 'claims',
+                    description: 'The claims contained in the visitor JWT token',
+                    properties: {
+                        key: SymbolString({ name: 'key' }),
+                        flags: SymbolObject({
+                            name: 'flags',
+                            properties: {
+                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                            },
+                            methods: [],
+                        }),
+                        hello: visitorClaimsHelloArraySymbol,
+                        role: SymbolString({
+                            name: 'role',
+                            enum: ['admin', 'editor', 'reader'],
+                        }),
+                    },
+                    methods: [],
+                }),
+            },
+            methods: [],
+        }),
+    };
+    const context = new SymbolsTable(symbols);
+    const SCENARIOS: Array<{
+        expressionWithCursor: string;
+        expectedSuggestions: AutocompleteSuggestions;
+    }> = [
+        {
+            expressionWithCursor: 'visit<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'visitor',
+                            properties: {
+                                claims: SymbolObject({
+                                    name: 'claims',
+                                    description: 'The claims contained in the visitor JWT token',
+                                    properties: {
+                                        key: SymbolString({ name: 'key' }),
+                                        flags: SymbolObject({
+                                            name: 'flags',
+                                            properties: {
+                                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                                            },
+                                            methods: [],
+                                        }),
+                                        hello: SymbolArray({
+                                            name: 'hello',
+                                            description: 'An array of string',
+                                            items: SymbolString(),
+                                        }),
+                                        role: SymbolString({
+                                            name: 'role',
+                                            enum: ['admin', 'editor', 'reader'],
+                                        }),
+                                    },
+                                    methods: [],
+                                }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor',
+                        parentRef: undefined,
+                        childrenRefs: ['visitor.claims'],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor<cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'claims',
+                            description: 'The claims contained in the visitor JWT token',
+                            properties: {
+                                key: SymbolString({ name: 'key' }),
+                                flags: SymbolObject({
+                                    name: 'flags',
+                                    properties: {
+                                        FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                        FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                        FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                        FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                                    },
+                                    methods: [],
+                                }),
+                                hello: SymbolArray({
+                                    name: 'hello',
+                                    description: 'An array of string',
+                                    items: SymbolString(),
+                                }),
+                                role: SymbolString({
+                                    name: 'role',
+                                    enum: ['admin', 'editor', 'reader'],
+                                }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor.claims',
+                        parentRef: 'visitor',
+                        childrenRefs: [
+                            'visitor.claims.key',
+                            'visitor.claims.flags',
+                            'visitor.claims.hello',
+                            'visitor.claims.role',
+                        ],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolString({ name: 'key' }),
+                        ref: 'visitor.claims.key',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.key.length',
+                            'visitor.claims.key.at',
+                            'visitor.claims.key.endsWith',
+                            'visitor.claims.key.includes',
+                        ],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'flags',
+                            properties: {
+                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor.claims.flags',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.flags.FLAG1',
+                            'visitor.claims.flags.FLAG2',
+                            'visitor.claims.flags.FLAG3',
+                            'visitor.claims.flags.FLAG4',
+                        ],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolArray({
+                            name: 'hello',
+                            description: 'An array of string',
+                            items: SymbolString(),
+                        }),
+                        ref: 'visitor.claims.hello',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.hello.length',
+                            'visitor.claims.hello.at',
+                            'visitor.claims.hello.includes',
+                            'visitor.claims.hello.some',
+                            'visitor.claims.hello.every',
+                        ],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolString({
+                            name: 'role',
+                            enum: ['admin', 'editor', 'reader'],
+                        }),
+                        ref: 'visitor.claims.role',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.role.length',
+                            'visitor.claims.role.at',
+                            'visitor.claims.role.endsWith',
+                            'visitor.claims.role.includes',
+                        ],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.ke<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolString({ name: 'key' }),
+                        ref: 'visitor.claims.key',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.key.length',
+                            'visitor.claims.key.at',
+                            'visitor.claims.key.endsWith',
+                            'visitor.claims.key.includes',
+                        ],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.h<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolArray({
+                            name: 'hello',
+                            description: 'An array of string',
+                            items: SymbolString(),
+                        }),
+                        ref: 'visitor.claims.hello',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.hello.length',
+                            'visitor.claims.hello.at',
+                            'visitor.claims.hello.includes',
+                            'visitor.claims.hello.some',
+                            'visitor.claims.hello.every',
+                        ],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.hello.<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolNumber({
+                            name: 'length',
+                            description: `The length data property of an Array instance represents the number of elements in that array.
+                The value is an unsigned, 32-bit integer that is always numerically greater than the highest index in the array.`,
+                            link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/length',
+                        }),
+                        ref: 'visitor.claims.hello.length',
+                        parentRef: 'visitor.claims.hello',
+                        childrenRefs: [],
+                    },
+                },
+                ...visitorClaimsHelloArraySymbol.methods.map<AutocompleteSymbolSuggestion>(
+                    (method) => ({
+                        type: 'symbol',
+                        symbol: {
+                            definition: method,
+                            ref: `visitor.claims.hello.${method.name}`,
+                            parentRef: 'visitor.claims.hello',
+                            childrenRefs: [],
+                        },
+                    })
+                ),
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.f<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'flags',
+                            properties: {
+                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor.claims.flags',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.flags.FLAG1',
+                            'visitor.claims.flags.FLAG2',
+                            'visitor.claims.flags.FLAG3',
+                            'visitor.claims.flags.FLAG4',
+                        ],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.fl<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'flags',
+                            properties: {
+                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor.claims.flags',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.flags.FLAG1',
+                            'visitor.claims.flags.FLAG2',
+                            'visitor.claims.flags.FLAG3',
+                            'visitor.claims.flags.FLAG4',
+                        ],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG1' }),
+                        ref: 'visitor.claims.flags.FLAG1',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG2' }),
+                        ref: 'visitor.claims.flags.FLAG2',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG3' }),
+                        ref: 'visitor.claims.flags.FLAG3',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG4' }),
+                        ref: 'visitor.claims.flags.FLAG4',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FL<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG1' }),
+                        ref: 'visitor.claims.flags.FLAG1',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG2' }),
+                        ref: 'visitor.claims.flags.FLAG2',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG3' }),
+                        ref: 'visitor.claims.flags.FLAG3',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolBoolean({ name: 'FLAG4' }),
+                        ref: 'visitor.claims.flags.FLAG4',
+                        parentRef: 'visitor.claims.flags',
+                        childrenRefs: [],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1<cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.key <cur>',
+            expectedSuggestions: [...SUPPORTED_BINARY_OPERATORS].map((op) => ({
+                type: 'operator',
+                ...op,
+            })),
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 <cur>',
+            expectedSuggestions: [
+                ...[...SUPPORTED_BINARY_OPERATORS, ...SUPPORTED_LOGICAL_OPERATORS].filter((op) =>
+                    ['==', '!=', '===', '!==', '&&', '||'].includes(op.operator)
+                ),
+                ...SUPPORTED_CONDITIONAL_OPERATORS,
+            ].map((op) => ({
+                type: 'operator',
+                ...op,
+            })),
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 =<cur>',
+            expectedSuggestions: SUPPORTED_BINARY_OPERATORS.filter((op) =>
+                ['==', '==='].includes(op.operator)
+            ).map((op) => ({
+                type: 'operator',
+                ...op,
+            })),
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 ==<cur>',
+            expectedSuggestions: SUPPORTED_BINARY_OPERATORS.filter(
+                (op) => op.operator === '==='
+            ).map((op) => ({
+                type: 'operator',
+                ...op,
+            })),
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 !<cur>',
+            expectedSuggestions: SUPPORTED_BINARY_OPERATORS.filter((op) =>
+                ['!=', '!=='].includes(op.operator)
+            ).map((op) => ({
+                type: 'operator',
+                ...op,
+            })),
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 !=<cur>',
+            expectedSuggestions: SUPPORTED_BINARY_OPERATORS.filter(
+                (op) => op.operator === '!=='
+            ).map((op) => ({
+                type: 'operator',
+                ...op,
+            })),
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == <cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.Boolean, data: true },
+                },
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.Boolean, data: false },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == t<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.Boolean, data: true },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == tr<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.Boolean, data: true },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == true<cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == f<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.Boolean, data: false },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == fa<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.Boolean, data: false },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == non<cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == false<cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == <cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'admin' },
+                },
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'editor' },
+                },
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'reader' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == ad<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'admin' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == admin<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'admin' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == "ad<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'admin' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == "admin<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'admin' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == "admin"<cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == edit<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'editor' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == "edit<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'editor' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == editor<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: { kind: 'direct', type: SymbolType.String, data: 'editor' },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.role == "editor"<cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.hello == <cur>',
+            expectedSuggestions: [],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.hello[1] == <cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: {
+                        kind: 'in-array',
+                        srcSymbol: visitorClaimsHelloArraySymbol,
+                        matchedLiteralString: '',
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.hello[1] == "test<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'literal-value',
+                    value: {
+                        kind: 'in-array',
+                        srcSymbol: visitorClaimsHelloArraySymbol,
+                        matchedLiteralString: '"test',
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 == true <cur>',
+            expectedSuggestions: [
+                ...SUPPORTED_LOGICAL_OPERATORS.filter((op) => ['&&', '||'].includes(op.operator)),
+                ...SUPPORTED_CONDITIONAL_OPERATORS,
+            ].map((op) => ({
+                type: 'operator',
+                ...op,
+            })),
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 !== true && v<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'visitor',
+                            properties: {
+                                claims: SymbolObject({
+                                    name: 'claims',
+                                    description: 'The claims contained in the visitor JWT token',
+                                    properties: {
+                                        key: SymbolString({ name: 'key' }),
+                                        flags: SymbolObject({
+                                            name: 'flags',
+                                            properties: {
+                                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                                            },
+                                            methods: [],
+                                        }),
+                                        hello: SymbolArray({
+                                            name: 'hello',
+                                            description: 'An array of string',
+                                            items: SymbolString(),
+                                        }),
+                                        role: SymbolString({
+                                            name: 'role',
+                                            enum: ['admin', 'editor', 'reader'],
+                                        }),
+                                    },
+                                    methods: [],
+                                }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor',
+                        parentRef: undefined,
+                        childrenRefs: ['visitor.claims'],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 ? <cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'visitor',
+                            properties: {
+                                claims: SymbolObject({
+                                    name: 'claims',
+                                    description: 'The claims contained in the visitor JWT token',
+                                    properties: {
+                                        key: SymbolString({ name: 'key' }),
+                                        flags: SymbolObject({
+                                            name: 'flags',
+                                            properties: {
+                                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                                            },
+                                            methods: [],
+                                        }),
+                                        hello: SymbolArray({
+                                            name: 'hello',
+                                            description: 'An array of string',
+                                            items: SymbolString(),
+                                        }),
+                                        role: SymbolString({
+                                            name: 'role',
+                                            enum: ['admin', 'editor', 'reader'],
+                                        }),
+                                    },
+                                    methods: [],
+                                }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor',
+                        parentRef: undefined,
+                        childrenRefs: ['visitor.claims'],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 ? visit<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'visitor',
+                            properties: {
+                                claims: SymbolObject({
+                                    name: 'claims',
+                                    description: 'The claims contained in the visitor JWT token',
+                                    properties: {
+                                        key: SymbolString({ name: 'key' }),
+                                        flags: SymbolObject({
+                                            name: 'flags',
+                                            properties: {
+                                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                                            },
+                                            methods: [],
+                                        }),
+                                        hello: SymbolArray({
+                                            name: 'hello',
+                                            description: 'An array of string',
+                                            items: SymbolString(),
+                                        }),
+                                        role: SymbolString({
+                                            name: 'role',
+                                            enum: ['admin', 'editor', 'reader'],
+                                        }),
+                                    },
+                                    methods: [],
+                                }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor',
+                        parentRef: undefined,
+                        childrenRefs: ['visitor.claims'],
+                    },
+                },
+            ],
+        },
+        {
+            expressionWithCursor: 'visitor.claims.flags.FLAG1 ? visitor.claims.fl<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: SymbolObject({
+                            name: 'flags',
+                            properties: {
+                                FLAG1: SymbolBoolean({ name: 'FLAG1' }),
+                                FLAG2: SymbolBoolean({ name: 'FLAG2' }),
+                                FLAG3: SymbolBoolean({ name: 'FLAG3' }),
+                                FLAG4: SymbolBoolean({ name: 'FLAG4' }),
+                            },
+                            methods: [],
+                        }),
+                        ref: 'visitor.claims.flags',
+                        parentRef: 'visitor.claims',
+                        childrenRefs: [
+                            'visitor.claims.flags.FLAG1',
+                            'visitor.claims.flags.FLAG2',
+                            'visitor.claims.flags.FLAG3',
+                            'visitor.claims.flags.FLAG4',
+                        ],
+                    },
+                },
+            ],
+        },
+    ];
+    it.each(SCENARIOS)(
+        'should provide matching suggestion for expression with cursor: $expressionWithCursor',
+        ({ expressionWithCursor, expectedSuggestions }) => {
+            const { expression, cursorOffset } = extractCursorPosition(
+                expressionWithCursor,
+                '<cur>'
+            );
+            const { suggestions } = runtime.autocomplete(expression, cursorOffset, context);
+            expect(suggestions).toStrictEqual(expectedSuggestions);
+        }
+    );
+});
+
+function extractCursorPosition(
+    expressionWithCursor: string,
+    cursorPlaceholder: string
+): { expression: string; cursorOffset: number } {
+    const cursorOffset = expressionWithCursor.indexOf(cursorPlaceholder);
+    if (cursorOffset === -1) {
+        throw new Error(
+            `Cursor position (${cursorPlaceholder}) not found in the expression string.`
+        );
+    }
+
+    const expression = expressionWithCursor.replace(cursorPlaceholder, '');
+    return { expression, cursorOffset };
+}

packages/expr/src/__tests__/input-values.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, it } from 'bun:test';
+
+import { inferDefaultInputValuesFromObjectJSONSchema } from '../input-values';
+
+describe('inferDefaultInputValuesFromObjectJSONSchema', () => {
+    it('should infer properly the default input value based on the JSON schema of an object', () => {
+        const defaultInputValues = inferDefaultInputValuesFromObjectJSONSchema({
+            type: 'object',
+            properties: {
+                claims: {
+                    type: 'object',
+                    properties: {
+                        key: {
+                            type: 'string',
+                        },
+                        flags: {
+                            type: 'object',
+                            properties: {
+                                FLAG1: { type: 'string' },
+                                FLAG2: { type: 'string' },
+                                FLAG3: { type: 'string' },
+                            },
+                        },
+                        isAlphaUser: {
+                            type: 'boolean',
+                        },
+                        hello: {
+                            type: 'string',
+                            enum: ['enumValue1', 'enumValue2', 'enumValue3'],
+                        },
+                    },
+                },
+            },
+        });
+        expect(defaultInputValues).toMatchObject({
+            claims: {
+                key: 'default',
+                flags: {
+                    FLAG1: 'default',
+                    FLAG2: 'default',
+                    FLAG3: 'default',
+                },
+                isAlphaUser: true,
+                hello: 'enumValue1',
+            },
+        });
+    });
+});

packages/expr/src/__tests__/runtime.test.ts

@@ -0,0 +1,178 @@
+import { describe, expect, it } from 'bun:test';
+
+import { ExpressionError } from '../errors';
+import { ExpressionRuntime } from '../runtime';
+import type { Logger } from '../types';
+
+const SILENT_LOGGER: Logger = {
+    debug: () => {},
+    info: () => {},
+    error: () => {},
+};
+
+describe('ExpressionRuntime', () => {
+    const runtime = new ExpressionRuntime(SILENT_LOGGER);
+
+    describe('evaluate', () => {
+        it.each([
+            {
+                scenario: 'simple condition',
+                condition: 'isBetaUser === true',
+                inputs: { isBetaUser: false },
+                expectedResult: false,
+            },
+            {
+                scenario: 'simple condition with multiple inputs variables',
+                condition: 'useProductA && !isBetaUser',
+                inputs: {
+                    useProductA: true,
+                    isBetaUser: false,
+                },
+                expectedResult: true,
+            },
+            {
+                scenario: 'condition with objects in inputs variables',
+                condition: 'products.includes("productA") && userSegments.alpha',
+                inputs: {
+                    products: ['productA', 'productB'],
+                    userSegments: {
+                        alpha: true,
+                        beta: false,
+                    },
+                },
+                expectedResult: true,
+            },
+            {
+                scenario: 'array method',
+                condition: 'reviews.every(review => !!review.status)',
+                inputs: { reviews: [{ status: 'approved' }, { status: 'approved' }] },
+                expectedResult: true,
+            },
+            {
+                scenario: 'array every',
+                condition: 'reviews.every(review => review.status === "approved")',
+                inputs: { reviews: [{ status: 'approved' }, { status: 'approved' }] },
+                expectedResult: true,
+            },
+            {
+                scenario: 'array map',
+                condition: '[1, 2, 3].map(n => n * x)',
+                inputs: { x: 2 },
+                expectedResult: [2, 4, 6],
+            },
+        ])(
+            'should properly evaluate/safeEvaluate a valid conditional expression: $scenario',
+            ({ condition, inputs, expectedResult }) => {
+                expect(runtime.evaluate(condition, inputs)).toEqual(expectedResult);
+                expect(runtime.safeEvaluate(condition, inputs).value).toEqual(expectedResult);
+            }
+        );
+
+        const INVALID_EXPRESSSIONS = [
+            {
+                scenario: 'invalid syntax',
+                condition: 't}=d',
+                inputs: {},
+            },
+            {
+                scenario: 'non conditional expression',
+                condition: 'const a = 1;',
+                inputs: {},
+            },
+            {
+                scenario: 'unsafe expression',
+                condition: 'while (1) {}',
+                inputs: {},
+            },
+            {
+                scenario: 'unsafe expression',
+                condition: '[1, 2, 3].map(() => { while (1) {}})',
+                inputs: {},
+            },
+        ];
+
+        it.each(INVALID_EXPRESSSIONS)(
+            'should return an object with the error for non conditional expression or syntax errors when using safeEvaluate is on (default): $scenario',
+            ({ condition, inputs }) => {
+                const result = runtime.safeEvaluate(condition, inputs);
+                expect(result.value).toBeUndefined();
+                expect(result.error instanceof ExpressionError).toBe(true);
+            }
+        );
+
+        it.each(INVALID_EXPRESSSIONS)(
+            'should throw an error when using evaluate with invalid expressions',
+            ({ condition, inputs }) => {
+                expect(() => runtime.evaluate(condition, inputs)).toThrowError(ExpressionError);
+            }
+        );
+    });
+
+    describe('parse', () => {
+        it('should produce a valid ESTree compatible AST node for conditional expressions', () => {
+            const ast = runtime.parse('isBetaUser === true');
+
+            expect(ast.result).toEqual({
+                type: 'BinaryExpression',
+                start: 0,
+                end: 19,
+                loc: { start: { line: 1, column: 0 }, end: { line: 1, column: 19 } },
+                left: {
+                    type: 'Identifier',
+                    start: 0,
+                    end: 10,
+                    loc: { start: { line: 1, column: 0 }, end: { line: 1, column: 10 } },
+                    name: 'isBetaUser',
+                },
+                operator: '===',
+                right: {
+                    type: 'Literal',
+                    start: 15,
+                    end: 19,
+                    loc: { start: { line: 1, column: 15 }, end: { line: 1, column: 19 } },
+                    value: true,
+                    raw: 'true',
+                },
+            });
+        });
+
+        it.each([
+            {
+                scenario: 'invalid syntax',
+                condition: 't}=d',
+            },
+            {
+                scenario: 'non conditional expression',
+                condition: 'const a = 1;',
+            },
+        ])(
+            'should throw an error for non conditional expressions or syntax errors: $scenario',
+            ({ condition }) => {
+                expect(() => runtime.parse(condition)).toThrowError(ExpressionError);
+            }
+        );
+    });
+
+    describe.skip('generate', () => {
+        it.each([
+            {
+                scenario: 'simple condition',
+                condition: 'isBetaUser === true',
+            },
+            {
+                scenario: 'simple condition with multiple inputs variables',
+                condition: 'useProductA && !isBetaUser',
+            },
+            {
+                scenario: 'condition with objects in inputs variables',
+                condition: 'products.includes("productA") && userSegments.alpha',
+            },
+        ])(
+            'should produce the original expression using an AST node produced by parse: $scenario',
+            ({ condition }) => {
+                const { result } = runtime.parse(condition);
+                expect(runtime.generate(result)).toStrictEqual(condition);
+            }
+        );
+    });
+});

packages/expr/src/__tests__/template.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, it } from 'bun:test';
+
+import { ExpressionRuntime, parseTemplate } from '../';
+
+describe('template expressions', () => {
+    it('should parse template into parts', () => {
+        const parts = parseTemplate('Hello {{ user.name }}!');
+        expect(parts).toEqual([
+            { type: 'text', value: 'Hello ', start: 0, end: 6 },
+            { type: 'expression', value: 'user.name', start: 8, end: 19 },
+            { type: 'text', value: '!', start: 21, end: 22 },
+        ]);
+    });
+
+    it('should parse template starting with an expression', () => {
+        const parts = parseTemplate('{{ user.name }} is cool');
+        expect(parts).toEqual([
+            { type: 'expression', value: 'user.name', start: 2, end: 13 },
+            { type: 'text', value: ' is cool', start: 15, end: 23 },
+        ]);
+    });
+
+    it('should parse template without expressions', () => {
+        const parts = parseTemplate('Hello world');
+        expect(parts).toEqual([{ type: 'text', value: 'Hello world', start: 0, end: 11 }]);
+    });
+
+    it('should evaluate template', () => {
+        const runtime = new ExpressionRuntime();
+        const result = runtime.evaluateTemplate('Hello {{ user.name }}!', {
+            user: { name: 'John' },
+        });
+        expect(result).toBe('Hello John!');
+    });
+});

packages/expr/src/autocomplete.ts

@@ -0,0 +1,568 @@
+import type {
+    Node as AcornNode,
+    AnyNode,
+    BinaryExpression,
+    Expression,
+    Identifier,
+    Literal,
+    MemberExpression,
+    PrivateIdentifier,
+    Super,
+} from 'acorn';
+import { isDummy } from 'acorn-loose';
+import * as walk from 'acorn-walk';
+
+import assertNever from 'assert-never';
+
+import { type ExtractSymbolDef, SymbolType, SymbolsTable } from './symbols';
+import {
+    type AutocompleteLiteralValueSuggestion,
+    type AutocompleteOperatorSuggestion,
+    type AutocompleteSuggestions,
+    type AutocompleteSymbolSuggestion,
+    type DirectLiteralValueSuggestion,
+    type ExpressionParserResult,
+    type Logger,
+    SUPPORTED_BINARY_OPERATORS,
+    SUPPORTED_CONDITIONAL_OPERATORS,
+    SUPPORTED_LOGICAL_OPERATORS,
+} from './types';
+
+interface ExpressionParser {
+    parse(expr: string, options: { loose?: boolean }): ExpressionParserResult;
+}
+
+export class AutoComplete {
+    #parser: ExpressionParser;
+    #logger: Logger;
+
+    constructor(parser: ExpressionParser, logger: Logger = console) {
+        this.#parser = parser;
+        this.#logger = logger;
+    }
+
+    /**
+     * Generates autocomplete suggestions based on the input expression and cursor offset position.
+     */
+    public getSuggestions(
+        expr: string,
+        cursorOffset: number,
+        context: SymbolsTable
+    ): AutocompleteSuggestions {
+        if (!expr.length) {
+            return [];
+        }
+
+        try {
+            const { result, invalidNodes } = this.#parser.parse(expr, { loose: true });
+
+            // Locate the node at the cursor position.
+            const nodeAtCursorFound = walk.findNodeAround(result, cursorOffset, (_type, node) =>
+                isNodeAtCursor(node, cursorOffset)
+            );
+
+            if (!nodeAtCursorFound) {
+                // When we can't find one we might be in the boundary of the program/expression.
+                // We could possibly be in a whitespace at the end of the expression or in a situation where the parsed
+                // tree may contain 2 top level ExpressionStatement (second one returned as invalid node by the parser).
+                //
+                // In this case we want to provide operators as suggestions and refine the search of the "cursor" node to either:
+                //   - using the end position of the whole expression AST (e.g white space at the very end of the expression string)
+                //   - or using the second top level ExpressionStatement node found by the parser as the cursor is at the end of that node.
+                if (cursorOffset > result.end) {
+                    const ast = invalidNodes.length > 0 ? invalidNodes[0]?.expression : result;
+
+                    if (!ast) {
+                        return [];
+                    }
+
+                    const lastNodeFound = walk.findNodeAround(ast, ast.end, (_type, node) =>
+                        isNodeAtCursor(node, ast.end)
+                    );
+                    if (!lastNodeFound) {
+                        return [];
+                    }
+                    const { node } = lastNodeFound;
+
+                    if (!isAnyNode(node)) {
+                        throw Error(`Unexpected node type ${node.type}`);
+                    }
+
+                    return this.getOperatorSuggestionsForNode(ast, node, result.end, context);
+                }
+                return [];
+            }
+
+            const { node } = nodeAtCursorFound;
+
+            if (!isAnyNode(node)) {
+                throw Error(`Unexpected node type ${node.type}`);
+            }
+
+            return this.getSuggestionsForNode(result, node, expr, cursorOffset, context);
+        } catch (error) {
+            this.#logger.error('Error while computing autocomplete suggestions', error);
+            return [];
+        }
+    }
+
+    /**
+     * Provides autocomplete suggestions for a specific node in the AST.
+     */
+    private getSuggestionsForNode(
+        ast: Expression,
+        node: AnyNode,
+        expr: string,
+        cursorOffset: number,
+        context: SymbolsTable
+    ): AutocompleteSuggestions {
+        // When the node is an identifier look up the parent to get more context for the suggestions.
+        let inferNode: AnyNode = node;
+        if (node.type === 'Identifier' || node.type === 'Literal') {
+            const parent = findParentNode(node, ast);
+            inferNode =
+                parent &&
+                !['ExpressionStatement', 'LogicalExpression', 'ConditionalExpression'].includes(
+                    parent.type
+                )
+                    ? parent
+                    : node;
+        }
+
+        switch (inferNode.type) {
+            case 'Identifier':
+            case 'MemberExpression': {
+                const pathParts = this.getSymbolsPathPartsForMemberExpressionNode(
+                    inferNode,
+                    cursorOffset
+                );
+
+                // Fetch suggestions from the symbol table
+                const candidatesKeys = context.getMatchingSymbolsKeys(pathParts);
+
+                const suggestions: AutocompleteSymbolSuggestion[] = [];
+                for (const candidate of candidatesKeys) {
+                    const symbolInfo = context.getSymbolInfo(candidate);
+                    if (symbolInfo) {
+                        suggestions.push({ type: 'symbol', symbol: symbolInfo });
+                    }
+                }
+
+                if (suggestions.length === 1) {
+                    const lastPathSegment = pathParts.at(-1)?.replace(/\*$/, '');
+
+                    // Return no suggestion when the only match is an exact match of the
+                    // typed token.
+                    return lastPathSegment !== suggestions[0]?.symbol.definition.name
+                        ? suggestions
+                        : [];
+                }
+
+                return suggestions;
+            }
+            case 'AssignmentExpression':
+            case 'UnaryExpression': {
+                // Provide suggestions for binary or logical operators based on the parsed operator
+                // of the partial expression (e.g suggest "==" when typing "=" (parsed as AssignmentExpression)).
+                return this.getOperatorSuggestionsForNode(ast, inferNode, cursorOffset, context);
+            }
+            case 'BinaryExpression': {
+                const { left, right } = inferNode;
+
+                const isOperatorBinaryOp = SUPPORTED_BINARY_OPERATORS.some(
+                    (op) => op.operator === inferNode.operator
+                );
+
+                const operatorIndex = expr.indexOf(inferNode.operator, left.end);
+                const operatorOffset = operatorIndex + inferNode.operator.length;
+                const isCursorAfterOperator = cursorOffset > operatorOffset;
+
+                const shouldSuggestValues =
+                    isCursorAfterOperator &&
+                    isOperatorBinaryOp &&
+                    isNodeAtCursor(right, cursorOffset);
+
+                if (shouldSuggestValues) {
+                    return this.getLiteralValueSuggestionsForNode(inferNode, cursorOffset, context);
+                }
+
+                // Provide suggestions for binary operators based on the parsed operator
+                return this.getOperatorSuggestionsForNode(ast, inferNode, cursorOffset, context);
+            }
+            case 'ConditionalExpression': {
+                const { consequent, alternate } = inferNode;
+
+                if (isNodeAtCursor(consequent, cursorOffset)) {
+                    return this.getSuggestionsForNode(ast, consequent, expr, cursorOffset, context);
+                }
+
+                if (isNodeAtCursor(alternate, cursorOffset)) {
+                    return this.getSuggestionsForNode(ast, alternate, expr, cursorOffset, context);
+                }
+            }
+        }
+
+        return [];
+    }
+
+    /**
+     * Return a path corresponding to the MemberExpression node that can be used to lookup matching symbols in the symbol table.
+     */
+    private getSymbolsPathPartsForMemberExpressionNode(
+        node: MemberExpression | Identifier,
+        cursorOffset: number,
+        options?: { withWildcardMatches: boolean }
+    ): string[] {
+        const withWildcardMatches = options?.withWildcardMatches ?? true;
+        const pathParts: string[] = [];
+
+        switch (node.type) {
+            case 'MemberExpression':
+                {
+                    const memberProperty = node.property;
+
+                    // Only support identifier or literal expressions as member properties.
+                    if (!isSupportedMemberProperty(memberProperty)) {
+                        return [];
+                    }
+
+                    // Push the path part corresponding to the member property (e.g b in a.b or a['b'])
+                    const propertyPathPart = this.getSymbolsPathPartFromMemberProperty(
+                        memberProperty,
+                        cursorOffset
+                    );
+
+                    if (propertyPathPart) {
+                        pathParts.push(
+                            withWildcardMatches ? `${propertyPathPart}*` : propertyPathPart
+                        );
+                    }
+
+                    // Go through the parent(s) in the chain and add their path parts as well
+                    let parent: Expression | Super | undefined = node.object;
+                    while (parent) {
+                        const parentProperty = 'property' in parent ? parent.property : parent;
+
+                        // Only support identifier or literal expressions as parent property.
+                        const parentPropertyPathPart = isSupportedMemberProperty(parentProperty)
+                            ? this.getSymbolsPathPartFromMemberProperty(
+                                  parentProperty,
+                                  cursorOffset
+                              )
+                            : undefined;
+
+                        if (parentPropertyPathPart) {
+                            pathParts.unshift(parentPropertyPathPart);
+                        }
+
+                        parent = 'object' in parent ? parent.object : undefined;
+                    }
+                }
+                break;
+            case 'Identifier': {
+                const propertyPathPart = this.getSymbolsPathPartFromMemberProperty(
+                    node,
+                    cursorOffset
+                );
+                if (propertyPathPart) {
+                    pathParts.push(withWildcardMatches ? `${propertyPathPart}*` : propertyPathPart);
+                }
+                break;
+            }
+            default:
+                assertNever(node);
+        }
+
+        return pathParts;
+    }
+
+    /**
+     * Return a part of a symbol path corresponding to a MemberExpression node property.
+     */
+    private getSymbolsPathPartFromMemberProperty(
+        node: Identifier | Literal,
+        cursorOffset: number
+    ): string {
+        switch (node.type) {
+            case 'Identifier': {
+                if (isDummy(node)) {
+                    return '*';
+                }
+
+                return isNodeAtCursor(node, cursorOffset)
+                    ? node.name.slice(0, cursorOffset)
+                    : node.name;
+            }
+            case 'Literal': {
+                if (isDummy(node) || !node.value) {
+                    return '*';
+                }
+                const value = String(node.value);
+                return isNodeAtCursor(node, cursorOffset) ? value.slice(0, cursorOffset) : value;
+            }
+            default:
+                assertNever(node);
+        }
+    }
+
+    /**
+     * Provides autocomplete literal value suggestions for a specific node in the AST.
+     */
+    private getLiteralValueSuggestionsForNode(
+        node: BinaryExpression,
+        cursorOffset: number,
+        context: SymbolsTable
+    ): Array<AutocompleteLiteralValueSuggestion> {
+        const { left, right } = node;
+
+        if (left.type !== 'MemberExpression' && left.type !== 'Identifier') {
+            return [];
+        }
+
+        if (right.type !== 'Identifier' && right.type !== 'Literal') {
+            return [];
+        }
+
+        const leftSymbolPath = this.getSymbolsPathPartsForMemberExpressionNode(left, cursorOffset, {
+            withWildcardMatches: false,
+        });
+
+        const isLeftComputedMember = left.type === 'MemberExpression' && left.computed;
+        const leftSymbolInfo = context.getSymbolInfo(
+            isLeftComputedMember ? leftSymbolPath.slice(0, -1) : leftSymbolPath
+        );
+
+        if (!leftSymbolInfo) {
+            return [];
+        }
+
+        switch (leftSymbolInfo.definition.type) {
+            case SymbolType.Boolean: {
+                const suggestions: DirectLiteralValueSuggestion[] = [
+                    {
+                        type: 'literal-value',
+                        value: { kind: 'direct', type: SymbolType.Boolean, data: true },
+                    },
+                    {
+                        type: 'literal-value',
+                        value: { kind: 'direct', type: SymbolType.Boolean, data: false },
+                    },
+                ];
+
+                return isDummy(right)
+                    ? suggestions
+                    : suggestions.filter((literalValue) => {
+                          const literalValueString = String(literalValue.value.data);
+                          const rightNodeValue =
+                              right.type === 'Identifier' ? right.name : (right.raw ?? '');
+                          return (
+                              literalValueString !== rightNodeValue &&
+                              literalValueString.startsWith(rightNodeValue)
+                          );
+                      });
+            }
+            case SymbolType.String: {
+                if (!leftSymbolInfo.definition.enum) {
+                    return [];
+                }
+
+                const rightNodeValue = (() => {
+                    if (right.type === 'Identifier') {
+                        return right.name;
+                    }
+
+                    const nodeValue = right.raw ?? '';
+                    if (/^(['"])(.*)\1$/.test(nodeValue)) {
+                        return null;
+                    }
+
+                    return nodeValue.replaceAll(/["']/g, '');
+                })();
+
+                if (rightNodeValue === null) {
+                    return [];
+                }
+
+                const suggestions = isDummy(right)
+                    ? leftSymbolInfo.definition.enum
+                    : leftSymbolInfo.definition.enum.filter((enumValue) =>
+                          enumValue.startsWith(rightNodeValue)
+                      );
+
+                return suggestions.map((value) => ({
+                    type: 'literal-value',
+                    value: {
+                        kind: 'direct',
+                        type: SymbolType.String,
+                        data: value,
+                    },
+                }));
+            }
+            case SymbolType.Array: {
+                // Only return a literal in array value suggestion when the left hand side of the binary expression
+                // is computed, e.g myArray[1]
+                return isLeftComputedMember
+                    ? [
+                          {
+                              type: 'literal-value',
+                              value: {
+                                  kind: 'in-array',
+                                  srcSymbol: leftSymbolInfo.definition,
+                                  matchedLiteralString: !isDummy(right)
+                                      ? right.type === 'Identifier'
+                                          ? right.name
+                                          : (right.raw ?? '')
+                                      : '',
+                              },
+                          },
+                      ]
+                    : [];
+            }
+            default:
+                return [];
+        }
+    }
+
+    /**
+     * Provides autocomplete operator suggestions for a specific node in the AST.
+     */
+    private getOperatorSuggestionsForNode(
+        ast: Expression,
+        node: AnyNode,
+        cursorOffset: number,
+        context: SymbolsTable
+    ): Array<AutocompleteOperatorSuggestion> {
+        if (node.type === 'Literal') {
+            const parent = findParentNode(node, ast);
+
+            if (parent?.type === 'BinaryExpression') {
+                return [...SUPPORTED_LOGICAL_OPERATORS, ...SUPPORTED_CONDITIONAL_OPERATORS].map(
+                    (op) => ({
+                        type: 'operator',
+                        ...op,
+                    })
+                );
+            }
+
+            const literalSymbol = SymbolsTable.inferSymbolFromValue(node.raw);
+            return this.getOperatorSuggestionsForSymbol(literalSymbol);
+        }
+
+        // When the node is an identifier look the parent to get more context for the suggestions
+        let inferNode: AnyNode = node;
+        if (node.type === 'Identifier') {
+            const parent = findParentNode(node, ast);
+            inferNode = parent && parent.type !== 'ExpressionStatement' ? parent : node;
+        }
+
+        switch (inferNode.type) {
+            case 'MemberExpression': {
+                const pathParts = this.getSymbolsPathPartsForMemberExpressionNode(
+                    inferNode,
+                    cursorOffset,
+                    {
+                        withWildcardMatches: false,
+                    }
+                );
+                const symbolInfo = context.getSymbolInfo(pathParts);
+                return symbolInfo
+                    ? this.getOperatorSuggestionsForSymbol(symbolInfo.definition)
+                    : [];
+            }
+            case 'AssignmentExpression':
+            case 'BinaryExpression':
+            case 'UnaryExpression': {
+                // Starting to write a binary/logical operator so suggest operator matching the already
+                // typed character as operator.
+                const operator = inferNode.operator;
+                return (
+                    [...SUPPORTED_BINARY_OPERATORS, ...SUPPORTED_LOGICAL_OPERATORS]
+                        .filter((op) => op.operator.startsWith(operator))
+                        // No need to include the operator that match exactly
+                        .filter((op) => op.operator !== operator)
+                        .map((op) => ({
+                            type: 'operator',
+                            ...op,
+                        }))
+                );
+            }
+            default:
+                return [];
+        }
+    }
+
+    /**
+     * Provides autocomplete operator suggestions based on the type of a symbol.
+     */
+    private getOperatorSuggestionsForSymbol(
+        symbol: ExtractSymbolDef<SymbolType>
+    ): Array<AutocompleteOperatorSuggestion> {
+        switch (symbol.type) {
+            case SymbolType.Number:
+            case SymbolType.Boolean:
+            case SymbolType.Null:
+            case SymbolType.Undefined:
+            case SymbolType.Object:
+            case SymbolType.Array: {
+                const equalityOps = SUPPORTED_BINARY_OPERATORS.slice(0, 4);
+                const finalSuggestions =
+                    symbol.type === SymbolType.Boolean
+                        ? [
+                              ...equalityOps,
+                              ...SUPPORTED_LOGICAL_OPERATORS,
+                              ...SUPPORTED_CONDITIONAL_OPERATORS,
+                          ]
+                        : equalityOps;
+                return finalSuggestions.map((op) => ({
+                    type: 'operator',
+                    ...op,
+                }));
+            }
+            case SymbolType.String:
+                return SUPPORTED_BINARY_OPERATORS.map((op) => ({
+                    type: 'operator',
+                    ...op,
+                }));
+            case SymbolType.Function:
+                return this.getOperatorSuggestionsForSymbol(symbol.returns);
+            case SymbolType.Union: {
+                return symbol.members.reduce<Array<AutocompleteOperatorSuggestion>>((prev, cur) => {
+                    prev.push(...this.getOperatorSuggestionsForSymbol(cur));
+                    return prev;
+                }, []);
+            }
+            default:
+                assertNever(symbol);
+        }
+    }
+}
+
+/**
+ * Finds the parent of child node in the provided AST.
+ */
+function findParentNode(child: AnyNode, ast: Expression): AnyNode | undefined {
+    let foundParent: AnyNode | undefined;
+
+    walk.ancestor(ast, {
+        [child.type]: (node: AcornNode, _state: undefined, ancestors: AnyNode[]) => {
+            if (node.start === child.start && node.end === child.end) {
+                // The parent is the second last ancestor in the stack (last one is the actual node)
+                foundParent = ancestors[ancestors.length - 2];
+            }
+        },
+    });
+
+    return foundParent;
+}
+
+function isSupportedMemberProperty(node: Expression | PrivateIdentifier | Super) {
+    return node.type === 'Identifier' || node.type === 'Literal';
+}
+
+function isNodeAtCursor(node: AcornNode, cursorOffset: number) {
+    return cursorOffset >= node.start && cursorOffset <= node.end;
+}
+
+function isAnyNode(node: AcornNode): node is AnyNode {
+    return 'type' in node;
+}

packages/expr/src/errors.ts

@@ -0,0 +1,24 @@
+import type { Position, Token } from 'acorn';
+
+export class ExpressionError extends Error {
+    /**
+     * The location of the error in the parsed expression.
+     */
+    public location?: Position | null;
+
+    /**
+     * The expression token with the error
+     */
+    public token?: Token;
+
+    constructor(message: string, loc?: Position | null, token?: Token) {
+        super(message);
+
+        if (Error.captureStackTrace) {
+            Error.captureStackTrace(this, ExpressionError);
+        }
+        this.name = 'ExpressionError';
+        this.location = loc;
+        this.token = token;
+    }
+}

packages/expr/src/index.ts

@@ -0,0 +1,7 @@
+export * from './errors';
+export * from './input-values';
+export * from './runtime';
+export * from './symbols';
+export * from './template';
+export * from './types';
+export * from './utils';

packages/expr/src/input-values.ts

@@ -0,0 +1,77 @@
+import type { JSONSchema7 } from 'json-schema';
+import { filterOutNullable } from './utils';
+
+type InputValuesType =
+    | null
+    | string
+    | number
+    | boolean
+    | { [key: string]: InputValuesType }
+    | InputValuesType[];
+
+/**
+ * Infers a default inputValues object based on the JSON schema of an object.
+ */
+export function inferDefaultInputValuesFromObjectJSONSchema(
+    schema: JSONSchema7
+): Record<string, InputValuesType> {
+    if (schema.type !== 'object' || !schema.properties) {
+        throw new Error(`Expected schema of object to be provided: ${schema.type}`);
+    }
+
+    const result: Record<string, InputValuesType> = {};
+
+    for (const [key, propertySchema] of Object.entries(schema.properties)) {
+        if (typeof propertySchema === 'boolean') {
+            continue;
+        }
+
+        result[key] = inferDefaultInputValueFromJSONSchema(propertySchema);
+    }
+
+    return result;
+}
+
+function inferDefaultInputValueFromJSONSchema(schema: JSONSchema7): InputValuesType {
+    switch (schema.type) {
+        case 'object':
+            return inferDefaultInputValuesFromObjectJSONSchema(schema);
+        case 'array': {
+            if (schema.items && Array.isArray(schema.items)) {
+                return schema.items.map((itemSchema) => {
+                    if (typeof itemSchema === 'boolean') {
+                        return false;
+                    }
+                    return inferDefaultInputValueFromJSONSchema(itemSchema);
+                });
+            }
+            return [];
+        }
+        case 'string':
+        case 'number':
+        case 'integer':
+        case 'boolean':
+        case 'null':
+            return inferDefaultInputValueFromPrimitive(schema);
+        default:
+            throw new Error(`Unsupported schema type: ${schema.type}`);
+    }
+}
+
+function inferDefaultInputValueFromPrimitive(schema: JSONSchema7): InputValuesType {
+    switch (schema.type) {
+        case 'boolean':
+            return true;
+        case 'number':
+        case 'integer':
+            return 1234;
+        case 'string': {
+            const enumValues = schema.enum?.filter(filterOutNullable);
+            return enumValues?.[0] ?? 'default';
+        }
+        case 'null':
+            return null;
+        default:
+            throw new Error(`Unsupported schema type: ${schema.type}`);
+    }
+}

packages/expr/src/runtime.ts

@@ -0,0 +1,289 @@
+import {
+    type Options as AcornOptions,
+    type Expression,
+    type ExpressionStatement,
+    type Position,
+    type Program,
+    type Token,
+    parse,
+    tokenizer,
+} from 'acorn';
+import { parse as parseLoose } from 'acorn-loose';
+import escodegen from 'escodegen';
+import evalESTreeExpr from 'eval-estree-expression';
+const { evaluate } = evalESTreeExpr;
+
+import { AutoComplete } from './autocomplete';
+import { ExpressionError } from './errors';
+import type { SymbolsTable } from './symbols';
+import type { TemplatePart } from './template';
+import { parseTemplate as parseTemplateParts } from './template';
+import type { ExpressionAutocompleteResults, ExpressionParserResult, Logger } from './types';
+import { formatExpressionResult } from './utils';
+
+export class ExpressionRuntime {
+    #parserOptions: AcornOptions;
+    #autocompleter: AutoComplete;
+    #logger: Logger;
+
+    constructor(logger: Logger = console) {
+        this.#parserOptions = {
+            ecmaVersion: 'latest',
+            sourceType: 'script',
+            allowHashBang: false,
+            locations: true,
+        };
+        this.#autocompleter = new AutoComplete(this, logger);
+        this.#logger = logger;
+    }
+
+    /**
+     * Evaluates an expression based on the given inputs/context.
+     */
+    public evaluate(expr: string, inputs: object): unknown {
+        try {
+            const parsed = this.parse(expr);
+
+            if (parsed.invalidNodes.length > 0) {
+                throw new ExpressionError('Invalid nodes found when parsing');
+            }
+
+            return evaluate.sync<Expression>(parsed.result, inputs, {
+                functions: true,
+                withMembers: true,
+                generate: escodegen.generate,
+            });
+        } catch (error) {
+            throw error instanceof Error
+                ? new ExpressionError(error.message)
+                : new ExpressionError('Unexpected error');
+        }
+    }
+
+    /**
+     * Evaluates an expression safely by returning the error instead of throwing when invalid.
+     */
+    public safeEvaluate(
+        expr: string,
+        inputs: object
+    ): { value: unknown; error?: undefined } | { value?: undefined; error: ExpressionError } {
+        try {
+            const value = this.evaluate(expr, inputs);
+            return {
+                value,
+            };
+        } catch (error) {
+            this.#logger.error(`Error while evaluating expression ${expr}`, error);
+
+            if (error instanceof ExpressionError) {
+                return {
+                    value: undefined,
+                    error,
+                };
+            }
+
+            return {
+                value: undefined,
+                error:
+                    error instanceof Error
+                        ? new ExpressionError(error.message)
+                        : new ExpressionError('Unexpected error'),
+            };
+        }
+    }
+
+    /**
+     * Evaluates a condition safely to a boolean.
+     */
+    public evaluateBoolean(expr: string, inputs: object): boolean {
+        if (expr.trim().length === 0) {
+            return true;
+        }
+
+        const evalResult = this.safeEvaluate(expr, inputs);
+
+        if (typeof evalResult.error !== 'undefined') {
+            return false;
+        }
+
+        return Boolean(evalResult.value);
+    }
+
+    /**
+     * Evaluates an array of conditions as a single logical expression.
+     * The function treats the conditions as if they were joined by an AND operator,
+     * meaning the evaluation returns `true` only if all conditions are truthy.
+     */
+    public evaluateBooleanAll(expressions: string[], inputs: object): boolean {
+        if (expressions.length === 0) {
+            return true;
+        }
+
+        return expressions.every((expression) => this.evaluateBoolean(expression, inputs));
+    }
+
+    /**
+     * Parse a template and validate all embedded expressions.
+     */
+    public parseTemplate(template: string): { parts: TemplatePart[]; errors: ExpressionError[] } {
+        const parts = parseTemplateParts(template);
+        const errors: ExpressionError[] = [];
+
+        for (const part of parts) {
+            if (part.type === 'expression') {
+                try {
+                    const { invalidNodes } = this.parse(part.value);
+                    if (invalidNodes.length > 0) {
+                        errors.push(new ExpressionError('Invalid expression'));
+                    }
+                } catch (error) {
+                    errors.push(error as ExpressionError);
+                }
+            }
+        }
+
+        return { parts, errors };
+    }
+
+    /**
+     * Evaluate a template string containing `{{ expression }}` placeholders.
+     */
+    public evaluateTemplate(template: string, inputs: object): string {
+        const { parts } = this.parseTemplate(template);
+
+        return parts
+            .map((part) => {
+                if (part.type === 'text') {
+                    return part.value;
+                }
+                const result = this.evaluate(part.value, inputs);
+                return formatExpressionResult(result, '');
+            })
+            .join('');
+    }
+
+    /**
+     * Parses a binary expression and returns an @ExpressionParserResult.
+     */
+    public parse(
+        expr: string,
+        options: { loose?: boolean } = {
+            loose: false,
+        }
+    ): ExpressionParserResult {
+        try {
+            const ast = options.loose
+                ? parseLoose(expr, { ...this.#parserOptions })
+                : parse(expr, { ...this.#parserOptions });
+
+            if (!ast.body || ast.body.length === 0) {
+                throw new ExpressionError('Empty or invalid expression');
+            }
+
+            // Extract the first expression statement that we find
+            const firstExprIndex = ast.body.findIndex((node) => isParsedExpressionStatement(node));
+            const [statement] = ast.body.splice(firstExprIndex, 1);
+
+            if (!statement || !isParsedExpressionStatement(statement)) {
+                throw new ExpressionError('Empty or invalid expression');
+            }
+
+            // Return information on the other nodes as invalid nodes
+            const invalidNodes = ast.body.filter(filterOutModuleDeclarationStatement);
+
+            return {
+                result: statement.expression,
+                invalidNodes,
+            };
+        } catch (error) {
+            if (error instanceof SyntaxError) {
+                throw createExpressionErrorFromSyntaxError(expr, error);
+            }
+            if (error instanceof ExpressionError) {
+                throw error;
+            }
+            throw new ExpressionError('Unexpected error');
+        }
+    }
+
+    /**
+     * Provides autocomplete suggestions for the given expression at the provided cursor offset.
+     */
+    public autocomplete(
+        expr: string,
+        cursorOffset: number,
+        context: SymbolsTable
+    ): ExpressionAutocompleteResults {
+        const suggestions = this.#autocompleter.getSuggestions(expr, cursorOffset, context);
+
+        return { suggestions };
+    }
+
+    public generate(_node: Expression): string {
+        throw new Error('Not yet implemented');
+    }
+}
+
+function createExpressionErrorFromSyntaxError(
+    code: string,
+    error: SyntaxError & { loc?: Position }
+): ExpressionError {
+    const loc = error.loc;
+
+    if (!loc) {
+        return new ExpressionError(error.message);
+    }
+
+    const errorMessage = `${error.message.replace(/\s*\(\d+:\d+\)$/, '')} at ${code.split('\n').length > 1 ? `line ${loc.line}, ` : ''}char ${loc.column}`;
+    const token = getTokenAtLoc(code, loc);
+
+    if (!token) {
+        return new ExpressionError(errorMessage, loc);
+    }
+
+    return new ExpressionError(errorMessage, loc, token);
+}
+function getTokenAtLoc(code: string, errorLoc: Position): Token | undefined {
+    const tokens = tokenizer(code, {
+        ecmaVersion: 'latest',
+        locations: true,
+    });
+
+    try {
+        for (const token of tokens) {
+            if (!token.loc) {
+                continue;
+            }
+
+            const { start, end } = token.loc;
+
+            const onSameLine = errorLoc.line === start.line;
+            const inColumnRange = errorLoc.column >= start.column && errorLoc.column < end.column;
+
+            if (onSameLine && inColumnRange) {
+                return token;
+            }
+        }
+    } catch (_error) {
+        return undefined;
+    }
+
+    return undefined;
+}
+
+function isParsedExpressionStatement(
+    statement: Program['body'][number]
+): statement is ExpressionStatement {
+    return statement.type === 'ExpressionStatement';
+}
+
+export function filterOutModuleDeclarationStatement(
+    statement: Program['body'][number]
+): statement is ExpressionStatement {
+    return ![
+        'ImportDeclaration',
+        'ExportNamedDeclaration',
+        'ExportDefaultDeclaration',
+        'ExportAllDeclaration',
+    ].includes(statement.type);
+}

packages/expr/src/symbols/__tests__/symbols.test.ts

@@ -0,0 +1,497 @@
+import { describe, expect, it } from 'bun:test';
+
+import { SymbolArray, SymbolObject, SymbolString } from '../symbols';
+import { SymbolsTable } from '../symbols-table';
+import type { SymbolType } from '../types';
+
+describe('ExpressionRuntime', () => {
+    const initialSymbols = {
+        visitor: SymbolObject({
+            name: 'visitor',
+            properties: {
+                claims: SymbolObject({
+                    name: 'claims',
+                    description: 'The claims contained in the visitor JWT token',
+                    properties: {
+                        key: SymbolString({ name: 'key' }),
+                        flags: SymbolObject({
+                            name: 'flags',
+                            properties: {
+                                FLAG1: SymbolString({ name: 'FLAG1' }),
+                                FLAG2: SymbolString({ name: 'FLAG2' }),
+                                FLAG3: SymbolString({ name: 'FLAG3' }),
+                            },
+                            methods: [],
+                        }),
+                        hello: SymbolArray({
+                            name: 'hello',
+                            description: 'An array of string',
+                            items: SymbolString(),
+                        }),
+                    },
+                    methods: [],
+                }),
+            },
+            methods: [],
+        }),
+    };
+    describe('addSymbols', () => {
+        it('should the symbols matching the provided object to the table', () => {
+            const symbolsTable = new SymbolsTable(initialSymbols);
+
+            expect(symbolsTable.getSymbolInfo(['visitor'])).toMatchObject({
+                definition: {
+                    type: 'object',
+                    name: 'visitor',
+                    properties: {
+                        claims: {
+                            type: 'object',
+                            name: 'claims',
+                            description: 'The claims contained in the visitor JWT token',
+                            properties: {
+                                key: {
+                                    type: 'string',
+                                    name: 'key',
+                                },
+                                flags: {
+                                    type: 'object',
+                                    name: 'flags',
+                                    properties: {
+                                        FLAG1: {
+                                            type: 'string',
+                                            name: 'FLAG1',
+                                        },
+                                        FLAG2: {
+                                            type: 'string',
+                                            name: 'FLAG2',
+                                        },
+                                        FLAG3: {
+                                            type: 'string',
+                                            name: 'FLAG3',
+                                        },
+                                    },
+                                    methods: [],
+                                },
+                                hello: {
+                                    type: 'array',
+                                    name: 'hello',
+                                    description: 'An array of string',
+                                    items: {
+                                        type: 'string',
+                                    },
+                                },
+                            },
+                            methods: [],
+                        },
+                    },
+                    methods: [],
+                },
+                ref: 'visitor',
+                childrenRefs: ['visitor.claims'],
+            });
+
+            symbolsTable.addSymbols({
+                space: SymbolObject({
+                    name: 'space',
+                    properties: {
+                        id: SymbolString({ name: 'id' }),
+                        title: SymbolString({ name: 'title' }),
+                    },
+                    methods: [],
+                }),
+            });
+
+            expect(symbolsTable.getSymbolInfo(['space'])).toMatchObject({
+                definition: {
+                    type: 'object',
+                    name: 'space',
+                    properties: {
+                        id: {
+                            type: 'string',
+                            name: 'id',
+                        },
+                        title: {
+                            type: 'string',
+                            name: 'title',
+                        },
+                    },
+                    methods: [],
+                },
+                ref: 'space',
+                childrenRefs: ['space.id', 'space.title'],
+            });
+        });
+    });
+
+    describe('Symbols standard library', () => {
+        it('should allow to access methods & properties defined as part of the standard library', () => {
+            const symbolsTable = new SymbolsTable({
+                id: SymbolString({ name: 'id' }),
+                title: SymbolString({ name: 'title' }),
+            });
+
+            expect(
+                symbolsTable.getSymbolInfo<SymbolType.String>('id')?.definition.properties.length
+            ).toMatchObject({
+                type: 'number',
+                name: 'length',
+                description:
+                    'The length data property of a String value contains the length of the string in UTF-16 code units.',
+            });
+        });
+    });
+
+    describe('getSymbolInfo', () => {
+        it('should add the symbols matching the initial symbol definition passed to the constructor', () => {
+            const symbolsTable = new SymbolsTable(initialSymbols);
+
+            expect(symbolsTable.getSymbolInfo(['visitor'])).toMatchObject({
+                definition: {
+                    type: 'object',
+                    name: 'visitor',
+                    properties: {
+                        claims: {
+                            type: 'object',
+                            name: 'claims',
+                            description: 'The claims contained in the visitor JWT token',
+                            properties: {
+                                key: {
+                                    type: 'string',
+                                    name: 'key',
+                                },
+                                flags: {
+                                    type: 'object',
+                                    name: 'flags',
+                                    properties: {
+                                        FLAG1: {
+                                            type: 'string',
+                                            name: 'FLAG1',
+                                        },
+                                        FLAG2: {
+                                            type: 'string',
+                                            name: 'FLAG2',
+                                        },
+                                        FLAG3: {
+                                            type: 'string',
+                                            name: 'FLAG3',
+                                        },
+                                    },
+                                    methods: [],
+                                },
+                                hello: {
+                                    type: 'array',
+                                    name: 'hello',
+                                    description: 'An array of string',
+                                    items: {
+                                        type: 'string',
+                                    },
+                                },
+                            },
+                            methods: [],
+                        },
+                    },
+                    methods: [],
+                },
+                ref: 'visitor',
+                childrenRefs: ['visitor.claims'],
+            });
+
+            expect(symbolsTable.getSymbolInfo(['visitor', 'claims'])).toMatchObject({
+                definition: {
+                    type: 'object',
+                    name: 'claims',
+                    description: 'The claims contained in the visitor JWT token',
+                    properties: {
+                        key: {
+                            type: 'string',
+                            name: 'key',
+                        },
+                        flags: {
+                            type: 'object',
+                            name: 'flags',
+                            properties: {
+                                FLAG1: {
+                                    type: 'string',
+                                    name: 'FLAG1',
+                                },
+                                FLAG2: {
+                                    type: 'string',
+                                    name: 'FLAG2',
+                                },
+                                FLAG3: {
+                                    type: 'string',
+                                    name: 'FLAG3',
+                                },
+                            },
+                            methods: [],
+                        },
+                        hello: {
+                            type: 'array',
+                            name: 'hello',
+                            description: 'An array of string',
+                            items: {
+                                type: 'string',
+                            },
+                        },
+                    },
+                    methods: [],
+                },
+                ref: 'visitor.claims',
+                parentRef: 'visitor',
+                childrenRefs: [
+                    'visitor.claims.key',
+                    'visitor.claims.flags',
+                    'visitor.claims.hello',
+                ],
+            });
+
+            expect(symbolsTable.getSymbolInfo(['visitor', 'claims', 'key'])).toMatchObject({
+                definition: {
+                    type: 'string',
+                    name: 'key',
+                },
+                ref: 'visitor.claims.key',
+                parentRef: 'visitor.claims',
+                childrenRefs: [
+                    'visitor.claims.key.length',
+                    'visitor.claims.key.at',
+                    'visitor.claims.key.endsWith',
+                    'visitor.claims.key.includes',
+                ],
+            });
+
+            expect(symbolsTable.getSymbolInfo(['visitor', 'claims', 'flags'])).toMatchObject({
+                definition: {
+                    type: 'object',
+                    name: 'flags',
+                    properties: {
+                        FLAG1: {
+                            type: 'string',
+                            name: 'FLAG1',
+                        },
+                        FLAG2: {
+                            type: 'string',
+                            name: 'FLAG2',
+                        },
+                        FLAG3: {
+                            type: 'string',
+                            name: 'FLAG3',
+                        },
+                    },
+                    methods: [],
+                },
+                ref: 'visitor.claims.flags',
+                parentRef: 'visitor.claims',
+                childrenRefs: [
+                    'visitor.claims.flags.FLAG1',
+                    'visitor.claims.flags.FLAG2',
+                    'visitor.claims.flags.FLAG3',
+                ],
+            });
+
+            expect(
+                symbolsTable.getSymbolInfo(['visitor', 'claims', 'flags', 'FLAG1'])
+            ).toMatchObject({
+                definition: {
+                    type: 'string',
+                    name: 'FLAG1',
+                },
+                ref: 'visitor.claims.flags.FLAG1',
+                parentRef: 'visitor.claims.flags',
+                childrenRefs: [
+                    'visitor.claims.flags.FLAG1.length',
+                    'visitor.claims.flags.FLAG1.at',
+                    'visitor.claims.flags.FLAG1.endsWith',
+                    'visitor.claims.flags.FLAG1.includes',
+                ],
+            });
+
+            expect(
+                symbolsTable.getSymbolInfo(['visitor', 'claims', 'flags', 'FLAG2'])
+            ).toMatchObject({
+                definition: {
+                    type: 'string',
+                    name: 'FLAG2',
+                },
+                ref: 'visitor.claims.flags.FLAG2',
+                parentRef: 'visitor.claims.flags',
+                childrenRefs: [
+                    'visitor.claims.flags.FLAG2.length',
+                    'visitor.claims.flags.FLAG2.at',
+                    'visitor.claims.flags.FLAG2.endsWith',
+                    'visitor.claims.flags.FLAG2.includes',
+                ],
+            });
+
+            expect(symbolsTable.getSymbolInfo(['visitor', 'claims', 'hello'])).toMatchObject({
+                definition: {
+                    type: 'array',
+                    name: 'hello',
+                    description: 'An array of string',
+                    items: {
+                        type: 'string',
+                    },
+                },
+                ref: 'visitor.claims.hello',
+                parentRef: 'visitor.claims',
+                childrenRefs: [
+                    'visitor.claims.hello.length',
+                    'visitor.claims.hello.at',
+                    'visitor.claims.hello.includes',
+                    'visitor.claims.hello.some',
+                    'visitor.claims.hello.every',
+                ],
+            });
+        });
+    });
+
+    describe('inferSymbolFromValue', () => {
+        it('should infer properly a symbol based on a value', () => {
+            const symbolDef = SymbolsTable.inferSymbolFromValue(
+                {
+                    visitor: {
+                        claims: {
+                            key: 'test',
+                            flags: {
+                                FLAG1: 'testflag1',
+                                FLAG2: 'testflag2',
+                                FLAG3: 'testflag3',
+                            },
+                            hello: ['test', 'test1', 'test2'],
+                        },
+                    },
+                },
+                'context'
+            );
+            expect(symbolDef).toMatchObject({
+                type: 'object',
+                name: 'context',
+                properties: {
+                    visitor: {
+                        type: 'object',
+                        name: 'visitor',
+                        properties: {
+                            claims: {
+                                type: 'object',
+                                name: 'claims',
+                                properties: {
+                                    key: {
+                                        type: 'string',
+                                        name: 'key',
+                                    },
+                                    flags: {
+                                        type: 'object',
+                                        name: 'flags',
+                                        properties: {
+                                            FLAG1: {
+                                                type: 'string',
+                                                name: 'FLAG1',
+                                            },
+                                            FLAG2: {
+                                                type: 'string',
+                                                name: 'FLAG2',
+                                            },
+                                            FLAG3: {
+                                                type: 'string',
+                                                name: 'FLAG3',
+                                            },
+                                        },
+                                        methods: [],
+                                    },
+                                    hello: {
+                                        type: 'array',
+                                        name: 'hello',
+                                        items: {
+                                            type: 'string',
+                                        },
+                                    },
+                                },
+                                methods: [],
+                            },
+                        },
+                        methods: [],
+                    },
+                },
+                methods: [],
+            });
+        });
+    });
+
+    describe('inferSymbolFromJSONSchema', () => {
+        it('should infer properly a symbol table based on a JSON schema', () => {
+            const symbolDef = SymbolsTable.inferSymbolFromJSONSchema(
+                {
+                    type: 'object',
+                    description: `The attributes tied to a site's visitor.`,
+                    properties: {
+                        claims: {
+                            type: 'object',
+                            properties: {
+                                key: {
+                                    type: 'string',
+                                },
+                                flags: {
+                                    type: 'object',
+                                    description: 'The user feature flags',
+                                    properties: {
+                                        FLAG1: { type: 'string' },
+                                        FLAG2: { type: 'string' },
+                                        FLAG3: { type: 'string' },
+                                    },
+                                },
+                                hello: {
+                                    type: 'string',
+                                    enum: ['test', 'test1', 'test2'],
+                                },
+                            },
+                        },
+                    },
+                },
+                'visitor'
+            );
+            expect(symbolDef).toMatchObject({
+                type: 'object',
+                name: 'visitor',
+                description: `The attributes tied to a site's visitor.`,
+                properties: {
+                    claims: {
+                        type: 'object',
+                        name: 'claims',
+                        properties: {
+                            key: {
+                                type: 'string',
+                                name: 'key',
+                            },
+                            flags: {
+                                type: 'object',
+                                name: 'flags',
+                                description: 'The user feature flags',
+                                properties: {
+                                    FLAG1: {
+                                        type: 'string',
+                                        name: 'FLAG1',
+                                    },
+                                    FLAG2: {
+                                        type: 'string',
+                                        name: 'FLAG2',
+                                    },
+                                    FLAG3: {
+                                        type: 'string',
+                                        name: 'FLAG3',
+                                    },
+                                },
+                                methods: [],
+                            },
+                            hello: {
+                                type: 'string',
+                                enum: ['test', 'test1', 'test2'],
+                            },
+                        },
+                        methods: [],
+                    },
+                },
+                methods: [],
+            });
+        });
+    });
+});

packages/expr/src/symbols/index.ts

@@ -0,0 +1,3 @@
+export * from './symbols';
+export * from './symbols-table';
+export * from './types';

packages/expr/src/symbols/symbols-table.ts

@@ -0,0 +1,350 @@
+import type { JSONSchema7 } from 'json-schema';
+
+import { filterOutNullable } from '../utils';
+import {
+    SymbolArray,
+    SymbolBoolean,
+    SymbolNull,
+    SymbolNumber,
+    SymbolObject,
+    SymbolString,
+    SymbolUndefined,
+} from './symbols';
+import {
+    type ExtractSymbolDef,
+    type GenericSymbolDef,
+    type ObjectSymbolDef,
+    SymbolType,
+    type SymbolWithMethods,
+    type SymbolWithProperties,
+    resolveSymbolDef,
+} from './types';
+
+export interface SymbolInfo<T extends SymbolType = SymbolType> {
+    /**
+     * Definition of the symbol.
+     */
+    definition: ExtractSymbolDef<T>;
+
+    /**
+     * Reference of the symbol in the table of symbols.
+     */
+    ref: string;
+
+    /**
+     * Stores the reference to the parent symbol.
+     */
+    parentRef?: string;
+
+    /**
+     * Stores the reference to the children symbols.
+     */
+    childrenRefs?: string[];
+}
+
+export class SymbolError extends Error {
+    constructor(message: string) {
+        super(message);
+
+        if (Error.captureStackTrace) {
+            Error.captureStackTrace(this, SymbolError);
+        }
+        this.name = 'SymbolError';
+    }
+}
+
+export class SymbolsTable {
+    /**
+     * Internal table that keeps track of all symbols reference.
+     */
+    #table: Record<string, SymbolInfo>;
+
+    /**
+     * Internal table that keep track of the raw symbols definitions.
+     */
+    #rawSymbols: Record<string, GenericSymbolDef>;
+
+    constructor(initialContext: Record<string, GenericSymbolDef> = {}) {
+        this.#table = {};
+        this.#rawSymbols = {};
+        this.addSymbols(initialContext);
+    }
+
+    /**
+     * Create a new symbols table by merging the current one with the provided one.
+     */
+    merge(other: SymbolsTable): SymbolsTable {
+        return new SymbolsTable({
+            ...this.#rawSymbols,
+            ...other.#rawSymbols,
+        });
+    }
+
+    toString() {
+        return JSON.stringify(this.#table, null, 2);
+    }
+
+    /**
+     * Infer the symbol of a value and generate the appropriate symbol definition.
+     */
+    static inferSymbolFromValue(value: unknown, name?: string): ExtractSymbolDef<SymbolType> {
+        if (Array.isArray(value)) {
+            if (value.length === 0) {
+                return SymbolArray({ items: SymbolUndefined() });
+            }
+
+            const firstItemSymbol = SymbolsTable.inferSymbolFromValue(value.at(0));
+            // Check that the array is not a mixin of different items types.
+            if (value.length > 1) {
+                const secondItemSymbol = SymbolsTable.inferSymbolFromValue(value.at(1));
+                if (firstItemSymbol.type !== secondItemSymbol.type) {
+                    throw new SymbolError('Array with mixin items types are not supported');
+                }
+            }
+            return SymbolArray({ name, items: firstItemSymbol });
+        }
+
+        if (typeof value === 'undefined') {
+            return SymbolUndefined({ name });
+        }
+
+        if (value === null) {
+            return SymbolNull({ name });
+        }
+
+        const valueType = typeof value;
+        switch (valueType) {
+            case 'string':
+                return SymbolString({ name });
+            case 'number':
+                return SymbolNumber({ name });
+            case 'boolean':
+                return SymbolBoolean({ name });
+            case 'object': {
+                const properties = Object.entries(value).reduce<Record<string, GenericSymbolDef>>(
+                    (prev, [name, val]) => {
+                        prev[name] = SymbolsTable.inferSymbolFromValue(val, name);
+                        return prev;
+                    },
+                    {}
+                );
+                return SymbolObject({ name, properties, methods: [] });
+            }
+            default:
+                throw new SymbolError(`Unsupported symbol type ${valueType}`);
+        }
+    }
+
+    /**
+     * Infer a table of symbol based on a JSON schema object describing it.
+     */
+    static inferSymbolFromJSONSchema(
+        schema: JSONSchema7,
+        name?: string
+    ): ExtractSymbolDef<SymbolType> {
+        switch (schema.type) {
+            case 'string':
+                return SymbolString({
+                    name,
+                    ...(schema.description ? { description: schema.description } : {}),
+                    ...(schema.enum
+                        ? {
+                              enum: schema.enum
+                                  .filter(filterOutNullable)
+                                  .map((enumValue) => enumValue.toString()),
+                          }
+                        : {}),
+                });
+            case 'number':
+            case 'integer':
+                return SymbolNumber({
+                    name,
+                    ...(schema.description ? { description: schema.description } : {}),
+                });
+            case 'boolean':
+                return SymbolBoolean({
+                    name,
+                    ...(schema.description ? { description: schema.description } : {}),
+                });
+            case 'null':
+                return SymbolNull({
+                    name,
+                    ...(schema.description ? { description: schema.description } : {}),
+                });
+            case 'object':
+                return SymbolsTable.#buildObjectSymbolFromJSONSchemaObject(schema, name);
+            case 'array':
+                return SymbolsTable.#buildArraySymbolFromJSONSchemaArray(schema, name);
+            default:
+                throw new Error(`Unsupported schema type: ${schema.type}`);
+        }
+    }
+
+    static #buildObjectSymbolFromJSONSchemaObject(
+        schema: JSONSchema7,
+        name?: string
+    ): ObjectSymbolDef {
+        const properties: Record<string, GenericSymbolDef> = {};
+
+        if (schema.properties) {
+            Object.entries(schema.properties).forEach(([propertyName, propertySchema]) => {
+                properties[propertyName] = SymbolsTable.inferSymbolFromJSONSchema(
+                    propertySchema as JSONSchema7,
+                    propertyName
+                );
+            });
+        }
+
+        return SymbolObject({
+            name,
+            properties,
+            ...(schema.description ? { description: schema.description } : {}),
+            methods: [],
+        });
+    }
+
+    static #buildArraySymbolFromJSONSchemaArray(
+        schema: JSONSchema7,
+        name?: string
+    ): ExtractSymbolDef<SymbolType.Array> {
+        if (schema.items) {
+            const itemSymbol = SymbolsTable.inferSymbolFromJSONSchema(
+                schema.items as JSONSchema7,
+                `${name || ''}_item`
+            );
+            return SymbolArray({
+                name,
+                ...(schema.description ? { description: schema.description } : {}),
+                items: itemSymbol,
+            });
+        }
+
+        return SymbolArray({
+            name,
+            ...(schema.description ? { description: schema.description } : {}),
+            items: SymbolUndefined(),
+        });
+    }
+
+    private generateSymbolRefPath(path: string[]): string {
+        return path.join('.');
+    }
+
+    /**
+     * Add a single symbol to the table at the provided path.
+     */
+    private addSymbol(path: string[], definition: GenericSymbolDef, raw = false): void {
+        const fullPath = this.generateSymbolRefPath(path);
+        const parentPath = path.slice(0, -1).join('.');
+
+        if (this.#table[fullPath]) {
+            throw new SymbolError(`Symbol "${fullPath}" already exists.`);
+        }
+
+        if (raw) {
+            this.#rawSymbols[fullPath] = definition;
+        }
+
+        // Add the new symbol linking it to its parent
+        this.#table[fullPath] = {
+            definition: resolveSymbolDef(definition),
+            ref: fullPath,
+            parentRef: parentPath || undefined,
+            childrenRefs: [],
+        };
+
+        if (parentPath && this.#table[parentPath]) {
+            if (this.#table[parentPath].childrenRefs) {
+                this.#table[parentPath].childrenRefs.push(fullPath);
+            }
+        }
+
+        // Add any nested symbols if the value is a symbol with properties...
+        if (isSymbolWithProperties(definition)) {
+            Object.entries(definition.properties).forEach(([propKey, propSymbol]) => {
+                if (isObjectSymbol(propSymbol)) {
+                    this.addSymbols({ [propKey]: propSymbol }, path, false);
+                } else {
+                    this.addSymbol([...path, propKey], propSymbol, false);
+                }
+            });
+        }
+
+        // ...or a symbol with methods
+        if (isSymbolWithMethods(definition)) {
+            definition.methods.forEach((methodSymbol) => {
+                this.addSymbol([...path, methodSymbol.name], methodSymbol, false);
+            });
+        }
+    }
+
+    /**
+     * Add the provided object of symbols definitions to the symbol table.
+     */
+    public addSymbols(
+        symbols: Record<string, GenericSymbolDef>,
+        prefix: string[] = [],
+        raw = true
+    ): void {
+        for (const [key, symbolDef] of Object.entries(symbols)) {
+            const path = [...prefix, key];
+
+            // Add the current symbol to the table.
+            this.addSymbol(path, symbolDef, raw);
+        }
+    }
+
+    /**
+     * Get a symbol's information using its path in the table.
+     */
+    public getSymbolInfo<T extends SymbolType>(path: string | string[]): SymbolInfo<T> | undefined {
+        const key = Array.isArray(path) ? path.join('.') : path;
+        const info = this.#table[key];
+        return info ? typedSymbolInfo(info) : undefined;
+    }
+
+    /**
+     * Get all symbol keys matching the pattern defined by the provided path.
+     */
+    public getMatchingSymbolsKeys(path: string[]): string[] {
+        const wildcardRegex = new RegExp(
+            `^${path
+                .map((segment) => {
+                    if (segment.includes('*')) {
+                        return `${segment.split('*')[0]}([^.]+)?`;
+                    }
+                    return segment;
+                })
+                .join('\\.')}$`
+        );
+
+        return Object.keys(this.#table)
+            .filter((key) => wildcardRegex.test(key))
+            .filter(filterOutNullable);
+    }
+}
+
+function isObjectSymbol(symbol: GenericSymbolDef): symbol is ObjectSymbolDef {
+    return symbol.type === SymbolType.Object;
+}
+
+function isSymbolWithProperties(symbol: GenericSymbolDef): symbol is SymbolWithProperties {
+    return (
+        symbol.type === SymbolType.Object ||
+        symbol.type === SymbolType.Array ||
+        symbol.type === SymbolType.String
+    );
+}
+
+function isSymbolWithMethods(symbol: GenericSymbolDef): symbol is SymbolWithMethods {
+    return (
+        symbol.type === SymbolType.Object ||
+        symbol.type === SymbolType.Array ||
+        symbol.type === SymbolType.String
+    );
+}
+
+function typedSymbolInfo<T extends SymbolType>(info: SymbolInfo): SymbolInfo<T> {
+    const definition = resolveSymbolDef(info.definition);
+    return { ...info, definition } as SymbolInfo<T>;
+}

packages/expr/src/symbols/symbols.ts

@@ -0,0 +1,322 @@
+import {
+    type ArraySymbolDef,
+    type BooleanSymbolDef,
+    type ExtractSymbolDef,
+    type FunctionSymbolDef,
+    type GenericSymbolDef,
+    type NullSymbolDef,
+    type NumberSymbolDef,
+    type ObjectSymbolDef,
+    type StringSymbolDef,
+    SymbolType,
+    type SymbolsWithPropertiesAndMethods,
+    type UndefinedSymbolDef,
+    type UnionSymbolDef,
+} from './types';
+
+export function SymbolBoolean(args: Omit<BooleanSymbolDef, 'type'> = {}): BooleanSymbolDef {
+    return {
+        type: SymbolType.Boolean,
+        ...args,
+    };
+}
+
+export function SymbolNumber(args: Omit<NumberSymbolDef, 'type'> = {}): NumberSymbolDef {
+    return {
+        type: SymbolType.Number,
+        ...args,
+    };
+}
+
+export function SymbolString(
+    args: Omit<StringSymbolDef, 'type' | 'methods' | 'properties'> = {}
+): StringSymbolDef {
+    return createSymbolWithPropertiesAndMethods<StringSymbolDef>(SymbolType.String, args);
+}
+
+export function SymbolObject(args: Omit<ObjectSymbolDef, 'type'>): ObjectSymbolDef {
+    return {
+        type: SymbolType.Object,
+        ...args,
+    };
+}
+
+export function SymbolArray(
+    args: Omit<ArraySymbolDef, 'type' | 'methods' | 'properties'>
+): ArraySymbolDef {
+    return createSymbolWithPropertiesAndMethods(SymbolType.Array, args);
+}
+
+export function SymbolFunction(args: Omit<FunctionSymbolDef, 'type'>): FunctionSymbolDef {
+    return {
+        type: SymbolType.Function,
+        ...args,
+    };
+}
+
+export function OptionalFunctionArg(
+    optionalArg: ExtractSymbolDef<SymbolType>
+): ExtractSymbolDef<SymbolType> & { optional: true } {
+    return {
+        ...optionalArg,
+        optional: true,
+    };
+}
+
+export function SymbolUnion(args: Omit<UnionSymbolDef, 'type'>): UnionSymbolDef {
+    return {
+        type: SymbolType.Union,
+        ...args,
+    };
+}
+
+export function SymbolUndefined(args: Omit<UndefinedSymbolDef, 'type'> = {}): UndefinedSymbolDef {
+    return {
+        type: SymbolType.Undefined,
+        ...args,
+    };
+}
+
+export function SymbolNull(args: Omit<NullSymbolDef, 'type'> = {}): NullSymbolDef {
+    return {
+        type: SymbolType.Null,
+        ...args,
+    };
+}
+
+function createSymbolWithPropertiesAndMethods<
+    T extends SymbolsWithPropertiesAndMethods & { type: SymbolType },
+>(type: T['type'], args: Omit<T, 'type' | 'methods' | 'properties'>): T {
+    const symbol = { type, ...args } as T;
+
+    Object.defineProperty(symbol, 'properties', {
+        get() {
+            if (symbol.type === SymbolType.Array) {
+                return isArraySymbol(symbol)
+                    ? StandardLibrary[SymbolType.Array]?.(symbol).properties
+                    : {};
+            }
+            return StandardLibrary[symbol.type]?.properties || {};
+        },
+    });
+
+    Object.defineProperty(symbol, 'methods', {
+        get() {
+            if (symbol.type === SymbolType.Array) {
+                return isArraySymbol(symbol)
+                    ? StandardLibrary[SymbolType.Array]?.(symbol).methods
+                    : [];
+            }
+            return StandardLibrary[symbol.type]?.methods || [];
+        },
+    });
+
+    return symbol;
+}
+
+// TODO-ADAPTIVE-CONTENT: extend the definition of the supported standard library methods and properties.
+
+const StandardLibrary: Partial<
+    {
+        [key in Exclude<SymbolType, SymbolType.Array>]: {
+            properties: Record<string, GenericSymbolDef>;
+            methods: FunctionSymbolDef[];
+        };
+    } & {
+        [SymbolType.Array]: (symbol: ArraySymbolDef) => {
+            properties: Record<string, GenericSymbolDef>;
+            methods: FunctionSymbolDef[];
+        };
+    }
+> = {
+    [SymbolType.String]: {
+        properties: {
+            length: SymbolNumber({
+                name: 'length',
+                description:
+                    'The length data property of a String value contains the length of the string in UTF-16 code units.',
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length',
+            }),
+        },
+        methods: [
+            SymbolFunction({
+                name: 'at',
+                description: `Takes an integer value and returns the item at that index, allowing for positive and negative integers.
+            Negative integers count back from the last item in the string.`,
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/at',
+                args: [
+                    SymbolNumber({
+                        name: 'index',
+                        description: 'The index (position) of the string character to be returned',
+                    }),
+                ],
+                returns: SymbolUnion({
+                    description: `A String consisting of the single UTF-16 code unit located at the specified position.
+                Returns undefined if the given index can not be found.`,
+                    members: [SymbolString(), SymbolUndefined()],
+                }),
+            }),
+            SymbolFunction({
+                name: 'endsWith',
+                description: `Returns true if the sequence of elements of searchString converted to a String is the same as the corresponding 
+            elements of this object (converted to a String) starting at endPosition – length(this). Otherwise returns false.`,
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/endsWith',
+                args: [
+                    SymbolString({
+                        name: 'searchString',
+                        description: `The characters to be searched for at the end of str. Cannot be a regex.
+                    All values that are not regexes are coerced to strings, so omitting it or passing undefined causes endsWith() to search for 
+                    the string "undefined", which is rarely what you want.`,
+                    }),
+                    OptionalFunctionArg(
+                        SymbolNumber({
+                            name: 'endPosition',
+                            description: `The end position at which searchString is expected to be found 
+                    (the index of searchString's last character plus 1). Defaults to str.length.`,
+                        })
+                    ),
+                ],
+                returns: SymbolBoolean({
+                    description: `true if the given characters are found at the end of the string, including when searchString is an empty string; 
+                otherwise, false.`,
+                }),
+            }),
+            SymbolFunction({
+                name: 'includes',
+                description: `Returns true if searchString appears as a substring of the result of converting this object to a String, at one or more positions 
+            that are greater than or equal to position; otherwise, returns false.`,
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes',
+                args: [
+                    SymbolString({
+                        name: 'searchString',
+                        description: `A string to be searched for within str. Cannot be a regex. All values that are not regexes are coerced to strings, so omitting it 
+                or passing undefined causes includes() to search for the string "undefined", which is rarely what you want.`,
+                    }),
+                    OptionalFunctionArg(
+                        SymbolNumber({
+                            name: 'position',
+                            description:
+                                'The position within the string at which to begin searching for searchString. (Defaults to 0.)',
+                        })
+                    ),
+                ],
+                returns: SymbolBoolean({
+                    description: `true if the search string is found anywhere within the given string, including when searchString is an empty string; 
+                otherwise, false.`,
+                }),
+            }),
+        ],
+    },
+    [SymbolType.Array]: (arraySymbolDef: ArraySymbolDef) => ({
+        properties: {
+            length: SymbolNumber({
+                name: 'length',
+                description: `The length data property of an Array instance represents the number of elements in that array.
+                The value is an unsigned, 32-bit integer that is always numerically greater than the highest index in the array.`,
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/length',
+            }),
+        },
+        methods: [
+            SymbolFunction({
+                name: 'at',
+                description: `Takes an integer value and returns the item at that index, allowing for positive and negative integers. 
+                Negative integers count back from the last item in the array.`,
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/at',
+                args: [
+                    SymbolNumber({
+                        name: 'index',
+                        description: `Zero-based index of the array element to be returned, converted to an integer. 
+                        Negative index counts back from the end of the array — if index < 0, index + array.length is accessed.`,
+                    }),
+                ],
+                returns: SymbolUnion({
+                    description: `The element in the array matching the given index. Always returns undefined if index < -array.length or index >= array.length 
+                    without attempting to access the corresponding property.`,
+                    members: [arraySymbolDef.items, SymbolUndefined()],
+                }),
+            }),
+            SymbolFunction({
+                name: 'includes',
+                description:
+                    'Determines whether an array includes a certain value among its entries, returning true or false as appropriate.',
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes',
+                args: [
+                    {
+                        ...arraySymbolDef.items,
+                        name: 'searchElement',
+                        description: 'The value to be searched for within the array.',
+                    },
+                    OptionalFunctionArg(
+                        SymbolNumber({
+                            name: 'fromIndex',
+                            description:
+                                'The position within the string at which to begin searching for searchString. (Defaults to 0.)',
+                        })
+                    ),
+                ],
+                returns: SymbolBoolean({
+                    description:
+                        'true if the value searchElement is found within the array (or the part of the array indicated by the index fromIndex, if specified).',
+                }),
+            }),
+            SymbolFunction({
+                name: 'some',
+                description:
+                    'Tests whether at least one element in the array passes the test implemented by the provided function.',
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/some',
+                args: [
+                    SymbolFunction({
+                        name: 'callback',
+                        description: 'A function that tests each element of the array.',
+                        args: [
+                            {
+                                ...arraySymbolDef.items,
+                                name: 'element',
+                                description: 'The current element being processed in the array.',
+                            },
+                        ],
+                        returns: SymbolBoolean({
+                            description:
+                                'true if the callback function returns a truthy value for at least one element in the array.',
+                        }),
+                    }),
+                ],
+                returns: SymbolBoolean({
+                    description:
+                        'true if the callback function returns a truthy value for at least one element in the array.',
+                }),
+            }),
+            SymbolFunction({
+                name: 'every',
+                description:
+                    'Tests whether all elements in the array pass the test implemented by the provided function.',
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every',
+                args: [
+                    SymbolFunction({
+                        name: 'callback',
+                        description: 'A function that tests each element of the array.',
+                        args: [
+                            {
+                                ...arraySymbolDef.items,
+                                name: 'element',
+                                description: 'The current element being processed in the array.',
+                            },
+                        ],
+                        returns: SymbolBoolean({
+                            description:
+                                'true if the callback function returns a truthy value for all elements in the array.',
+                        }),
+                    }),
+                ],
+                returns: SymbolBoolean({
+                    description:
+                        'true if the callback function returns a truthy value for all elements in the array.',
+                }),
+            }),
+        ],
+    }),
+};
+
+function isArraySymbol(symbol: GenericSymbolDef): symbol is ArraySymbolDef {
+    return symbol.type === SymbolType.Array;
+}

packages/expr/src/symbols/types.ts

@@ -0,0 +1,193 @@
+import type { MandateProps } from '../utils';
+
+export enum SymbolType {
+    Boolean = 'boolean',
+    Number = 'number',
+    String = 'string',
+    Object = 'object',
+    Array = 'array',
+    Function = 'function',
+    Union = 'union',
+    Undefined = 'undefined',
+    Null = 'null',
+}
+
+export interface SymbolMetadata {
+    /**
+     * Long description of the symbol.
+     */
+    description?: string;
+
+    /**
+     * Link to a documentation/manual page.
+     */
+    link?: string;
+}
+
+export interface GenericSymbolDef extends SymbolMetadata {
+    /**
+     * Type of the symbol.
+     */
+    type: SymbolType;
+
+    /**
+     * Name of the symbol.
+     */
+    name?: string;
+}
+
+export interface SymbolWithProperties extends GenericSymbolDef {
+    /**
+     * Properties on the symbol type.
+     */
+    properties: Record<string, GenericSymbolDef>;
+}
+
+export interface SymbolWithMethods extends GenericSymbolDef {
+    /**
+     * Methods that can be called on the symbol type.
+     */
+    methods: FunctionSymbolDef[];
+}
+
+export interface BooleanSymbolDef extends GenericSymbolDef {
+    type: SymbolType.Boolean;
+}
+
+export interface NumberSymbolDef extends GenericSymbolDef {
+    type: SymbolType.Number;
+}
+
+export interface StringSymbolDef extends SymbolWithProperties, SymbolWithMethods {
+    type: SymbolType.String;
+
+    /**
+     * Set of enumerated values that the string symbol is retristred to.
+     */
+    enum?: string[];
+
+    /**
+     * Properties on strings.
+     */
+    properties: {
+        length: NumberSymbolDef;
+    };
+}
+
+export interface ObjectSymbolDef extends SymbolWithProperties, SymbolWithMethods {
+    type: SymbolType.Object;
+}
+
+export interface ArraySymbolDef extends SymbolWithProperties, SymbolWithMethods {
+    type: SymbolType.Array;
+
+    /**
+     * Symbol representing the type of the items of the array
+     */
+    items: ExtractSymbolDef<SymbolType>;
+
+    /**
+     * Properties on arrays.
+     */
+    properties: {
+        length: NumberSymbolDef;
+    };
+}
+
+export interface FunctionSymbolDef extends MandateProps<GenericSymbolDef, 'name'> {
+    type: SymbolType.Function;
+
+    /**
+     * Symbols describing the arguments of the function.
+     */
+    args: (ExtractSymbolDef<SymbolType> & { optional?: boolean })[];
+
+    /**
+     * Symbol describing the returned value of the function.
+     */
+    returns: ExtractSymbolDef<SymbolType>;
+}
+
+export interface UnionSymbolDef extends GenericSymbolDef {
+    type: SymbolType.Union;
+
+    /**
+     * Symbols composing the union.
+     */
+    members: ExtractSymbolDef<SymbolType>[];
+}
+
+export interface UndefinedSymbolDef extends GenericSymbolDef {
+    type: SymbolType.Undefined;
+}
+
+export interface NullSymbolDef extends GenericSymbolDef {
+    type: SymbolType.Null;
+}
+
+export type SymbolsWithPropertiesAndMethods = ArraySymbolDef | ObjectSymbolDef | StringSymbolDef;
+
+export type ExtractSymbolDef<T extends SymbolType> = T extends SymbolType.String
+    ? StringSymbolDef
+    : T extends SymbolType.Number
+      ? NumberSymbolDef
+      : T extends SymbolType.Boolean
+        ? BooleanSymbolDef
+        : T extends SymbolType.Array
+          ? ArraySymbolDef
+          : T extends SymbolType.Object
+            ? ObjectSymbolDef
+            : T extends SymbolType.Function
+              ? FunctionSymbolDef
+              : T extends SymbolType.Union
+                ? UnionSymbolDef
+                : T extends SymbolType.Undefined
+                  ? UndefinedSymbolDef
+                  : T extends SymbolType.Null
+                    ? NullSymbolDef
+                    : never;
+
+export function resolveSymbolDef(
+    symbol: GenericSymbolDef
+):
+    | StringSymbolDef
+    | NumberSymbolDef
+    | BooleanSymbolDef
+    | ArraySymbolDef
+    | ObjectSymbolDef
+    | FunctionSymbolDef
+    | UnionSymbolDef
+    | UndefinedSymbolDef
+    | NullSymbolDef {
+    switch (symbol.type) {
+        case SymbolType.String:
+            return symbol as StringSymbolDef;
+
+        case SymbolType.Number:
+            return symbol as NumberSymbolDef;
+
+        case SymbolType.Boolean:
+            return symbol as BooleanSymbolDef;
+
+        case SymbolType.Array:
+            return symbol as ArraySymbolDef;
+
+        case SymbolType.Object:
+            return symbol as ObjectSymbolDef;
+
+        case SymbolType.Function:
+            return symbol as FunctionSymbolDef;
+
+        case SymbolType.Union:
+            return symbol as UnionSymbolDef;
+
+        case SymbolType.Undefined:
+            return symbol as UndefinedSymbolDef;
+
+        case SymbolType.Null:
+            return symbol as NullSymbolDef;
+
+        default:
+            throw new Error(`Unknown symbol type: ${symbol.type}`);
+    }
+}

packages/expr/src/template.ts

@@ -0,0 +1,57 @@
+export type TemplateText = {
+    type: 'text';
+    value: string;
+    start: number;
+    end: number;
+};
+
+export type TemplateExpression = {
+    type: 'expression';
+    value: string;
+    start: number; // Start index of the expression content (after `{{`)
+    end: number; // End index of the expression content (before `}}`)
+};
+
+export type TemplatePart = TemplateText | TemplateExpression;
+
+/**
+ * Parse a template string containing `{{ expression }}` placeholders.
+ */
+export function parseTemplate(template: string): TemplatePart[] {
+    const parts: TemplatePart[] = [];
+    const regex = /\{\{(.*?)\}\}/gs;
+    let lastIndex = 0;
+
+    for (const match of template.matchAll(regex)) {
+        const matchStart = match.index ?? 0;
+        const matchEnd = matchStart + match[0].length;
+
+        if (matchStart > lastIndex) {
+            parts.push({
+                type: 'text',
+                value: template.slice(lastIndex, matchStart),
+                start: lastIndex,
+                end: matchStart,
+            });
+        }
+
+        parts.push({
+            type: 'expression',
+            value: (match[1] ?? '').trim(),
+            start: matchStart + 2,
+            end: matchEnd - 2,
+        });
+        lastIndex = matchEnd;
+    }
+
+    if (lastIndex < template.length) {
+        parts.push({
+            type: 'text',
+            value: template.slice(lastIndex),
+            start: lastIndex,
+            end: template.length,
+        });
+    }
+
+    return parts;
+}

packages/expr/src/types.ts

@@ -0,0 +1,176 @@
+import type { BinaryOperator, Expression, ExpressionStatement, LogicalOperator } from 'acorn';
+
+import type { ArraySymbolDef, SymbolInfo, SymbolType } from './symbols';
+
+export interface ExpressionGenerator {
+    /**
+     * Converts an ESTree compatible AST node into a string representing the corresponding expression.
+     */
+    generate(node: Expression): string;
+}
+
+export interface ExpressionParserResult {
+    /**
+     * The expression statement from the valid portion of the parsed expression.
+     *
+     * It is undefined when no valid expression statements could be found.
+     */
+    result: Expression;
+
+    /**
+     * The information of the invalid (non-expression) nodes found from the other portions of the parsed expression.
+     */
+    invalidNodes: Array<ExpressionStatement>;
+}
+
+export interface ExpressionAutocompleteResults {
+    suggestions: AutocompleteSuggestions;
+}
+
+type ConditionalOperator = '?';
+
+export const SUPPORTED_BINARY_OPERATORS = [
+    {
+        operator: '==',
+        description: 'Checks whether two values are equal.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Equality',
+    },
+    {
+        operator: '!=',
+        description: 'Checks whether two values are unequal.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Inequality',
+    },
+    {
+        operator: '===',
+        description: 'Checks whether two values are equal (strict comparison).',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Strict_equality',
+    },
+    {
+        operator: '!==',
+        description: 'Checks whether two values are unequal (strict comparison).',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Strict_inequality',
+    },
+    {
+        operator: '<',
+        description: 'Checks if the left value is less than the right value.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Less_than',
+    },
+    {
+        operator: '<=',
+        description: 'Checks if the left value is less than or equal to the right value.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Less_than_or_equal',
+    },
+    {
+        operator: '>',
+        description: 'Checks if the left value is greater than the right value.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Greater_than',
+    },
+    {
+        operator: '>=',
+        description: 'Checks if the left value is greater than or equal to the right value.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Greater_than_or_equal',
+    },
+    {
+        operator: 'in',
+        description: 'Checks if a property exists in an object or if a value is in an array.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/in',
+    },
+] as const;
+
+export const SUPPORTED_LOGICAL_OPERATORS = [
+    {
+        operator: '&&',
+        description: 'Logical AND operator; returns true if both operands are true.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_AND',
+    },
+    {
+        operator: '||',
+        description: 'Logical OR operator; returns true if at least one operand is true.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_OR',
+    },
+] as const;
+
+export const SUPPORTED_CONDITIONAL_OPERATORS = [
+    {
+        operator: '?',
+        description:
+            'Conditional (ternary) operator; returns one of two values based on a condition.',
+        link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator',
+    },
+] as const;
+
+type DirectLiteralValue = {
+    kind: 'direct';
+} & (
+    | {
+          type: SymbolType.Boolean;
+          data: boolean;
+      }
+    | {
+          type: SymbolType.Number;
+          data: number;
+      }
+    | {
+          type: SymbolType.String;
+          data: string;
+      }
+    | {
+          type: SymbolType.Null;
+          data: null;
+      }
+);
+
+type InArrayLiteralValue = {
+    kind: 'in-array';
+    srcSymbol: ArraySymbolDef;
+    matchedLiteralString: string;
+};
+
+export type DirectLiteralValueSuggestion = {
+    type: 'literal-value';
+    value: DirectLiteralValue;
+};
+
+export type InArrayLiteralValueSuggestion = {
+    type: 'literal-value';
+    value: InArrayLiteralValue;
+};
+
+export type AutocompleteLiteralValueSuggestion =
+    | DirectLiteralValueSuggestion
+    | InArrayLiteralValueSuggestion;
+
+export interface AutocompleteOperatorSuggestion {
+    type: 'operator';
+    operator:
+        | Extract<BinaryOperator, (typeof SUPPORTED_BINARY_OPERATORS)[number]['operator']>
+        | Extract<LogicalOperator, (typeof SUPPORTED_LOGICAL_OPERATORS)[number]['operator']>
+        | Extract<
+              ConditionalOperator,
+              (typeof SUPPORTED_CONDITIONAL_OPERATORS)[number]['operator']
+          >;
+    description: string;
+    link: string;
+}
+
+export interface AutocompleteSymbolSuggestion {
+    type: 'symbol';
+    symbol: SymbolInfo;
+}
+
+export type AutocompleteSuggestions = Array<
+    | AutocompleteSymbolSuggestion
+    | AutocompleteLiteralValueSuggestion
+    | AutocompleteOperatorSuggestion
+>;
+
+type LoggerFn = (message: string, ...args: any[]) => void;
+
+/**
+ * A logger that can be passed to the runtime.
+ */
+export interface Logger {
+    debug: LoggerFn;
+    info: LoggerFn;
+    error: LoggerFn;
+}

packages/expr/src/utils.ts

@@ -0,0 +1,40 @@
+/**
+ * Format the result value of an expression for display as a string.
+ */
+export function formatExpressionResult(value: any, defaultValue = ''): string {
+    if (value === undefined || value === null) {
+        return defaultValue;
+    }
+
+    if (typeof value === 'string') {
+        return value;
+    }
+
+    if (typeof value === 'number' || typeof value === 'boolean') {
+        return value.toString();
+    }
+
+    return defaultValue;
+}
+
+/**
+ * Filter function to exclude `null` values
+ */
+export function filterOutNullable<T>(value: T): value is NonNullable<T> {
+    return !!value;
+}
+
+/**
+ * Type to make optional properties on a object mandatory.
+ *
+ * interface SomeObject {
+ *   uid: string;
+ *   price: number | null;
+ *   location?: string;
+ * }
+ *
+ * type ValuableObject = MandateProps<SomeObject, 'price' | 'location'>;
+ */
+export type MandateProps<T extends {}, K extends keyof T> = T & {
+    [MK in K]-?: NonNullable<T[MK]>;
+};

packages/expr/tsconfig.json

@@ -0,0 +1,18 @@
+{
+    "$schema": "https://json.schemastore.org/tsconfig",
+    "extends": ["@tsconfig/strictest/tsconfig.json", "@tsconfig/node20/tsconfig.json"],
+    "compilerOptions": {
+        "lib": ["ESNext", "DOM"],
+        "module": "ESNext",
+        "moduleResolution": "bundler",
+        "isolatedModules": true,
+        "incremental": true,
+        "noEmit": true,
+        "noPropertyAccessFromIndexSignature": false,
+        "exactOptionalPropertyTypes": false,
+        "types": [
+            "bun-types" // add Bun global
+        ]
+    },
+    "include": ["types/**/*.d.ts", "src/**/*.ts"]
+}

packages/expr/tsdown.config.ts

@@ -0,0 +1,9 @@
+import { defineConfig } from 'tsdown';
+
+export default defineConfig([
+    {
+        entry: ['src/index.ts'],
+        dts: true,
+        format: ['esm'],
+    },
+]);

packages/expr/types/eval-estree-expression.d.ts

@@ -0,0 +1,57 @@
+declare module 'eval-estree-expression' {
+    /**
+     * Options for evaluation and compilation.
+     */
+    export interface EvalESTreeExpressionOptions {
+        /**
+         * Force logical operators to return a boolean result. Default: undefined
+         */
+        booleanLogicalOperators?: boolean;
+        /**
+         * Allow function calls to be evaluated. This is unsafe, please enable this option at your own risk. Default: false
+         */
+        functions?: boolean;
+        /**
+         * Enable support for function statements and expressions by enabling the functions option AND by passing the .generate() function from the escodegen library. Default: undefined
+         */
+        generate?: boolean | ((node: any) => string);
+        /**
+         * Enable the =~ regex operator to support testing values without using functions (example name =~ /^a.*c$/). Default: true
+         */
+        regexOperator?: boolean;
+        /**
+         * Throw an error when variables are undefined. Default: false
+         */
+        strict?: boolean;
+        /**
+         * Used with the variables method to return nested variables (e.g., variables with dot notation, like foo.bar.baz). Default: undefined
+         */
+        withMembers?: boolean;
+    }
+
+    /**
+     * Evaluates an ESTree expression asynchronously against a given context.
+     * @param expression - An object representing an ESTree-compliant AST node.
+     * @param context - An object containing variables and values to be used during evaluation.
+     * @returns A promise resolving to the result of the evaluation.
+     */
+    export function evaluate<ASTNode>(
+        ast: ASTNode,
+        context: object,
+        options?: EvalESTreeExpressionOptions
+    ): Promise<any>;
+
+    /**
+     * Evaluates an ESTree expression synchronously against a given context.
+     * @param expression - An object representing an ESTree-compliant AST node.
+     * @param context - An object containing variables and values to be used during evaluation.
+     * @returns The result of the evaluation.
+     */
+    export namespace evaluate {
+        function sync<ASTNode>(
+            expression: ASTNode,
+            context: object,
+            options?: EvalESTreeExpressionOptions
+        ): any;
+    }
+}

packages/fonts/.gitignore

@@ -0,0 +1,2 @@
+dist/
+src/data/*.json

packages/fonts/CHANGELOG.md

@@ -0,0 +1,7 @@
+# @gitbook/fonts
+
+## 0.1.0
+
+### Minor Changes
+
+- fbfcca5: Initial version of the package

packages/fonts/README.md

@@ -0,0 +1,3 @@
+# `@gitbook/fonts`
+
+Utilities to lookup default fonts supported by GitBook.

packages/fonts/bin/generate.ts

@@ -0,0 +1,91 @@
+import fs from 'node:fs/promises';
+import path from 'node:path';
+
+import { APIv2 } from 'google-font-metadata';
+
+import { CustomizationDefaultFont } from '@gitbook/api';
+
+import type { FontDefinitions } from '../src/types';
+
+const googleFontsMap: { [fontName in CustomizationDefaultFont]: string } = {
+    [CustomizationDefaultFont.Inter]: 'inter',
+    [CustomizationDefaultFont.FiraSans]: 'fira-sans-extra-condensed',
+    [CustomizationDefaultFont.IBMPlexSerif]: 'ibm-plex-serif',
+    [CustomizationDefaultFont.Lato]: 'lato',
+    [CustomizationDefaultFont.Merriweather]: 'merriweather',
+    [CustomizationDefaultFont.NotoSans]: 'noto-sans',
+    [CustomizationDefaultFont.OpenSans]: 'open-sans',
+    [CustomizationDefaultFont.Overpass]: 'overpass',
+    [CustomizationDefaultFont.Poppins]: 'poppins',
+    [CustomizationDefaultFont.Raleway]: 'raleway',
+    [CustomizationDefaultFont.Roboto]: 'roboto',
+    [CustomizationDefaultFont.RobotoSlab]: 'roboto-slab',
+    [CustomizationDefaultFont.SourceSansPro]: 'source-sans-3',
+    [CustomizationDefaultFont.Ubuntu]: 'ubuntu',
+    [CustomizationDefaultFont.ABCFavorit]: 'inter',
+};
+
+/**
+ * Scripts to generate the list of all icons.
+ */
+async function main() {
+    // @ts-expect-error - we build the object
+    const output: FontDefinitions = {};
+
+    for (const font of Object.values(CustomizationDefaultFont)) {
+        const googleFontName = googleFontsMap[font];
+        const fontMetadata = APIv2[googleFontName.toLowerCase()];
+        if (!fontMetadata) {
+            throw new Error(`Font ${googleFontName} not found`);
+        }
+
+        output[font] = {
+            font: googleFontName,
+            unicodeRange: fontMetadata.unicodeRange,
+            variants: {
+                '400': {},
+                '700': {},
+            },
+        };
+
+        Object.keys(output[font].variants).forEach((weight) => {
+            const variants = fontMetadata.variants[weight];
+            const normalVariant = variants.normal;
+            if (!normalVariant) {
+                throw new Error(`Font ${googleFontName} has no normal variant`);
+            }
+
+            output[font].variants[weight] = {};
+            Object.entries(normalVariant).forEach(([script, url]) => {
+                output[font].variants[weight][script] = url.url.woff;
+            });
+        });
+    }
+
+    await writeDataFile('fonts', JSON.stringify(output, null, 2));
+}
+
+/**
+ * We write both in dist and src as the build process might have happen already
+ * and tsc doesn't copy the files.
+ */
+async function writeDataFile(name, content) {
+    const srcData = path.resolve(__dirname, '../src/data');
+    const distData = path.resolve(__dirname, '../dist/data');
+
+    // Ensure the directories exists
+    await Promise.all([
+        fs.mkdir(srcData, { recursive: true }),
+        fs.mkdir(distData, { recursive: true }),
+    ]);
+
+    await Promise.all([
+        fs.writeFile(path.resolve(srcData, `${name}.json`), content),
+        fs.writeFile(path.resolve(distData, `${name}.json`), content),
+    ]);
+}
+
+main().catch((error) => {
+    console.error(`Error generating icons list: ${error}`);
+    process.exit(1);
+});

packages/fonts/package.json

@@ -0,0 +1,31 @@
+{
+    "name": "@gitbook/fonts",
+    "type": "module",
+    "exports": {
+        ".": {
+            "types": "./dist/index.d.ts",
+            "development": "./src/index.ts",
+            "default": "./dist/index.js"
+        }
+    },
+    "version": "0.1.0",
+    "dependencies": {
+        "@gitbook/api": "catalog:"
+    },
+    "devDependencies": {
+        "google-font-metadata": "^6.0.3",
+        "typescript": "^5.5.3"
+    },
+    "scripts": {
+        "generate": "bun ./bin/generate.js",
+        "build": "tsc --project tsconfig.build.json",
+        "typecheck": "tsc --noEmit",
+        "dev": "tsc -w",
+        "clean": "rm -rf ./dist && rm -rf ./src/data",
+        "unit": "bun test"
+    },
+    "files": ["dist", "src", "bin", "README.md", "CHANGELOG.md"],
+    "engines": {
+        "node": ">=20.0.0"
+    }
+}

packages/fonts/src/__snapshots__/getDefaultFont.test.ts.snap

@@ -0,0 +1,57 @@
+// Bun Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`getDefaultFont should return correct object for Latin text 1`] = `
+{
+  "font": "Inter",
+  "url": "https://fonts.gstatic.com/s/inter/v18/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuLyfAZ9hjp-Ek-_0ew.woff",
+}
+`;
+
+exports[`getDefaultFont should return correct object for Cyrillic text 1`] = `
+{
+  "font": "Inter",
+  "url": "https://fonts.gstatic.com/s/inter/v18/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuLyfAZthjp-Ek-_0ewmM.woff",
+}
+`;
+
+exports[`getDefaultFont should return correct object for Greek text 1`] = `
+{
+  "font": "Inter",
+  "url": "https://fonts.gstatic.com/s/inter/v18/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuLyfAZxhjp-Ek-_0ewmM.woff",
+}
+`;
+
+exports[`getDefaultFont should handle mixed script text 1`] = `
+{
+  "font": "Inter",
+  "url": "https://fonts.gstatic.com/s/inter/v18/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuLyfAZthjp-Ek-_0ewmM.woff",
+}
+`;
+
+exports[`getDefaultFont should handle different font weights: regular 1`] = `
+{
+  "font": "Inter",
+  "url": "https://fonts.gstatic.com/s/inter/v18/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuLyfAZ9hjp-Ek-_0ew.woff",
+}
+`;
+
+exports[`getDefaultFont should handle different font weights: bold 1`] = `
+{
+  "font": "Inter",
+  "url": "https://fonts.gstatic.com/s/inter/v18/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuFuYAZ9hjp-Ek-_0ew.woff",
+}
+`;
+
+exports[`getDefaultFont should handle different fonts: inter 1`] = `
+{
+  "font": "Inter",
+  "url": "https://fonts.gstatic.com/s/inter/v18/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuLyfAZ9hjp-Ek-_0ew.woff",
+}
+`;
+
+exports[`getDefaultFont should handle different fonts: roboto 1`] = `
+{
+  "font": "Roboto",
+  "url": "https://fonts.gstatic.com/s/roboto/v32/KFOmCnqEu92Fr1Mu4mxMKTU1Kg.woff",
+}
+`;

packages/fonts/src/fonts.ts

@@ -0,0 +1,5 @@
+import type { FontDefinitions } from './types';
+
+import rawFonts from './data/fonts.json' with { type: 'json' };
+
+export const fonts: FontDefinitions = rawFonts;

packages/fonts/src/getDefaultFont.test.ts

@@ -0,0 +1,119 @@
+import { describe, expect, it } from 'bun:test';
+import { CustomizationDefaultFont } from '@gitbook/api';
+import { getDefaultFont } from './getDefaultFont';
+
+describe('getDefaultFont', () => {
+    it('should return null for invalid font', () => {
+        const result = getDefaultFont({
+            font: 'invalid-font' as CustomizationDefaultFont,
+            text: 'Hello',
+            weight: 400,
+        });
+        expect(result).toBeNull();
+    });
+
+    it('should return null for invalid weight', () => {
+        const result = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Hello',
+            weight: 999 as any,
+        });
+        expect(result).toBeNull();
+    });
+
+    it('should return null for text not supported by any script', () => {
+        const result = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: '😀', // Emoji not supported by Inter
+            weight: 400,
+        });
+        expect(result).toBeNull();
+    });
+
+    it('should return correct object for Latin text', () => {
+        const result = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Hello World',
+            weight: 400,
+        });
+        expect(result).not.toBeNull();
+        expect(result?.font).toBe(CustomizationDefaultFont.Inter);
+        expect(result).toMatchSnapshot();
+    });
+
+    it('should return correct object for Cyrillic text', () => {
+        const result = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Привет мир',
+            weight: 400,
+        });
+        expect(result).not.toBeNull();
+        expect(result?.font).toBe(CustomizationDefaultFont.Inter);
+        expect(result).toMatchSnapshot();
+    });
+
+    it('should return correct object for Greek text', () => {
+        const result = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Γεια σας',
+            weight: 400,
+        });
+        expect(result).not.toBeNull();
+        expect(result?.font).toBe(CustomizationDefaultFont.Inter);
+        expect(result).toMatchSnapshot();
+    });
+
+    it('should handle mixed script text', () => {
+        const result = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Hello Привет',
+            weight: 400,
+        });
+        expect(result).not.toBeNull();
+        expect(result?.font).toBe(CustomizationDefaultFont.Inter);
+        expect(result).toMatchSnapshot();
+    });
+
+    it('should handle different font weights', () => {
+        const regular = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Hello',
+            weight: 400,
+        });
+        const bold = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Hello',
+            weight: 700,
+        });
+        expect(regular).not.toBeNull();
+        expect(bold).not.toBeNull();
+        expect(regular).toMatchSnapshot('regular');
+        expect(bold).toMatchSnapshot('bold');
+    });
+
+    it('should handle empty string', () => {
+        const result = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: '',
+            weight: 400,
+        });
+        expect(result).toBeNull();
+    });
+
+    it('should handle different fonts', () => {
+        const inter = getDefaultFont({
+            font: CustomizationDefaultFont.Inter,
+            text: 'Hello',
+            weight: 400,
+        });
+        const roboto = getDefaultFont({
+            font: CustomizationDefaultFont.Roboto,
+            text: 'Hello',
+            weight: 400,
+        });
+        expect(inter).not.toBeNull();
+        expect(roboto).not.toBeNull();
+        expect(inter).toMatchSnapshot('inter');
+        expect(roboto).toMatchSnapshot('roboto');
+    });
+});

packages/fonts/src/getDefaultFont.ts

@@ -0,0 +1,112 @@
+import type { CustomizationDefaultFont } from '@gitbook/api';
+import { fonts } from './fonts';
+import type { FontWeight } from './types';
+
+/**
+ * Get the URL to load a font for a text.
+ */
+export function getDefaultFont(input: {
+    /**
+     * GitBook font to use.
+     */
+    font: CustomizationDefaultFont;
+
+    /**
+     * Text to display with the font.
+     */
+    text: string;
+
+    /**
+     * Font weight to use.
+     */
+    weight: FontWeight;
+}): { font: string; url: string } | null {
+    if (!input.text.trim()) {
+        return null;
+    }
+
+    const fontDefinition = fonts[input.font];
+    if (!fontDefinition) {
+        return null;
+    }
+
+    const variant = fontDefinition.variants[`${input.weight}`];
+    if (!variant) {
+        return null;
+    }
+
+    const script = getBestUnicodeRange(input.text, fontDefinition.unicodeRange);
+    if (!script) {
+        return null;
+    }
+
+    return variant[script]
+        ? {
+              font: input.font,
+              url: variant[script],
+          }
+        : null;
+}
+
+/**
+ * Determine which named @font-face unicode-range covers
+ * the greatest share of the characters in `text`.
+ *
+ * @param text   The text you want to inspect.
+ * @param ranges An object whose keys are range names and whose
+ *               values are CSS-style comma-separated unicode-range
+ *               declarations (e.g. "U+0370-03FF,U+1F00-1FFF").
+ * @returns      The key of the best-matching range, or `null`
+ *               when nothing matches at all.
+ */
+function getBestUnicodeRange(text: string, ranges: Record<string, string>): string | null {
+    // ---------- helper: parse "U+XXXX" or "U+XXXX-YYYY" ----------
+    const parseOne = (token: string): [number, number] | null => {
+        token = token.trim().toUpperCase();
+        if (!token.startsWith('U+')) return null;
+
+        const body = token.slice(2); // drop "U+"
+        const [startHex, endHex] = body.split('-');
+        const start = Number.parseInt(startHex!, 16);
+        const end = endHex ? Number.parseInt(endHex, 16) : start;
+
+        if (Number.isNaN(start) || Number.isNaN(end) || end < start) return null;
+        return [start, end];
+    };
+
+    // ---------- helper: build lookup table ----------
+    const parsed: Record<string, [number, number][]> = {};
+    for (const [label, list] of Object.entries(ranges)) {
+        parsed[label] = list
+            .split(',')
+            .map(parseOne)
+            .filter((x): x is [number, number] => x !== null);
+    }
+
+    // ---------- tally code-point hits ----------
+    const hits: Record<string, number> = Object.fromEntries(Object.keys(parsed).map((k) => [k, 0]));
+
+    for (let i = 0; i < text.length; ) {
+        const cp = text.codePointAt(i)!;
+        i += cp > 0xffff ? 2 : 1; // advance by 1 UTF-16 code-unit (or 2 for surrogates)
+
+        for (const [label, rangesArr] of Object.entries(parsed)) {
+            if (rangesArr.some(([lo, hi]) => cp >= lo && cp <= hi)) {
+                hits[label]!++;
+            }
+        }
+    }
+
+    // ---------- choose the "best" ----------
+    let winner: string | null = null;
+    let maxCount = 0;
+
+    for (const [label, count] of Object.entries(hits)) {
+        if (count > maxCount) {
+            maxCount = count;
+            winner = label;
+        }
+    }
+
+    return maxCount > 0 ? winner : null;
+}

packages/fonts/src/index.ts

@@ -0,0 +1,2 @@
+export * from './getDefaultFont';
+export * from './types';

packages/fonts/src/types.ts

@@ -0,0 +1,17 @@
+import type { CustomizationDefaultFont } from '@gitbook/api';
+
+export type FontWeight = 400 | 700;
+
+export type FontDefinition = {
+    font: string;
+    unicodeRange: {
+        [script: string]: string;
+    };
+    variants: {
+        [weight in string]: {
+            [script: string]: string;
+        };
+    };
+};
+
+export type FontDefinitions = { [fontName in CustomizationDefaultFont]: FontDefinition };

packages/fonts/tsconfig.build.json

@@ -0,0 +1,4 @@
+{
+    "extends": "./tsconfig.json",
+    "exclude": ["node_modules", "src/**/*.test.ts"]
+}

packages/fonts/tsconfig.json

@@ -0,0 +1,25 @@
+{
+    "compilerOptions": {
+        "lib": ["es2023"],
+        "module": "ESNext",
+        "target": "es2022",
+        "strict": true,
+        "noUncheckedIndexedAccess": true,
+        "esModuleInterop": true,
+        "skipLibCheck": true,
+        "moduleResolution": "bundler",
+        "allowJs": true,
+        "noEmit": false,
+        "declaration": true,
+        "outDir": "dist",
+        "resolveJsonModule": true,
+        "isolatedModules": true,
+        "jsx": "react-jsx",
+        "incremental": true,
+        "types": [
+            "bun-types" // add Bun global
+        ]
+    },
+    "include": ["src/**/*.ts"],
+    "exclude": ["node_modules"]
+}

packages/fonts/turbo.json

@@ -0,0 +1,9 @@
+{
+    "extends": ["//"],
+    "tasks": {
+        "generate": {
+            "inputs": ["bin/**/*", "package.json"],
+            "outputs": ["src/data/*.json", "dist/data/*.json"]
+        }
+    }
+}

packages/gitbook-v2/.gitignore

@@ -1,11 +0,0 @@
-# next.js
-/.next/
-
-# vercel
-.vercel
-
-# cloudflare
-.open-next
-
-# Symbolic links
-public

packages/gitbook-v2/CHANGELOG.md

@@ -1,62 +0,0 @@
-# gitbook-v2
-
-## 0.2.5
-
-### Patch Changes
-
-- Updated dependencies [77397ca]
-  - @gitbook/cache-tags@0.3.1
-
-## 0.2.4
-
-### Patch Changes
-
-- 4234289: Fix incoming URL for requests that were proxied
-- Updated dependencies [116575c]
-  - @gitbook/cache-tags@0.3.0
-
-## 0.2.3
-
-### Patch Changes
-
-- 5b2bf82: Use stable site URL data for route rewrite in the middleware
-
-## 0.2.2
-
-### Patch Changes
-
-- 54ee014: Add initial support for loading custom fonts
-- bba2e52: Fix site redirects when it includes a section/variant path
-
-## 0.2.1
-
-### Patch Changes
-
-- Updated dependencies [f32bf1f]
-  - @gitbook/cache-tags@0.2.0
-
-## 0.2.0
-
-### Minor Changes
-
-- 76c7974: Add route to revalidate cached data
-
-## 0.1.2
-
-### Patch Changes
-
-- 05ffd0e: Improving data cache management for computed content
-- Updated dependencies [05ffd0e]
-  - @gitbook/cache-tags@0.1.0
-
-## 0.1.1
-
-### Patch Changes
-
-- 3e11678: fix: lost section groups
-
-## 0.1.0
-
-### Minor Changes
-
-- cfccc44: Setup structure and deployment for new version

packages/gitbook-v2/next-env.d.ts

@@ -1,5 +0,0 @@
-/// <reference types="next" />
-/// <reference types="next/image-types/global" />
-
-// NOTE: This file should not be edited
-// see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

packages/gitbook-v2/open-next.config.ts

@@ -1,18 +0,0 @@
-import { defineCloudflareConfig } from '@opennextjs/cloudflare';
-import r2IncrementalCache from '@opennextjs/cloudflare/overrides/incremental-cache/r2-incremental-cache';
-import { withRegionalCache } from '@opennextjs/cloudflare/overrides/incremental-cache/regional-cache';
-import doQueue from '@opennextjs/cloudflare/overrides/queue/do-queue';
-import doShardedTagCache from '@opennextjs/cloudflare/overrides/tag-cache/do-sharded-tag-cache';
-
-export default defineCloudflareConfig({
-    incrementalCache: withRegionalCache(r2IncrementalCache, { mode: 'long-lived' }),
-    tagCache: doShardedTagCache({
-        baseShardSize: 12,
-        regionalCache: true,
-        shardReplication: {
-            numberOfSoftReplicas: 2,
-            numberOfHardReplicas: 1,
-        },
-    }),
-    queue: doQueue,
-});

packages/gitbook-v2/package.json

@@ -1,36 +0,0 @@
-{
-    "name": "gitbook-v2",
-    "version": "0.2.5",
-    "private": true,
-    "dependencies": {
-        "next": "canary",
-        "react": "^19.0.0",
-        "react-dom": "^19.0.0",
-        "@gitbook/api": "*",
-        "@gitbook/cache-tags": "workspace:*",
-        "@sindresorhus/fnv1a": "^3.1.0",
-        "server-only": "^0.0.1",
-        "warn-once": "^0.1.1",
-        "rison": "^0.1.1",
-        "jwt-decode": "^4.0.0",
-        "assert-never": "^1.2.1"
-    },
-    "devDependencies": {
-        "gitbook": "*",
-        "@opennextjs/cloudflare": "^1.0.0-beta.3",
-        "@types/rison": "^0.0.9",
-        "tailwindcss": "^3.4.0",
-        "postcss": "^8"
-    },
-    "scripts": {
-        "generate": "rm -rf ./public && cp -r ../gitbook/public ./public",
-        "dev:v2": "env-cmd --silent -f ../../.env.local next --turbopack",
-        "build": "next build",
-        "build:v2": "next build",
-        "start": "next start",
-        "build:v2:cloudflare": "opennextjs-cloudflare build",
-        "dev:v2:cloudflare": "wrangler dev --port 8771",
-        "unit": "bun test",
-        "typecheck": "tsc --noEmit"
-    }
-}

packages/gitbook-v2/postcss.config.js

@@ -1,6 +0,0 @@
-module.exports = {
-    plugins: {
-        tailwindcss: {},
-        autoprefixer: {},
-    },
-};

packages/gitbook-v2/src/app/~space/[spaceId]/~/changes/[changeRequestId]/~gitbook/pdf/layout.tsx

@@ -1,2 +0,0 @@
-import RootLayout from '@v2/app/~space/[spaceId]/~gitbook/pdf/layout';
-export default RootLayout;

packages/gitbook-v2/src/app/~space/[spaceId]/~/changes/[changeRequestId]/~gitbook/pdf/page.tsx

@@ -1,4 +0,0 @@
-import PDFPage, { generateMetadata } from '@v2/app/~space/[spaceId]/~gitbook/pdf/page';
-
-export default PDFPage;
-export { generateMetadata };

packages/gitbook-v2/src/app/~space/[spaceId]/~/revisions/[changeRequestId]/~gitbook/pdf/layout.tsx

@@ -1,2 +0,0 @@
-import RootLayout from '@v2/app/~space/[spaceId]/~gitbook/pdf/layout';
-export default RootLayout;

packages/gitbook-v2/src/app/~space/[spaceId]/~/revisions/[changeRequestId]/~gitbook/pdf/page.tsx

@@ -1,4 +0,0 @@
-import PDFPage, { generateMetadata } from '@v2/app/~space/[spaceId]/~gitbook/pdf/page';
-
-export default PDFPage;
-export { generateMetadata };