changeset

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.agents/skills/write-pr-description/SKILL.md

@@ -0,0 +1,48 @@
+---
+name: write-pr-description
+description: Write a concise, product-focused PR description from the changes and available discussion. Use when asked for a PR summary or description.
+---
+
+# Write a PR description
+
+Read the full branch diff and commit history against the PR's base branch, not just the latest commit. Use the PR discussion and linked issues for context when available. The PR's changes are the source of truth for what ships if an issue describes something different.
+
+Write for contributors and reviewers who may not know the area. Lead with what changes, prefer user or product impact when supported, and include implementation details only when they help review. Keep the proposed changes short, using bullets only when useful.
+
+Include relevant validation and screenshots when available. Do not claim checks passed unless they ran. Use only information appropriate for a public repository; do not copy private issue details or customer information into the description.
+
+## Template and changelog
+
+Read `.github/pull_request_template.md` immediately before writing. Preserve its required section names and order. Include `Proposed changes` and `Changelog`; omit `Demo` when there is nothing to show. Add optional `Context` before `Changelog` only when it meets the rule below.
+
+Write a short changelog entry describing what shipped. Use `[Feature]` for user-facing additions or improvements, `[Fix]` for user-facing bug fixes, and `[Chore]` for internal maintenance. For features and fixes, say what users can do or what no longer goes wrong in plain words. Keep chores useful to teammates without inventing user impact. Remove unused examples and placeholders. Usually one entry is enough; use more only for distinct changes. The PR changelog does not replace any changeset required by `AGENTS.md`.
+
+## Optional context
+
+Write `Proposed changes` and `Changelog` first. Add `Context` only when it tells someone unfamiliar with the area something material that the changelog does not. `Problem` names a concrete failure or limitation supported by the PR or discussion. `Outcome` names what this PR delivers at its actual scope. Omit the section if either field would repeat the changelog, describe only implementation, or guess at an impact.
+
+```markdown
+## Context
+
+**Problem:** <concrete failure or limitation>
+
+**Outcome:** <result delivered by this PR>
+```
+
+Keep each field to 1–2 short, non-technical sentences. Prefer user or product impact when supported. For infrastructure changes, explain the failure or limitation they caused. Do not invent an actor, customer segment, ownership, or impact, or force the change into a user story. Do not turn a preparatory change into a claim that the whole workflow is fixed. Keep the roles distinct: `Context` explains why this matters, `Changelog` says what shipped, and `Proposed changes` can explain implementation.
+
+Examples:
+
+- A dependency bump with no demonstrated user effect needs no `Context`.
+- If creating the first change request leaves the user on an empty screen, say that it now opens after creation. Leave the animation-listener details in `Proposed changes`.
+- If a PR indexes links for later checks, describe the indexing result. Do not claim every link has already been checked.
+
+## Writing pass
+
+- Use plain words and direct verbs: "use" instead of "leverage", "help" instead of "facilitate". Prefer active voice when the actor is known.
+- Name the concrete behavior instead of saying "improves the experience" or "makes it more robust". Support performance claims with measurements.
+- Cut filler, promotional language, and generic conclusions. If a sentence could fit almost any PR, make it specific or delete it.
+- Keep one idea per sentence and use consistent names. Remove redundant hedging without hiding real uncertainty.
+- Avoid "not just X, but Y", forced groups of three, em dashes, decorative emojis, and unnecessary bold text.
+
+Return the description in a Markdown code block unless asked to update the PR. When asked to update it, apply the description with `gh pr edit` using a body file.

.changeset/bold-bugs-hug.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-OpenAPI styling tweaks

.changeset/bump-next-16-4-3.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Bump Next.js to 16.4.3, keeping the dev-mode OOM patch.

.changeset/clever-apes-check.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Prevent form submission during IME composition

.changeset/cool-squids-own.md

@@ -1,6 +0,0 @@
----
-"gitbook": minor
-"@gitbook/react-openapi": patch
----
-
-Support code themes customization

.changeset/curly-eels-carry.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Add sidesheet component, use it for TOC and AIChat

.changeset/fast-planets-pay.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Set <html lang> based on translated language

.changeset/fluffy-lines-type.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Support social links

.changeset/forty-ads-attend.md

@@ -1,5 +0,0 @@
----
-"@gitbook/embed": patch
----
-
-Fix signed JWT token usage

.changeset/four-clowns-begin.md

@@ -1,5 +0,0 @@
----
-"@gitbook/react-openapi": patch
----
-
-Fix OpenAPI example not showing

.changeset/full-ways-cross.md

@@ -1,5 +0,0 @@
----
-"gitbook": minor
----
-
-Serve a markdown version of the page when the "Accept" header contains "text/markdown".

.changeset/funky-actors-lie.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Align styling of PageLinkItem and PageDocumentItem

.changeset/gentle-lines-serve.md

@@ -1,5 +0,0 @@
----
-"@gitbook/openapi-parser": patch
----
-
-Update scalar dependencies.

.changeset/great-animals-end.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Support `defaultExpanded` in Expandable block

.changeset/grumpy-dogs-cough.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Better conditional display of page actions

.changeset/humble-insects-speak.md

@@ -1,5 +0,0 @@
----
-"@gitbook/react-openapi": patch
----
-
-Improve OpenAPI server URL validation

.changeset/late-emus-jog.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Header & TOC tweaks

.changeset/lazy-inline-expressions.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Load the inline expression runtime only on pages whose code blocks or text use expressions, so other pages ship less JavaScript.

.changeset/llms-full-size-pagination.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Split llms-full.txt into parts by size so large sites no longer fail with "content too large"

.changeset/mcp-get-page-redirects.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Follow site and space redirects when the MCP getPage tool resolves a page URL.

.changeset/native-external-link-clicks.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Let analytics tools like GA4 track outbound link clicks by using native link navigation.

.changeset/public-comics-push.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Fix ordered list item index calculation

.changeset/quick-colts-trade.md

@@ -1,5 +0,0 @@
----
-"@gitbook/react-openapi": patch
----
-
-Fix Scalar Try it button justification

.changeset/rare-ties-find.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Standardise toggle chevrons across the app

.changeset/resolve-full-url.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Resolve the published content with the full URL in a single lookup and always send the visitor country.

.changeset/rss-feed-html-content.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Keep lists, paragraphs and code blocks as HTML in Updates RSS feeds, instead of running all the text together

.changeset/smooth-glasses-see.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Fix rendering of images in reusable content from an external space with the new dereferencing in the API.

.changeset/some-grapes-jump.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Grow InlineActionButton to take available width on line

.changeset/ten-snails-bet.md

@@ -1,5 +0,0 @@
----
-"@gitbook/icons": patch
----
-
-Simplify installation by using public fontawesome mirror.

.changeset/tiny-rockets-obey.md

@@ -1,6 +0,0 @@
----
-"@gitbook/browser-types": patch
-"gitbook": patch
----
-
-Add support for custom cookie banner registration

.changeset/tough-dryers-rule.md

@@ -1,5 +0,0 @@
----
-"gitbook": patch
----
-
-Better handle huge section groups

.changeset/vast-emus-cheer.md

@@ -1,6 +0,0 @@
----
-"gitbook": patch
-"@gitbook/embed": patch
----
-
-Fix Embed options in React

.changeset/yellow-fans-hunt.md

@@ -1,5 +0,0 @@
----
-"@gitbook/react-openapi": patch
----
-
-Add OpenAPI 3.1 nullable array support

.claude/launch.json

@@ -0,0 +1,12 @@
+{
+    "version": "0.0.1",
+    "configurations": [
+        {
+            "name": "🚀 Dev server",
+            "runtimeExecutable": "sh",
+            "runtimeArgs": ["-c", "bun install && bun dev"],
+            "port": 3000,
+            "autoPort": false
+        }
+    ]
+}

.claude/skills/write-pr-description

@@ -0,0 +1 @@
+../../.agents/skills/write-pr-description

.codex/skills/write-pr-description

@@ -0,0 +1 @@
+../../.agents/skills/write-pr-description

.editorconfig

@@ -0,0 +1,10 @@
+# Stop editors from looking for .editorconfig files in parent directories.
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_style = space
+indent_size = 4
+insert_final_newline = true
+max_line_length = 100

.github/CODEOWNERS

@@ -1,3 +0,0 @@
-# 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

@@ -1,110 +1,89 @@
-# Welcome to GitBook's contributing guide!
+# Contributing to GitBook
 
-> _For help, support, feature requests, and product questions - head to our [GitHub Community](https://github.com/orgs/GitbookIO/discussions) 🤖_
+> _For help, support and product questions, head to our [GitHub Community](https://github.com/orgs/GitbookIO/discussions)._
 
-Thank you for investing your time in contributing to GitBook. Any contribution you make will be reviewed by our team. In this guide, you'll learn the different ways you can contribute.
+Thanks for helping make GitBook better. This repository holds the open source renderer behind every published GitBook site, and the team reads everything that comes in here.
 
-## Types of Contributions
+## Ways to contribute
 
-This repository contains code related to the rendering engine of GitBook's published content. Depending on what you'd like to contribute to, head to the section below to find the necessary steps.
+-   **Open an issue.** Report a bug, suggest a feature, or tell us when something feels off. This is the most useful thing you can do.
+-   **Join the conversation.** Share ideas and help others in [GitHub Community](https://github.com/orgs/GitbookIO/discussions).
+-   **Build with GitBook.** Publish your docs, try new features early, and tell us what works and what doesn't.
 
-### Add a feature
+## Issues instead of pull requests
 
-Because this portion of GitBook is open source and available for you to use - if you think you can provide extra value through a new feature - you're welcome to add it! If you plan to distribute the code, keep the source code public to comply with GNU GPLv3. To clone in a private repository, you must first acquire a [commercial license](https://www.gitbook.com/pricing).
+Pull requests are limited to the GitBook team. If you've found a bug or want something to change, please [open an issue](https://github.com/GitbookIO/gitbook/issues/new/choose) instead.
 
-### Create a new issue
+This isn't because we don't want your help. Every change here ships to every published GitBook site, so we need to own each one from start to finish. A clear issue often helps us more than a pull request: it tells us what's wrong and why, and lets us fix it in a way that fits the rest of the codebase.
 
-If you spot a problem within a repository, [search if an issue already exists](https://docs.github.com/en/github/searching-for-information-on-github/searching-on-github/searching-issues-and-pull-requests#search-by-the-title-body-or-comments). If a related issue doesn't exist, you can open a new issue here!Please make sure any added issues are
+A good issue includes:
 
--   Descriptive
--   Thoughtful
--   Organized
+-   What you expected to happen, and what happened instead
+-   A link to a published GitBook site that shows the problem, if you have one
+-   Steps to reproduce it, plus screenshots or a recording for anything visual
+-   Your browser and OS, if it looks like it might matter
 
-We recommend adding as many relevant links, minimal reproductions of the issue, and other materials that will help our team solve the issue fast.
+Before opening one, [search existing issues](https://github.com/GitbookIO/gitbook/issues). If someone has already reported it, add a 👍 or any extra details you have.
 
-### Solve an issue
+Already fixed it in your fork? Link the branch or commit in your issue. We may open a pull request from it, and your commits keep your name.
 
-If you're interested in solving an issue in our repository, start by scanning through it's exisiting issues to find one that you're interested in working on. If you find an issue to work on, you are welcome to open a PR with a fix. See the following sections below for more information on contributing for specific sections.
+If you open a pull request anyway, we'll close it and point you here. Nothing personal, and we'd still love the issue.
 
-### Documentation
+## Reach out
 
-The official documentation on GitBook open can be found directly in this Readme. Any updates or changes you would like to make, you can make directly to the README of this repository.
+Not sure if it's a bug? Have a half-formed idea? Open an issue or start a [discussion](https://github.com/orgs/GitbookIO/discussions) anyway. We'd much rather hear from you than not, and no report is too small.
 
-## Contributing
+Spotted a wrong or missing translation? Open an issue with the string and the wording you'd suggest.
 
-### Make changes locally
+## Using AI
 
-Any contribution you make can be made to the code located in this repository. In order to contribute, you'll need to start off of a local version of this repository.
+You're welcome to use AI to help you write an issue. Please read and check what it produces before you post: reports that are long, vague or unverified take time away from fixing real problems, and we may close them without a reply.
 
-#### 1. Fork the repository
+## Running locally
 
-##### Using GitHub Desktop:
+You don't need a local setup to open an issue, but it can help you reproduce a problem or self-host the renderer.
 
--   [Getting started with GitHub Desktop](https://docs.github.com/en/desktop/installing-and-configuring-github-desktop/getting-started-with-github-desktop) will guide you through setting up Desktop.
--   Once Desktop is set up, you can use it to [fork the repo](https://docs.github.com/en/desktop/contributing-and-collaborating-using-github-desktop/cloning-and-forking-repositories-from-github-desktop)!
+### Prerequisites
 
-##### Using the command line:
+-   [Node.js](https://nodejs.org/en) (see "engines" in `package.json`)
+-   [Bun](https://bun.sh/) (see "packageManager" in `package.json`)
 
--   [Fork the repo](https://docs.github.com/en/github/getting-started-with-github/fork-a-repo#fork-an-example-repository) so that you can make your changes without affecting the original project until you're ready to merge them.
+### Setup
 
-#### 2. Create a working branch and start with your changes
+1. Use the project's version of Node:
 
-After forking this repository, you'll want to [create a branch](https://docs.github.com/en/issues/tracking-your-work-with-issues/creating-a-branch-for-an-issue) to work off of.
-
-#### 3. Install dependencies and run the project locally
-
-##### Prerequisites:
-
-- [Node.js](https://nodejs.org/en) (see "engines" in `package.json`)
-- [Bun](https://bun.sh/) (see "packageManager" in `package.json`)
-
-##### Setup steps:
-
-1. Ensure you are using the project's version of Node:
 ```bash
 nvm use
 ```
 
-2. Install dependencies using Bun:
+2. Install dependencies:
+
 ```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
+Other commands:
 
-#### 4. Preview your changes
+-   `bun lint`: Lint the code using Oxlint
+-   `bun lint:fix`: Automatically fix lint issues using Oxlint
+-   `bun format`: Format the code using Oxfmt
+-   `bun format:check`: Check formatting without changing files
+-   `bun typecheck`: Run TypeScript type checking
+-   `bun unit`: Run unit tests
+-   `bun e2e`: Run end-to-end tests
 
-When running the development server, published GitBook sites can be rendered through your local version at `http://localhost:3000/url`.
+### Preview a site
 
-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.
+With the development server running, any published GitBook site can be rendered through your local version at `http://localhost:3000/url/<published-url>`. For example, visit `http://localhost:3000/url/gitbook.com/docs` to see our own docs.
 
-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.
+The site must be [published publicly](https://gitbook.com/docs/published-documentation/publish-your-content-as-a-docs-site) to render locally.
 
-### Commit your update
+## License
 
-[Commit your changes](https://github.com/git-guides/git-commit) once you are happy with them. See [Atom's contributing guide](https://github.com/atom/atom/blob/master/CONTRIBUTING.md#git-commit-messages) to know how to use emoji for commit messages!
-
-Once your changes are ready, don't forget to self-review your code to double check that your chagnes are ready to be added.
-
-### Pull Request
-
-When you're finished with the changes, [create a pull request](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request), also known as a PR.
-
--   Don't forget to [link PR to issue](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue) if you are solving one.
--   Enable the checkbox to [allow maintainer edits](https://docs.github.com/en/github/collaborating-with-issues-and-pull-requests/allowing-changes-to-a-pull-request-branch-created-from-a-fork) so the branch can be updated for a merge. Once you submit your PR, a GitBook team member will review your proposal. We may ask questions or request for additional information.
--   We may ask for changes to be made before a PR can be merged, either using [suggested changes](https://docs.github.com/en/github/collaborating-with-issues-and-pull-requests/incorporating-feedback-in-your-pull-request) or pull request comments. You can apply suggested changes directly through the UI. You can make any other changes in your fork, then commit them to your branch.
--   As you update your PR and apply changes, mark each conversation as [resolved](https://docs.github.com/en/github/collaborating-with-issues-and-pull-requests/commenting-on-a-pull-request#resolving-conversations).
--   If you run into any merge issues, checkout this [git tutorial](https://lab.github.com/githubtraining/managing-merge-conflicts) to help you resolve merge conflicts and other issues.
-
-### Your PR is merged
-
-Congratulations 🎉 Thank you for your contribution! Once your PR is merged, your contributions will be publicly visible on the relevant repository.
+The renderer is distributed under the [GNU GPLv3 License](https://github.com/GitbookIO/gitbook/blob/main/LICENSE). If you distribute the code, you must keep the source code public. To use it in a private repository, you need a [commercial license](https://www.gitbook.com/pricing).

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

@@ -1,83 +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
+    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 }}
+    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: '4.43.0'
-            environment: ${{ inputs.environment }}
-            command: deployments status --config ./packages/gitbook/openNext/customWorkers/defaultWrangler.jsonc
+    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: '4.43.0'
+              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" >> $GITHUB_OUTPUT
+        # This step is used to get the version ID that is currently deployed to Cloudflare.
+        - id: extract_current_version
+          name: Extract current version
+          shell: bash
+          run: |
+              version_id=$(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: '4.43.0'
-            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
+        - 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: '4.43.0'
+              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: '4.43.0'
-            environment: ${{ inputs.environment }}
-            command: versions deploy ${{ inputs.middlewareVersionId }}@100% -y --config ./packages/gitbook/openNext/customWorkers/middlewareWrangler.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: '4.43.0'
+              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: '4.43.0'
-            environment: ${{ inputs.environment }}
-            command: versions deploy ${{ inputs.serverVersionId }}@100% -y --config ./packages/gitbook/openNext/customWorkers/defaultWrangler.jsonc
+        - name: Deploy server to Cloudflare at 100%
+          uses: cloudflare/wrangler-action@v3.14.0
+          with:
+              apiToken: ${{ inputs.apiToken }}
+              accountId: ${{ inputs.accountId }}
+              workingDirectory: ./
+              wranglerVersion: '4.43.0'
+              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 }}"
+        - name: Outputs
+          shell: bash
+          env:
+              DEPLOYMENT_URL: ${{ steps.deploy_middleware.outputs.deployment-url }}
+          run: |
+              echo "URL: ${{ steps.deploy_middleware.outputs.deployment-url }}"

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

@@ -1,34 +1,34 @@
 name: 'Deploy cloudflare'
 description: 'Deploy GitBook to Cloudflare'
 inputs:
-  opItem:
-    description: '1Password item to load secrets from'
-    required: true
-  opServiceAccount:
-    description: '1Password service account token'
-    required: true
-  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
-  deploy:
-    description: 'Deploy as main version for all traffic instead of uploading versions'
-    required: true
-  commitTag:
-    description: 'Commit branch to associate with the deployment'
-    required: true
-  commitMessage:
-    description: 'Commit message to associate with the deployment'
-    required: true
+    opItem:
+        description: '1Password item to load secrets from'
+        required: true
+    opServiceAccount:
+        description: '1Password service account token'
+        required: true
+    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
+    deploy:
+        description: 'Deploy as main version for all traffic instead of uploading versions'
+        required: true
+    commitTag:
+        description: 'Commit branch to associate with the deployment'
+        required: true
+    commitMessage:
+        description: 'Commit message to associate with the deployment'
+        required: true
 outputs:
-    deployment-url: 
-      description: "Deployment URL"
-      value: ${{ steps.upload_middleware.outputs.deployment-url }}
+    deployment-url:
+        description: 'Deployment URL'
+        value: ${{ steps.upload_middleware.outputs.deployment-url }}
 runs:
     using: 'composite'
     steps:
@@ -42,26 +42,34 @@ runs:
         - name: Load secret
           uses: 1password/load-secrets-action@v2
           env:
-            OP_SERVICE_ACCOUNT_TOKEN: ${{ inputs.opServiceAccount }}
-            GITBOOK_URL: ${{ inputs.opItem }}/GITBOOK_URL
-            GITBOOK_ICONS_URL: ${{ inputs.opItem }}/GITBOOK_ICONS_URL
-            GITBOOK_ICONS_TOKEN: ${{ inputs.opItem }}/GITBOOK_ICONS_TOKEN
-            NEXT_SERVER_ACTIONS_ENCRYPTION_KEY: ${{ inputs.opItem }}/NEXT_SERVER_ACTIONS_ENCRYPTION_KEY
-            GITBOOK_SECRET: ${{ inputs.opItem }}/GITBOOK_SECRET
-            GITBOOK_APP_URL: ${{ inputs.opItem }}/GITBOOK_APP_URL
-            GITBOOK_API_URL: ${{ inputs.opItem }}/GITBOOK_API_URL
-            GITBOOK_API_PUBLIC_URL: ${{ inputs.opItem }}/GITBOOK_API_PUBLIC_URL
-            GITBOOK_API_TOKEN: ${{ inputs.opItem }}/GITBOOK_API_TOKEN
-            GITBOOK_INTEGRATIONS_HOST: ${{ inputs.opItem }}/GITBOOK_INTEGRATIONS_HOST
-            GITBOOK_IMAGE_RESIZE_SIGNING_KEY: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_SIGNING_KEY
-            GITBOOK_IMAGE_RESIZE_URL: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_URL
-            GITBOOK_IMAGE_RESIZE_MODE: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_MODE
-            GITBOOK_ASSETS_PREFIX: ${{ inputs.opItem }}/GITBOOK_ASSETS_PREFIX
-            GITBOOK_FONTS_URL: ${{ inputs.opItem }}/GITBOOK_FONTS_URL
+              OP_SERVICE_ACCOUNT_TOKEN: ${{ inputs.opServiceAccount }}
+              GITBOOK_URL: ${{ inputs.opItem }}/GITBOOK_URL
+              GITBOOK_ICONS_URL: ${{ inputs.opItem }}/GITBOOK_ICONS_URL
+              GITBOOK_ICONS_TOKEN: ${{ inputs.opItem }}/GITBOOK_ICONS_TOKEN
+              NEXT_SERVER_ACTIONS_ENCRYPTION_KEY: ${{ inputs.opItem }}/NEXT_SERVER_ACTIONS_ENCRYPTION_KEY
+              GITBOOK_SECRET: ${{ inputs.opItem }}/GITBOOK_SECRET
+              GITBOOK_APP_URL: ${{ inputs.opItem }}/GITBOOK_APP_URL
+              GITBOOK_API_URL: ${{ inputs.opItem }}/GITBOOK_API_URL
+              GITBOOK_API_PUBLIC_URL: ${{ inputs.opItem }}/GITBOOK_API_PUBLIC_URL
+              GITBOOK_API_TOKEN: ${{ inputs.opItem }}/GITBOOK_API_TOKEN
+              GITBOOK_OAUTH_SERVER_URL: ${{ inputs.opItem }}/GITBOOK_OAUTH_SERVER_URL
+              GITBOOK_SITE_OAUTH_SIGNING_SECRET: ${{ inputs.opItem }}/GITBOOK_SITE_OAUTH_SIGNING_SECRET
+              GITBOOK_PREVIEW_BASE_URL: ${{ inputs.opItem }}/GITBOOK_PREVIEW_BASE_URL
+              GITBOOK_INTEGRATIONS_HOST: ${{ inputs.opItem }}/GITBOOK_INTEGRATIONS_HOST
+              GITBOOK_INTEGRATIONS_CONTENT_HOST: ${{ inputs.opItem }}/GITBOOK_INTEGRATIONS_CONTENT_HOST
+              GITBOOK_IMAGE_RESIZE_SIGNING_KEY: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_SIGNING_KEY
+              GITBOOK_IMAGE_RESIZE_URL: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_URL_2
+              GITBOOK_IMAGE_RESIZE_SALT: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_SALT
+              GITBOOK_IMAGE_RESIZE_MODE: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_MODE
+              GITBOOK_ASSETS_PREFIX: ${{ inputs.opItem }}/GITBOOK_ASSETS_PREFIX
+              GITBOOK_FONTS_URL: ${{ inputs.opItem }}/GITBOOK_FONTS_URL
         - name: Build worker
           run: bun run turbo build:cloudflare
           env:
-            GITBOOK_RUNTIME: cloudflare
+              GITBOOK_RUNTIME: cloudflare
+              GITBOOK_BLOCK_SEARCH_INDEXATION: ${{ inputs.environment == 'preview' && 'true' || '' }}
+              GITBOOK_ALLOW_CUSTOMIZATION_OVERRIDE: ${{ inputs.environment == 'preview' && 'true' || '' }}
+              GITBOOK_DISABLE_INSIGHTS: ${{ inputs.environment == 'preview' && 'true' || '' }}
           shell: bash
 
         - name: Upload the DO worker
@@ -107,7 +115,7 @@ runs:
               wranglerVersion: '4.43.0'
               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
@@ -128,11 +136,10 @@ runs:
               middlewareVersionId: ${{ steps.extract_middleware_version_id.outputs.version_id }}
               deploy: ${{ inputs.deploy }}
 
-
         - name: Outputs
           shell: bash
           env:
-            DEPLOYMENT_URL: ${{ steps.upload_middleware.outputs.deployment-url }}
+              DEPLOYMENT_URL: ${{ steps.upload_middleware.outputs.deployment-url }}
           run: |
               echo "URL: ${{ steps.upload_middleware.outputs.deployment-url }}"
-              echo "Output server: ${{ steps.upload_server.outputs.command-output }}"
+              echo "Output server: ${{ steps.upload_server.outputs.command-output }}"

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

@@ -1,28 +1,31 @@
 name: 'Deploy vercel'
 description: 'Deploy GitBook to Vercel'
 inputs:
-  vercelOrg:
-    description: 'Vercel organization'
-    required: true
-  vercelProject:
-    description: 'Vercel project'
-    required: true
-  vercelToken:
-    description: 'Vercel token'
-    required: true
-  opItem:
-    description: '1Password item to load secrets from'
-    required: true
-  opServiceAccount:
-    description: '1Password service account token'
-    required: true
-  environment:
-    description: 'Environment to deploy to'
-    required: true
+    vercelOrg:
+        description: 'Vercel organization'
+        required: true
+    vercelProject:
+        description: 'Vercel project'
+        required: true
+    vercelToken:
+        description: 'Vercel token'
+        required: true
+    opItem:
+        description: '1Password item to load secrets from'
+        required: true
+    opServiceAccount:
+        description: '1Password service account token'
+        required: true
+    environment:
+        description: 'Environment to deploy to'
+        required: true
+    headSha:
+        description: 'Git ref to deploy, used for the deploymentId'
+        required: false
 outputs:
-    deployment-url: 
-      description: "Deployment URL"
-      value: ${{ steps.deploy.outputs.deployment-url }}
+    deployment-url:
+        description: 'Deployment URL'
+        value: ${{ steps.deploy.outputs.deployment-url }}
 runs:
     using: 'composite'
     steps:
@@ -37,33 +40,52 @@ runs:
           run: bun run vercel pull --yes --environment=${{ inputs.environment }} --token=${{ inputs.vercelToken }}
           shell: bash
           env:
-            VERCEL_ORG_ID: ${{ inputs.vercelOrg }}
-            VERCEL_PROJECT_ID: ${{ inputs.vercelProject }}
+              VERCEL_ORG_ID: ${{ inputs.vercelOrg }}
+              VERCEL_PROJECT_ID: ${{ inputs.vercelProject }}
         - name: Load secret
           uses: 1password/load-secrets-action@v2
           env:
-            OP_SERVICE_ACCOUNT_TOKEN: ${{ inputs.opServiceAccount }}
-            GITBOOK_URL: ${{ inputs.opItem }}/GITBOOK_URL
-            GITBOOK_ICONS_URL: ${{ inputs.opItem }}/GITBOOK_ICONS_URL
-            GITBOOK_ICONS_TOKEN: ${{ inputs.opItem }}/GITBOOK_ICONS_TOKEN
-            GITBOOK_SECRET: ${{ inputs.opItem }}/GITBOOK_SECRET
-            GITBOOK_APP_URL: ${{ inputs.opItem }}/GITBOOK_APP_URL
-            GITBOOK_API_URL: ${{ inputs.opItem }}/GITBOOK_API_URL
-            GITBOOK_API_PUBLIC_URL: ${{ inputs.opItem }}/GITBOOK_API_PUBLIC_URL
-            GITBOOK_API_TOKEN: ${{ inputs.opItem }}/GITBOOK_API_TOKEN
-            GITBOOK_INTEGRATIONS_HOST: ${{ inputs.opItem }}/GITBOOK_INTEGRATIONS_HOST
-            GITBOOK_IMAGE_RESIZE_SIGNING_KEY: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_SIGNING_KEY
-            GITBOOK_IMAGE_RESIZE_URL: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_URL
-            GITBOOK_IMAGE_RESIZE_MODE: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_MODE
-            GITBOOK_ASSETS_PREFIX: ${{ inputs.opItem }}/GITBOOK_ASSETS_PREFIX
-            GITBOOK_FONTS_URL: ${{ inputs.opItem }}/GITBOOK_FONTS_URL
+              OP_SERVICE_ACCOUNT_TOKEN: ${{ inputs.opServiceAccount }}
+              GITBOOK_URL: ${{ inputs.opItem }}/GITBOOK_URL
+              GITBOOK_ICONS_URL: ${{ inputs.opItem }}/GITBOOK_ICONS_URL
+              GITBOOK_ICONS_TOKEN: ${{ inputs.opItem }}/GITBOOK_ICONS_TOKEN
+              GITBOOK_SECRET: ${{ inputs.opItem }}/GITBOOK_SECRET
+              GITBOOK_APP_URL: ${{ inputs.opItem }}/GITBOOK_APP_URL
+              GITBOOK_API_URL: ${{ inputs.opItem }}/GITBOOK_API_URL
+              GITBOOK_API_PUBLIC_URL: ${{ inputs.opItem }}/GITBOOK_API_PUBLIC_URL
+              GITBOOK_API_TOKEN: ${{ inputs.opItem }}/GITBOOK_API_TOKEN
+              GITBOOK_OAUTH_SERVER_URL: ${{ inputs.opItem }}/GITBOOK_OAUTH_SERVER_URL
+              GITBOOK_SITE_OAUTH_SIGNING_SECRET: ${{ inputs.opItem }}/GITBOOK_SITE_OAUTH_SIGNING_SECRET
+              GITBOOK_PREVIEW_BASE_URL: ${{ inputs.opItem }}/GITBOOK_PREVIEW_BASE_URL
+              GITBOOK_INTEGRATIONS_HOST: ${{ inputs.opItem }}/GITBOOK_INTEGRATIONS_HOST
+              GITBOOK_INTEGRATIONS_CONTENT_HOST: ${{ inputs.opItem }}/GITBOOK_INTEGRATIONS_CONTENT_HOST
+              GITBOOK_IMAGE_RESIZE_SIGNING_KEY: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_SIGNING_KEY
+              GITBOOK_IMAGE_RESIZE_URL: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_URL_2
+              GITBOOK_IMAGE_RESIZE_SALT: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_SALT
+              GITBOOK_IMAGE_RESIZE_MODE: ${{ inputs.opItem }}/GITBOOK_IMAGE_RESIZE_MODE
+              GITBOOK_ASSETS_PREFIX: ${{ inputs.opItem }}/GITBOOK_ASSETS_PREFIX
+              GITBOOK_FONTS_URL: ${{ inputs.opItem }}/GITBOOK_FONTS_URL
+        - name: Inject build env vars
+          if: ${{ inputs.environment == 'preview' }}
+          shell: bash
+          run: |
+              HEAD_SHA=$(git rev-parse HEAD)
+              echo "resolved HEAD_SHA: $HEAD_SHA"
+              echo "GITBOOK_HEAD_SHA=$HEAD_SHA" >> .vercel/.env.${{ inputs.environment }}.local
+              echo "GITBOOK_RUNTIME=vercel" >> .vercel/.env.${{ inputs.environment }}.local
+              echo "GITBOOK_BLOCK_SEARCH_INDEXATION=true" >> .vercel/.env.${{ inputs.environment }}.local
+              echo "GITBOOK_ALLOW_CUSTOMIZATION_OVERRIDE=true" >> .vercel/.env.${{ inputs.environment }}.local
+              echo "GITBOOK_DISABLE_INSIGHTS=true" >> .vercel/.env.${{ inputs.environment }}.local
+              echo "--- .vercel/.env.${{ inputs.environment }}.local after inject ---"
+              cat .vercel/.env.${{ inputs.environment }}.local
         - name: Build Project Artifacts
           run: bun run vercel build --target=${{ inputs.environment }} --token=${{ inputs.vercelToken }}
           shell: bash
           env:
-            VERCEL_ORG_ID: ${{ inputs.vercelOrg }}
-            VERCEL_PROJECT_ID: ${{ inputs.vercelProject }}
-            GITBOOK_RUNTIME: vercel
+              VERCEL_ORG_ID: ${{ inputs.vercelOrg }}
+              VERCEL_PROJECT_ID: ${{ inputs.vercelProject }}
+              GITBOOK_RUNTIME: vercel
+              GITBOOK_HEAD_SHA: ${{ inputs.headSha }}
         - name: Deploy Project Artifacts to Vercel
           id: deploy
           shell: bash
@@ -71,10 +93,9 @@ runs:
               DEPLOYMENT_URL=$(bun run vercel deploy --prebuilt --target=${{ inputs.environment }} --token=${{ inputs.vercelToken }})
               echo "deployment-url=$DEPLOYMENT_URL" >> "$GITHUB_OUTPUT"
           env:
-            VERCEL_ORG_ID: ${{ inputs.vercelOrg }}
-            VERCEL_PROJECT_ID: ${{ inputs.vercelProject }}
+              VERCEL_ORG_ID: ${{ inputs.vercelOrg }}
+              VERCEL_PROJECT_ID: ${{ inputs.vercelProject }}
         - name: Outputs
           shell: bash
           run: |
               echo "URL: ${{ steps.deploy.outputs.deployment-url }}"
-

.github/pull_request_template.md

@@ -0,0 +1,17 @@
+## Proposed changes
+
+<!-- Briefly describe what changed. Include relevant validation. -->
+
+## Demo
+
+<!-- Add screenshots or a recording when useful. Otherwise, remove this section. -->
+
+<!-- Optional: add Context here only when it explains a concrete problem and result that the changelog does not. Remove this comment before submitting. -->
+
+## Changelog
+
+<!-- Keep the relevant entries and remove unused placeholders. Feature = user-facing addition or improvement; Fix = user-facing bug fix; Chore = internal maintenance. -->
+
+- [Feature] ...
+- [Fix] ...
+- [Chore] ...

.github/slack-pr-status-app-manifest.json

@@ -0,0 +1,22 @@
+{
+    "display_information": {
+        "name": "PR Status",
+        "description": "Updates PR status reactions in engineering"
+    },
+    "features": {
+        "bot_user": {
+            "display_name": "PR Status",
+            "always_online": false
+        }
+    },
+    "oauth_config": {
+        "scopes": {
+            "bot": ["channels:history", "reactions:read", "reactions:write"]
+        }
+    },
+    "settings": {
+        "org_deploy_enabled": false,
+        "socket_mode_enabled": false,
+        "token_rotation_enabled": false
+    }
+}

.github/slack-pr-status.md

@@ -0,0 +1,15 @@
+# Slack PR status
+
+[GitbookIO/slack-pr-status](https://github.com/GitbookIO/slack-pr-status) adds review-status reactions to PR links posted in [#engineering](https://gitbook.slack.com/archives/C01NXGWJELS). It runs from `.github/workflows/slack-pr-status.yml` in `GitbookIO/gitbook`, `GitbookIO/gitbook-x` and `GitbookIO/integrations`. Emojis and statuses are configured in that workflow; see the action's README for the options.
+
+Owner: Peter White.
+
+| Configuration | Value |
+| --- | --- |
+| Slack app | **PR Status** (`A0C2AGLAD0T`), created from `.github/slack-pr-status-app-manifest.json` |
+| Bot token | Repository Actions secret `SLAPR_SLACK_BOT_TOKEN` |
+| GitHub token | The workflow's `GITHUB_TOKEN`, read-only |
+
+Posts that link PRs from more than one repository are skipped, because each workflow's token can only read its own repository. PRs from forks get no reactions, because their workflows don't receive secrets.
+
+To disable it in one repository, run `gh workflow disable slack-pr-status.yml --repo GitbookIO/<repository>`. To stop it everywhere, revoke the PR Status app's token.

.github/workflows/ci.yaml

@@ -20,6 +20,20 @@ jobs:
               env:
                   PUPPETEER_SKIP_DOWNLOAD: 1
             - run: bun format:check
+    lint:
+        runs-on: ubuntu-latest
+        name: Lint
+        timeout-minutes: 6
+        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
+            - run: bun lint
     test:
         runs-on: ubuntu-latest
         name: Test

.github/workflows/css-browser-compatibility.yaml

@@ -0,0 +1,34 @@
+name: CSS browser compatibility
+
+on:
+    pull_request_target:
+        types: [opened, reopened, synchronize]
+
+permissions:
+    contents: read
+    pull-requests: read
+
+concurrency:
+    group: css-browser-compatibility-${{ github.event.pull_request.number }}
+    cancel-in-progress: true
+
+jobs:
+    check:
+        name: Check newly added CSS declarations
+        runs-on: ubuntu-latest
+        timeout-minutes: 6
+        steps:
+            # pull_request_target checks out the trusted base branch by default. Never use the PR ref here.
+            - name: Checkout trusted checker
+              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: Check CSS browser compatibility
+              working-directory: packages/gitbook
+              run: bun run check:css-browser-compatibility
+              env:
+                  GITHUB_TOKEN: ${{ github.token }}

.github/workflows/deploy-preview.yaml

@@ -11,7 +11,7 @@ jobs:
         runs-on: ubuntu-latest
         if: ${{ github.event_name == 'pull_request_target' && github.event.pull_request.head.repo.fork }}
         environment:
-          name: preview-approval
+            name: preview-approval
         steps:
             - name: Approval gate
               run: echo "Preview deployment approved."
@@ -21,8 +21,8 @@ jobs:
         needs: approval
         if: ${{ always() && (needs.approval.result == 'success' || needs.approval.result == 'skipped') }}
         environment:
-          name: 2v-preview
-          url: ${{ steps.deploy.outputs.deployment-url }}
+            name: 2v-preview
+            url: ${{ steps.deploy.outputs.deployment-url }}
         outputs:
             deployment-url: ${{ steps.deploy.outputs.deployment-url }}
         steps:
@@ -40,14 +40,15 @@ jobs:
                   vercelToken: ${{ secrets.VERCEL_TOKEN }}
                   opItem: op://gitbook-open/2v-preview
                   opServiceAccount: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
+                  headSha: ${{ github.event.pull_request.head.sha || github.sha }}
     deploy-v2-cloudflare:
         name: Deploy v2 to Cloudflare Worker (preview)
         runs-on: ubuntu-latest
         needs: approval
         if: ${{ always() && (needs.approval.result == 'success' || needs.approval.result == 'skipped') }}
         environment:
-          name: 2c-preview
-          url: ${{ steps.deploy.outputs.deployment-url }}
+            name: 2c-preview
+            url: ${{ steps.deploy.outputs.deployment-url }}
         outputs:
             deployment-url: ${{ steps.deploy.outputs.deployment-url || steps.extract-worker-id.outputs.worker-url }}
         steps:
@@ -71,10 +72,10 @@ jobs:
               id: extract-worker-id
               if: ${{ !steps.deploy.outputs.deployment-url }}
               run: |
-                if [[ "${{ steps.deploy.outputs.command-output }}" =~ Worker\ Version\ ID:\ ([0-9a-f]{8})-([0-9a-f-]+) ]]; then
-                  WORKER_ID_FIRST_PART="${BASH_REMATCH[1]}"
-                  echo "worker-url=https://${WORKER_ID_FIRST_PART}-gitbook-open-v2-preview.gitbook.workers.dev/" >> $GITHUB_OUTPUT
-                fi
+                  if [[ "${{ steps.deploy.outputs.command-output }}" =~ Worker\ Version\ ID:\ ([0-9a-f]{8})-([0-9a-f-]+) ]]; then
+                    WORKER_ID_FIRST_PART="${BASH_REMATCH[1]}"
+                    echo "worker-url=https://${WORKER_ID_FIRST_PART}-gitbook-open-v2-preview.gitbook.workers.dev/" >> $GITHUB_OUTPUT
+                  fi
             - name: Outputs
               run: |
                   echo "URL: ${{ steps.deploy.outputs.deployment-url || steps.extract-worker-id.outputs.worker-url }}"
@@ -137,7 +138,7 @@ jobs:
                   BASE_URL: ${{ needs.deploy-v2-vercel.outputs.deployment-url }}
                   SITE_BASE_URL: ${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/
                   ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
-                  ARGOS_BUILD_NAME: 'v2-vercel'
+                  ARGOS_BUILD_NAME: v2-vercel
     visual-testing-v2-cloudflare:
         runs-on: ubuntu-latest
         name: Visual Testing v2 (Cloudflare)
@@ -161,13 +162,13 @@ jobs:
                   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: 'v2-cloudflare'
+                  ARGOS_BUILD_NAME: v2-cloudflare
     visual-testing-customers-v2:
         runs-on: ubuntu-latest
         name: Visual Testing Customers v2
         needs: deploy-v2-vercel
         if: ${{ always() && needs.deploy-v2-vercel.result == 'success' }}
-        timeout-minutes: 15
+        timeout-minutes: 30
         steps:
             - name: Checkout
               uses: actions/checkout@v4
@@ -185,13 +186,61 @@ jobs:
                   BASE_URL: ${{ needs.deploy-v2-vercel.outputs.deployment-url }}
                   SITE_BASE_URL: ${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/
                   ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
-                  ARGOS_BUILD_NAME: 'customers-v2'
+                  ARGOS_BUILD_NAME: customers-v2-vercel
+
+            # Style recalc depends on the client bundle, not the host, so this runs here only and
+            # not in the Cloudflare job. Kept out of `e2e-customers`, which is a visual suite.
+            - name: Run style invalidation tests
+              if: always()
+              working-directory: packages/gitbook
+              run: bun run e2e-style-perf
+              env:
+                  BASE_URL: ${{ needs.deploy-v2-vercel.outputs.deployment-url }}
+                  SITE_BASE_URL: ${{ needs.deploy-v2-vercel.outputs.deployment-url }}/url/
+
+            # Runs on failure too: a blown style budget is exactly when the numbers are worth seeing.
+            - name: Build style invalidation report
+              if: always() && github.event_name != 'push'
+              id: style-perf
+              working-directory: packages/gitbook
+              run: |
+                  rows=$(cat test-results/style-perf.md 2>/dev/null || true)
+                  if [ -z "$rows" ]; then exit 0; fi
+                  {
+                    echo 'body<<STYLE_PERF_EOF'
+                    echo '### Style invalidation on a large API reference'
+                    echo
+                    echo 'Elements restyled by opening one popup on [the Snyk API reference](https://docs.snyk.io/snyk-api/reference/apps). A share near or above 100% means the insertion restyles the whole document.'
+                    echo
+                    echo '| interaction | restyled | page | share | budget | |'
+                    echo '| --- | ---: | ---: | ---: | ---: | :-: |'
+                    echo "$rows"
+                    echo 'STYLE_PERF_EOF'
+                  } >> "$GITHUB_OUTPUT"
+
+            - name: Find style invalidation comment
+              if: always() && github.event_name != 'push' && steps.style-perf.outputs.body != ''
+              uses: peter-evans/find-comment@v3
+              id: fc-style-perf
+              with:
+                  issue-number: ${{ github.event.pull_request.number }}
+                  comment-author: 'github-actions[bot]'
+                  body-includes: 'Style invalidation on a large API reference'
+
+            - name: Create or update style invalidation comment
+              if: always() && github.event_name != 'push' && steps.style-perf.outputs.body != ''
+              uses: peter-evans/create-or-update-comment@v4
+              with:
+                  comment-id: ${{ steps.fc-style-perf.outputs.comment-id }}
+                  issue-number: ${{ github.event.pull_request.number }}
+                  body: ${{ steps.style-perf.outputs.body }}
+                  edit-mode: replace
     visual-testing-customers-v2-cloudflare:
         runs-on: ubuntu-latest
         name: Visual Testing Customers v2 (Cloudflare)
         needs: deploy-v2-cloudflare
         if: ${{ always() && needs.deploy-v2-cloudflare.result == 'success' }}
-        timeout-minutes: 15
+        timeout-minutes: 30
         steps:
             - name: Checkout
               uses: actions/checkout@v4
@@ -209,7 +258,7 @@ jobs:
                   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'
+                  ARGOS_BUILD_NAME: customers-v2-cloudflare
     browserless-testing-v2-vercel:
         runs-on: ubuntu-latest
         name: Browserless Testing v2 (Vercel)

.github/workflows/deploy-production.yaml

@@ -7,7 +7,7 @@ jobs:
     deploy-v2-vercel:
         name: Deploy v2 to Vercel (production)
         runs-on: ubuntu-latest
-        environment: 
+        environment:
             name: 2v-production
             url: ${{ steps.deploy.outputs.deployment-url }}
         outputs:
@@ -19,16 +19,16 @@ jobs:
               id: deploy
               uses: ./.github/composite/deploy-vercel
               with:
-                environment: production
-                vercelOrg: ${{ secrets.VERCEL_ORG_ID }}
-                vercelProject: ${{ secrets.VERCEL_PROJECT_ID }}
-                vercelToken: ${{ secrets.VERCEL_TOKEN }}
-                opItem: op://gitbook-open/2v-production
-                opServiceAccount: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
+                  environment: production
+                  vercelOrg: ${{ secrets.VERCEL_ORG_ID }}
+                  vercelProject: ${{ secrets.VERCEL_PROJECT_ID }}
+                  vercelToken: ${{ secrets.VERCEL_TOKEN }}
+                  opItem: op://gitbook-open/2v-production
+                  opServiceAccount: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
     deploy-v2-cloudflare:
         name: Deploy v2 to Cloudflare Worker (production)
         runs-on: ubuntu-latest
-        environment: 
+        environment:
             name: 2c-production
             url: ${{ steps.deploy.outputs.deployment-url }}
         outputs:
@@ -50,4 +50,4 @@ jobs:
                   commitMessage: ${{ github.sha }}
             - name: Outputs
               run: |
-                  echo "URL: ${{ steps.deploy.outputs.deployment-url }}"
+                  echo "URL: ${{ steps.deploy.outputs.deployment-url }}"

.github/workflows/deploy-staging.yaml

@@ -7,7 +7,7 @@ jobs:
     deploy-v2-vercel:
         name: Deploy v2 to Vercel (staging)
         runs-on: ubuntu-latest
-        environment: 
+        environment:
             name: 2v-staging
             url: ${{ steps.deploy.outputs.deployment-url }}
         outputs:
@@ -19,16 +19,16 @@ jobs:
               id: deploy
               uses: ./.github/composite/deploy-vercel
               with:
-                environment: staging
-                vercelOrg: ${{ secrets.VERCEL_ORG_ID }}
-                vercelProject: ${{ secrets.VERCEL_PROJECT_ID }}
-                vercelToken: ${{ secrets.VERCEL_TOKEN }}
-                opItem: op://gitbook-open/2v-staging
-                opServiceAccount: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
+                  environment: staging
+                  vercelOrg: ${{ secrets.VERCEL_ORG_ID }}
+                  vercelProject: ${{ secrets.VERCEL_PROJECT_ID }}
+                  vercelToken: ${{ secrets.VERCEL_TOKEN }}
+                  opItem: op://gitbook-open/2v-staging
+                  opServiceAccount: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
     deploy-v2-cloudflare:
         name: Deploy v2 to Cloudflare Worker (staging)
         runs-on: ubuntu-latest
-        environment: 
+        environment:
             name: 2c-staging
             url: ${{ steps.deploy.outputs.deployment-url }}
         outputs:
@@ -50,4 +50,4 @@ jobs:
                   commitMessage: ${{ github.sha }}
             - name: Outputs
               run: |
-                  echo "URL: ${{ steps.deploy.outputs.deployment-url }}"
+                  echo "URL: ${{ steps.deploy.outputs.deployment-url }}"

.github/workflows/publish.yaml

@@ -4,7 +4,7 @@ on:
     push:
         branches:
             - main
-    
+
 concurrency: ${{ github.workflow }}-${{ github.ref }}
 
 jobs:
@@ -15,6 +15,10 @@ jobs:
             id-token: write
             pull-requests: write
             contents: write
+        env:
+            # The repo is managed by Bun, but publishing uses npm for provenance.
+            # Keep Corepack from rejecting packageManager: bun@... when npm runs.
+            COREPACK_ENABLE_PROJECT_SPEC: 0
         steps:
             - name: Checkout Repo
               uses: actions/checkout@v3
@@ -26,9 +30,10 @@ jobs:
               with:
                   node-version: 22
                   registry-url: 'https://registry.npmjs.org'
-            # Ensure npm 11.5.1 or later is installed
             - name: Update npm
-              run: npm install -g npm@latest
+              run: |
+                  corepack enable npm
+                  corepack install -g npm@latest
             - name: Setup Bun
               uses: ./.github/composite/setup-bun
             - name: Install dependencies
@@ -45,4 +50,3 @@ jobs:
                   # Using a PAT instead of GITHUB_TOKEN because we need to run workflows when releases are created
                   # https://github.com/orgs/community/discussions/26875#discussioncomment-3253761
                   GITHUB_TOKEN: ${{ secrets.GH_PERSONAL_TOKEN }}
-

.github/workflows/slack-pr-status.yml

@@ -0,0 +1,33 @@
+name: Slack PR status
+
+on:
+    pull_request_review:
+        types: [submitted, dismissed]
+    pull_request:
+        types: [closed, reopened]
+
+permissions:
+    contents: read
+    pull-requests: read
+
+jobs:
+    slack-pr-status:
+        # Secrets aren't available to workflows triggered from forks.
+        if: github.event.pull_request.head.repo.full_name == github.repository
+        runs-on: ubuntu-latest
+        steps:
+            - uses: GitbookIO/slack-pr-status@main
+              with:
+                  slack-token: ${{ secrets.SLAPR_SLACK_BOT_TOKEN }}
+                  config: |
+                      channels: [C01NXGWJELS]
+                      approvalsRequired: 1
+                      multiPr: aggregate
+                      emojis:
+                          commented: false
+                          partiallyApproved: next_track_button
+                          approved: pr-approved
+                          changesRequested: construction
+                          merged: merged
+                          closed: no_entry_sign
+                          partiallyReviewed: hourglass_flowing_sand

.gitignore

@@ -29,3 +29,6 @@ yarn-error.log*
 
 # Bun pack artifacts
 packages/*/*.tgz
+
+# Playwright MCP artifacts
+.playwright-mcp/

.oxfmtrc.json

@@ -0,0 +1,70 @@
+{
+    "$schema": "./node_modules/oxfmt/configuration_schema.json",
+    "printWidth": 100,
+    "tabWidth": 4,
+    "useTabs": false,
+    "semi": true,
+    "singleQuote": true,
+    "jsxSingleQuote": false,
+    "quoteProps": "as-needed",
+    "trailingComma": "es5",
+    "bracketSpacing": true,
+    "bracketSameLine": false,
+    "arrowParens": "always",
+    "endOfLine": "lf",
+    "sortImports": {
+        "customGroups": [
+            {
+                "groupName": "workspace",
+                "elementNamePattern": ["@gitbook/**"]
+            }
+        ],
+        "groups": [
+            ["value-builtin", "value-external", "type-builtin", "type-external"],
+            { "newlinesBetween": true },
+            "workspace",
+            { "newlinesBetween": true },
+            [
+                "value-internal",
+                "type-internal",
+                "value-parent",
+                "type-parent",
+                "value-sibling",
+                "type-sibling",
+                "value-index",
+                "type-index"
+            ],
+            "type-import",
+            "unknown"
+        ]
+    },
+    "sortPackageJson": false,
+    "sortTailwindcss": {
+        "config": "./packages/gitbook/tailwind.config.ts",
+        "attributes": ["class", "className", "style"],
+        "functions": ["clsx", "tw"]
+    },
+    "ignorePatterns": [
+        "**/node_modules/**",
+        "**/dist/**",
+        "**/build/**",
+        "**/public/**",
+        "**/.next/**",
+        "**/.open-next/**",
+        "**/.turbo/**",
+        "**/.vercel/**",
+        "**/.cache/**",
+        "**/.wrangler/**",
+        "**/*.log",
+        "**/*.MD",
+        "**/*.md",
+        "**/*.mdx",
+        "**/*.html",
+        "**/*.css",
+        "packages/embed/standalone/**",
+        "packages/openapi-parser/src/fixtures/**",
+        "packages/emoji-codepoints/index.ts",
+        "packages/icons/src/data/*.json",
+        "packages/gitbook/worker-configuration.d.ts"
+    ]
+}

.oxlintrc.json

@@ -0,0 +1,87 @@
+{
+    "$schema": "./node_modules/oxlint/configuration_schema.json",
+    "categories": {
+        "correctness": "warn",
+        "suspicious": "warn",
+        "perf": "warn"
+    },
+    "plugins": ["eslint", "typescript", "unicorn", "oxc", "react", "jsx-a11y", "vitest"],
+    "env": {
+        "builtin": true,
+        "browser": true,
+        "node": true,
+        "shared-node-browser": true,
+        "worker": true
+    },
+    "globals": {
+        "Bun": "readonly",
+        "GitBookIntegrationEvent": "readonly",
+        "React": "readonly"
+    },
+    "rules": {
+        "eslint/no-console": [
+            "warn",
+            {
+                "allow": ["assert", "error", "warn"]
+            }
+        ],
+        "eslint/no-control-regex": "warn",
+        "eslint/no-prototype-builtins": "warn",
+        "eslint/no-cond-assign": "warn",
+        "eslint/no-undef": "error",
+        "eslint/no-unused-vars": [
+            "error",
+            {
+                "argsIgnorePattern": "^_",
+                "caughtErrorsIgnorePattern": "^_",
+                "ignoreRestSiblings": true,
+                "varsIgnorePattern": "^_"
+            }
+        ],
+        "react/button-has-type": "warn",
+        "react/exhaustive-deps": "warn",
+        "react/jsx-key": "warn",
+        "react/jsx-no-useless-fragment": "warn",
+        "react/no-array-index-key": "warn",
+        "react/void-dom-elements-no-children": "warn",
+        "react/rules-of-hooks": "error",
+        "jsx-a11y/alt-text": "warn",
+        "jsx-a11y/anchor-is-valid": "warn",
+        "jsx-a11y/click-events-have-key-events": "warn",
+        "jsx-a11y/iframe-has-title": "warn",
+        "jsx-a11y/interactive-supports-focus": "warn",
+        "jsx-a11y/label-has-associated-control": "warn",
+        "jsx-a11y/no-noninteractive-tabindex": "warn",
+        "jsx-a11y/role-has-required-aria-props": "warn",
+        "jsx-a11y/tabindex-no-positive": "warn",
+        "typescript/array-type": "error",
+        "typescript/no-explicit-any": "warn",
+        "typescript/no-non-null-assertion": "warn",
+        "typescript/no-confusing-void-expression": "warn",
+        "typescript/only-throw-error": "error",
+        "vitest/no-focused-tests": "error",
+        "no-delete-var": "warn",
+        "no-debugger": "error",
+        "no-throw-literal": "error",
+        "use-isnan": "error",
+        "valid-typeof": "error"
+    },
+    "ignorePatterns": [
+        "**/node_modules/**",
+        "**/dist/**",
+        "**/build/**",
+        "**/public/**",
+        "**/.next/**",
+        "**/.open-next/**",
+        "**/.turbo/**",
+        "**/.vercel/**",
+        "**/.cache/**",
+        "**/.wrangler/**",
+        "packages/embed/standalone/**",
+        "packages/openapi-parser/src/fixtures/**",
+        "packages/emoji-codepoints/index.ts",
+        "packages/icons/src/data/*.json",
+        "packages/gitbook/worker-configuration.d.ts",
+        "**/*.css"
+    ]
+}

.vscode/extensions.json

@@ -1,3 +1,3 @@
 {
-    "recommendations": ["biomejs.biome"]
+    "recommendations": ["oxc.oxc-vscode"]
 }

.vscode/settings.json

@@ -8,14 +8,12 @@
         ["style \\=([^;]*);", "\\`([^\\`]*)\\`"]
     ],
     "tailwindCSS.classAttributes": ["class", "className", "style", ".*Style"],
-    "prettier.enable": false,
     "editor.formatOnSave": true,
-    "editor.defaultFormatter": "biomejs.biome",
+    "editor.defaultFormatter": "oxc.oxc-vscode",
     "editor.codeActionsOnSave": {
-        "source.organizeImports.biome": "explicit",
-        "source.fixAll.biome": "explicit"
+        "source.fixAll.oxc": "always"
     },
     "[typescript]": {
-        "editor.defaultFormatter": "biomejs.biome"
+        "editor.defaultFormatter": "oxc.oxc-vscode"
     }
 }

AGENTS.md

@@ -0,0 +1,82 @@
+# AGENTS Instructions
+
+## Commands
+
+```bash
+bun install          # Install dependencies
+bun dev              # Start dev server (all packages)
+bun run build        # Build all packages
+bun run lint         # Lint with Oxlint
+bun run format       # Format with Oxfmt (run after every change)
+bun run typecheck    # Type-check all packages
+bun run unit         # Run unit tests
+```
+
+## Development
+
+The dev server proxies published GitBook sites locally. After `bun dev`, access any published site at:
+
+```
+http://localhost:3000/url/<published-gitbook-url>
+```
+
+Examples:
+- `http://localhost:3000/url/gitbook.com/docs`
+- `http://localhost:3000/url/open-source.gitbook.io/midjourney`
+
+## Architecture
+
+```
+packages/
+  gitbook/          # Main Next.js app
+    src/
+      app/          # Next.js App Router (sites/)
+      components/   # React components
+      lib/          # Server utilities, data fetching
+      intl/         # Internationalization (translations/)
+  openapi-parser/   # OpenAPI 3.0/3.1/Swagger parser
+  react-openapi/    # OpenAPI rendering components
+  react-contentkit/ # ContentKit component rendering
+  embed/            # Embeddable GitBook components
+  shared/           # Shared utilities
+  icons/            # Icon assets
+  fonts/            # Font assets
+  colors/           # Color tokens
+  expr/             # GitBook expression evaluator
+  cache-do/         # Cloudflare DO cache
+  cache-tags/       # Cache tag utilities
+```
+
+## Testing
+
+```bash
+bun run unit         # Unit tests via bun test (not vitest)
+bun run e2e          # Playwright e2e tests (requires built app)
+```
+
+Run a specific test file:
+```bash
+cd packages/gitbook && bun test src/lib/cache.test.ts
+```
+
+## Changesets
+
+After committing code changes, create a changeset for the affected package:
+
+```md
+---
+"gitbook": patch
+---
+
+Provide a short description of the change.
+```
+
+Save as `.changeset/<name>.md`, then commit it separately with message: `changeset`
+
+## Formatting
+
+Linting uses Oxlint and formatting uses Oxfmt. Always run `bun run format` before committing.
+
+## Comments
+
+Comment to explain *why*, not *what* — the code already shows what it does. Keep comments short, ideally a single line. Avoid multi-line block comments that narrate mechanics a reader can follow from the code; they add noise and go stale. Reserve longer comments for genuinely non-obvious rationale: a subtle invariant, or a workaround and the reason it exists.

CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md

README.md

@@ -1,3 +1,7 @@
+<p align="center">
+  <img src="./assets/gitbook_icon_dark.svg" alt="GitBook" width="48" />
+</p>
+
 <h1 align="center">GitBook</h1>
 
 <p align="center">
@@ -81,7 +85,7 @@ GitBook Open uses fontawesome. For self-hosting and local development, for licen
 
 ## Contributing
 
-GitBook's rendering engine is fully open source and built on top of [Next.js](https://nextjs.org/). Head to our [contributing guide](https://github.com/GitbookIO/gitbook/blob/main/.github/CONTRIBUTING.md) to learn more about the workflow on adding your first Pull Request.
+GitBook's rendering engine is fully open source and built on top of [Next.js](https://nextjs.org/). Head to our [contributing guide](https://github.com/GitbookIO/gitbook/blob/main/.github/CONTRIBUTING.md) to learn how to report bugs and suggest changes.
 
 ### Types of contributions
 
@@ -89,22 +93,22 @@ We encourage you to contribute to GitBook to help us build the best tool for doc
 
 #### Translations
 
-The GitBook UI is rendered using a set of translation files found in [`packages/gitbook/src/intl/translations`](/packages/gitbook/src/intl/translations/). We welcome all additional translations for the UI.
+The GitBook UI is rendered using a set of translation files found in [`packages/gitbook/src/intl/translations`](/packages/gitbook/src/intl/translations/). Spotted a wrong or missing translation? Open an issue and let us know.
 
 #### Bugs
 
-Encounter a bug or find an issue you'd like to fix? Helping us fix issues related to GitBook greatly improves the experience for everyone. Head to the issues section of this repository to learn more about the types of bugs you can already help out with.
+Encounter a bug? [Open an issue](https://github.com/GitbookIO/gitbook/issues/new/choose) with as much detail as you can. Clear reports help us fix things faster for everyone.
 
 ## Deployment
 
 > [!WARNING]  
 > While it is possible to self-host this project, we do not recommend this unless you are certain this option fits your need.
 >
-> _Looking to add a specific feature in GitBook? Head to our [contributing guide](https://github.com/GitbookIO/gitbook/blob/main/.github/CONTRIBUTING.md) to get started._
+> _Looking for a specific feature in GitBook? Head to our [contributing guide](https://github.com/GitbookIO/gitbook/blob/main/.github/CONTRIBUTING.md) to suggest it._
 >
 > Self-hosting this project puts the responsibility of maintaining and merging future updates on **you**. We cannot guarantee support, maintenance, or updates to forked and self-hosted instances of this project.
 >
-> We want to make it as easy as possible for our community to collaborate and push the future of GitBook, which is why we encourage you to contribute to our product directly instead of creating your own version.
+> We want to make it as easy as possible for our community to collaborate and push the future of GitBook, which is why we encourage you to share your ideas with us instead of creating your own version.
 
 This project allows you to self-host the rendering portion of your GitBook published content. Self-hosting has pros and cons.
 

assets/gitbook_icon_dark.svg

@@ -0,0 +1,3 @@
+<svg width="65" height="65" viewBox="0 0 65 65" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M27.3963 34.2195C30.5255 36.0255 32.09 36.9285 33.8082 36.93C35.5265 36.9315 37.0926 36.0313 40.2249 34.2308L60.1913 22.7534C61.0927 22.2353 61.6484 21.2749 61.6484 20.2352C61.6484 19.1955 61.0927 18.2351 60.1913 17.717L40.2177 6.23554C37.0888 4.43695 35.5243 3.53766 33.8078 3.53833C32.0912 3.539 30.5275 4.43951 27.4 6.24053L10.2292 16.1286C10.102 16.2019 10.0383 16.2385 9.97905 16.2732C4.11368 19.7068 0.489862 25.9754 0.441408 32.7717C0.440918 32.8404 0.440918 32.9138 0.440918 33.0607C0.440918 33.2074 0.440918 33.2807 0.441407 33.3494C0.489754 40.138 4.10549 46.4008 9.96041 49.837C10.0196 49.8718 10.0831 49.9085 10.2101 49.9818L20.9658 56.1918C27.2331 59.8104 30.3668 61.6197 33.808 61.6208C37.2493 61.622 40.3842 59.8148 46.6539 56.2005L58.008 49.6551C61.1474 47.8454 62.7171 46.9405 63.579 45.4487C64.4409 43.957 64.4409 42.1451 64.4409 38.5215V31.5212C64.4409 30.5159 63.8965 29.5895 63.0182 29.1004C62.1683 28.627 61.1325 28.6341 60.2891 29.1189L37.0074 42.5019C35.4453 43.3998 34.6643 43.8487 33.8072 43.849C32.9501 43.8493 32.1688 43.4008 30.6062 42.5038L14.8487 33.4586C14.0593 33.0055 13.6647 32.7789 13.3477 32.738C12.625 32.6448 11.9301 33.0497 11.6548 33.7244C11.534 34.0203 11.5365 34.4753 11.5414 35.3855C11.545 36.0555 11.5468 36.3905 11.6094 36.6987C11.7496 37.3887 12.1127 38.0136 12.6428 38.4771C12.8795 38.6842 13.1696 38.8516 13.7499 39.1866L30.5974 48.9103C32.164 49.8145 32.9473 50.2666 33.8075 50.2668C34.6677 50.267 35.4512 49.8154 37.0184 48.912L57.6684 37.0085C58.2037 36.7 58.4713 36.5457 58.672 36.6616C58.8727 36.7776 58.8727 37.0865 58.8727 37.7044V40.8796C58.8727 41.7855 58.8727 42.2385 58.6572 42.6114C58.4417 42.9844 58.0493 43.2106 57.2644 43.663L40.2322 53.4811C37.0966 55.2885 35.5288 56.1923 33.8078 56.1915C32.0869 56.1907 30.5199 55.2855 27.386 53.4752L11.4509 44.2701C11.4003 44.2409 11.375 44.2262 11.3514 44.2125C8.0102 42.26 5.94856 38.6882 5.92922 34.8185C5.92909 34.7911 5.92909 34.7619 5.92909 34.7035V31.7889C5.92909 29.6526 7.06686 27.678 8.9151 26.6067C10.5483 25.66 12.5628 25.6582 14.1977 26.6018L27.3963 34.2195Z" fill="#181C1F"/>
+</svg>

biome.json

@@ -1,177 +0,0 @@
-{
-    "$schema": "https://biomejs.dev/schemas/1.9.4/schema.json",
-    "vcs": {
-        "enabled": false,
-        "clientKind": "git",
-        "useIgnoreFile": false
-    },
-    "files": {
-        "ignoreUnknown": false,
-        "ignore": [
-            "**/node_modules/**/*",
-            "**/dist/**/*",
-            "**/build/**/*",
-            "**/public/**/*",
-            "**/.next/**/*",
-            "**/.open-next/**/*",
-            "**/.turbo/**/*",
-            "**/.vercel/**/*",
-            "**/.cache/**/*",
-            "**/.wrangler/**/*",
-            "packages/embed/standalone/**/*",
-            "packages/openapi-parser/src/fixtures/**/*",
-            "packages/emoji-codepoints/index.ts",
-            "packages/icons/src/data/*.json",
-            "packages/gitbook/worker-configuration.d.ts",
-            "**/*.css"
-        ]
-    },
-    "formatter": {
-        "enabled": true,
-        "useEditorconfig": true,
-        "formatWithErrors": false,
-        "indentStyle": "space",
-        "indentWidth": 4,
-        "lineEnding": "lf",
-        "lineWidth": 100,
-        "attributePosition": "auto",
-        "bracketSpacing": true
-    },
-    "organizeImports": {
-        "enabled": true
-    },
-    "linter": {
-        "enabled": true,
-        "rules": {
-            "recommended": true,
-            "performance": {
-                "noDelete": "warn"
-            },
-            "security": {
-                "noDangerouslySetInnerHtml": "off"
-            },
-            "complexity": {
-                "noForEach": "off",
-                "noUselessFragments": "warn",
-                "noBannedTypes": "warn"
-            },
-            "correctness": {
-                "noUndeclaredVariables": "error",
-                "noUnusedVariables": "error",
-                "useArrayLiterals": "error",
-                "useHookAtTopLevel": "error",
-                "noUnusedImports": "error",
-                "noVoidElementsWithChildren": "warn",
-                "useJsxKeyInIterable": "warn",
-                "useExhaustiveDependencies": "warn",
-                "noUnknownFunction": "warn"
-            },
-            "style": {
-                "noNonNullAssertion": "warn",
-                "noParameterAssign": "off",
-                "useThrowOnlyError": "error"
-            },
-            "suspicious": {
-                "noConsole": {
-                    "level": "warn",
-                    "options": {
-                        "allow": ["assert", "error", "warn"]
-                    }
-                },
-                "noExplicitAny": "warn",
-                "noImplicitAnyLet": "warn",
-                "noConfusingVoidType": "warn",
-                "noControlCharactersInRegex": "warn",
-                "noPrototypeBuiltins": "warn",
-                "noAssignInExpressions": "warn",
-                "noArrayIndexKey": "warn"
-            },
-            "a11y": {
-                "useSemanticElements": "warn",
-                "useKeyWithClickEvents": "warn",
-                "noSvgWithoutTitle": "warn",
-                "useButtonType": "warn",
-                "useIframeTitle": "warn",
-                "useAltText": "warn",
-                "noPositiveTabindex": "warn",
-                "useFocusableInteractive": "warn",
-                "useAriaPropsForRole": "warn",
-                "useValidAnchor": "warn",
-                "noLabelWithoutControl": "warn",
-                "noNoninteractiveTabindex": "warn"
-            },
-            "nursery": {
-                "useSortedClasses": {
-                    "level": "error",
-                    "fix": "safe",
-                    "options": {
-                        "attributes": ["class", "className", "style"],
-                        "functions": ["clsx", "tw"]
-                    }
-                }
-            }
-        }
-    },
-    "javascript": {
-        "formatter": {
-            "jsxQuoteStyle": "double",
-            "quoteProperties": "asNeeded",
-            "trailingCommas": "es5",
-            "semicolons": "always",
-            "arrowParentheses": "always",
-            "bracketSameLine": false,
-            "quoteStyle": "single",
-            "attributePosition": "auto",
-            "bracketSpacing": true
-        }
-    },
-    "overrides": [
-        {
-            "include": [
-                "packages/gitbook/**/*",
-                "packages/react-openapi/**/*",
-                "packages/react-math/**/*",
-                "packages/react-contentkit/**/*",
-                "packages/icons/**/*"
-            ],
-            "javascript": {
-                "globals": ["React"]
-            }
-        },
-        {
-            "include": ["packages/gitbook/**/*"],
-            "javascript": {
-                "globals": ["React", "GitBookIntegrationEvent"]
-            }
-        },
-        {
-            "include": ["*.css"],
-            "javascript": {
-                "globals": ["theme"]
-            }
-        },
-        {
-            "include": ["*.test.ts", "packages/gitbook/tests/**/*"],
-            "javascript": {
-                "globals": ["Bun"]
-            }
-        },
-        {
-            "include": [
-                "packages/cache-do/**/*",
-                "packages/gitbook/cf-env.d.ts",
-                "packages/gitbook/src/cloudflare-entrypoint.ts"
-            ],
-            "javascript": {
-                "globals": [
-                    "DurableObjectLocationHint",
-                    "DurableObjectNamespace",
-                    "DurableObjectStub",
-                    "ContinentCode",
-                    "Fetcher",
-                    "ExportedHandler"
-                ]
-            }
-        }
-    ]
-}

package.json

@@ -5,10 +5,11 @@
         "node": "^22.3.0"
     },
     "devDependencies": {
-        "@biomejs/biome": "^1.9.4",
-        "@changesets/cli": "^2.29.8",
-        "turbo": "^2.7.6",
-        "vercel": "^39.4.2"
+        "@changesets/cli": "^2.31.1",
+        "oxfmt": "^0.62.0",
+        "oxlint": "^1.90.0",
+        "turbo": "^2.11.10",
+        "vercel": "50.37.3"
     },
     "packageManager": "bun@1.3.7",
     "overrides": {
@@ -17,7 +18,8 @@
         "@types/react-dom": "catalog:",
         "react": "catalog:",
         "react-dom": "catalog:",
-        "esbuild": "0.24.2"
+        "esbuild": "0.27.3",
+        "axios": "1.8.4"
     },
     "private": true,
     "scripts": {
@@ -25,8 +27,10 @@
         "build": "turbo run build",
         "clean-deps": "rm -rf node_modules && rm -rf packages/*/node_modules",
         "typecheck": "turbo run typecheck",
-        "format": "biome check --write ./",
-        "format:check": "biome check --diagnostic-level=error ./",
+        "lint": "oxlint --quiet",
+        "lint:fix": "oxlint --fix --quiet",
+        "format": "oxfmt",
+        "format:check": "oxfmt --check",
         "unit": "turbo run unit",
         "e2e": "turbo run e2e",
         "e2e-customers": "turbo run e2e-customers",
@@ -37,11 +41,14 @@
         "clean": "turbo run clean"
     },
     "workspaces": {
-        "packages": ["packages/*"],
+        "packages": [
+            "packages/*"
+        ],
         "catalog": {
             "@tsconfig/strictest": "^2.0.6",
             "@tsconfig/node20": "^20.1.6",
-            "@gitbook/api": "0.159.0",
+            "@base-ui/react": "^1.7.0",
+            "@gitbook/api": "0.206.0",
             "@scalar/api-client-react": "^1.3.46",
             "@types/react": "^19.0.0",
             "@types/react-dom": "^19.0.0",
@@ -53,11 +60,14 @@
             "react-dom": "^19.0.1",
             "tsdown": "^0.15.6",
             "typescript": "^5.5.3",
-            "usehooks-ts": "^3.1.1"
+            "usehooks-ts": "^3.1.1",
+            "vercel": "^50.26.1"
         }
     },
     "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"
+        "@vercel/next@4.4.2": "patches/@vercel%2Fnext@4.4.2.patch",
+        "next@16.4.3": "patches/next@16.4.3.patch",
+        "mermaid@11.16.1": "patches/mermaid@11.16.1.patch"
     }
 }

packages/browser-types/CHANGELOG.md

@@ -1,5 +1,26 @@
 # @gitbook/browser-types
 
+## 0.1.6
+
+### Patch Changes
+
+- bf674a4: Add an optional `context` property (string, up to 512 characters) to the `confirmation` of custom AI tools, shown above the confirmation dialog to help the user understand what they are approving or rejecting. The `confirmation` can now also be a function that receives the AI-provided input and returns the confirmation, so the context can be derived dynamically from the arguments the tool is about to run with. Available both to integrations (`GitBookIntegrationTool`) and to embed consumers (`GitBookToolDefinition`).
+
+## 0.1.5
+
+### Patch Changes
+
+- 5f66860: Use isCookiesTrackingDisabled for cookie consent integrations
+- 2e495cb: Add Global Privacy Control (GPC) support
+
+## 0.1.4
+
+### Patch Changes
+
+- 7a11861: Add support for custom cookie banner registration
+- Updated dependencies [6f1db32]
+  - @gitbook/icons@0.4.3
+
 ## 0.1.3
 
 ### Patch Changes

packages/browser-types/package.json

@@ -9,7 +9,7 @@
         }
     },
     "sideEffects": false,
-    "version": "0.1.3",
+    "version": "0.1.6",
     "dependencies": {
         "@gitbook/api": "catalog:",
         "@gitbook/icons": "workspace:"
@@ -25,7 +25,11 @@
         "dev": "bun run build -- --watch ./src",
         "publish-to-npm": "../../scripts/publish-if-new.sh"
     },
-    "files": ["dist", "README.md", "CHANGELOG.md"],
+    "files": [
+        "dist",
+        "README.md",
+        "CHANGELOG.md"
+    ],
     "publishConfig": {
         "access": "public",
         "registry": "https://registry.npmjs.org/"

packages/browser-types/src/index.ts

@@ -5,14 +5,28 @@ export type GitBookIntegrationEvent = 'load' | 'unload';
 
 export type GitBookIntegrationEventCallback = (...args: any[]) => void;
 
+export type GitBookIntegrationToolConfirmation = {
+    icon?: IconName;
+    label: string;
+
+    /**
+     * Supporting context displayed to the user above the confirmation dialog,
+     * to help them understand what they are approving or rejecting.
+     * Limited to 512 characters.
+     */
+    context?: string;
+};
+
 export type GitBookIntegrationTool = AIToolDefinition & {
     /**
      * Confirmation action to be displayed to the user before executing the tool.
+     * Provide a static object, or a function that receives the input provided by
+     * the AI assistant and returns the confirmation — useful to display dynamic
+     * context based on the arguments the tool is about to be executed with.
      */
-    confirmation?: {
-        icon?: IconName;
-        label: string;
-    };
+    confirmation?:
+        | GitBookIntegrationToolConfirmation
+        | ((input: object) => GitBookIntegrationToolConfirmation);
 
     /**
      * Callback when the tool is executed.
@@ -85,10 +99,17 @@ export type GitBookGlobal = {
     registerCookieBanner: (handler: GitBookCookieBannerHandler) => void;
 
     /**
-     * Whether the user has granted cookie consent.
-     * Returns true if cookies are granted, false if rejected or unknown.
+     * Indicates whether cookies tracking is disabled for the current user.
+     * Returns `true` when tracking is disabled, `false` when tracking is enabled,
+     * and `undefined` when the tracking preference is unknown or not yet determined.
      */
-    hasApprovedCookies: () => boolean;
+    isCookiesTrackingDisabled: () => boolean | undefined;
+
+    /**
+     * Indicates whether global privacy control is enabled for the current user.
+     * Returns `true` when global privacy control is enabled, `false` when it is disabled.
+     */
+    isGlobalPrivacyControlEnabled: () => boolean;
 };
 
 declare global {

packages/cache-tags/package.json

@@ -24,7 +24,11 @@
         "dev": "bun run build -- --watch ./src",
         "publish-to-npm": "../../scripts/publish-if-new.sh"
     },
-    "files": ["dist", "README.md", "CHANGELOG.md"],
+    "files": [
+        "dist",
+        "README.md",
+        "CHANGELOG.md"
+    ],
     "publishConfig": {
         "access": "public",
         "registry": "https://registry.npmjs.org/"

packages/cache-tags/src/index.ts

@@ -1,14 +1,15 @@
-import type { ComputedContentSource } from '@gitbook/api';
 import assertNever from 'assert-never';
 
+import type { ComputedContentSource } from '@gitbook/api';
+
 /**
  * Get a stringified cache tag for a given object.
  */
 export function getCacheTag(
     spec: /**
-     * All data related to a user
-     * @deprecated - in v2, no tag as this is an immutable data
-     */
+         * All data related to a user
+         * @deprecated - in v2, no tag as this is an immutable data
+         */
         | {
               tag: 'user';
               user: string;

packages/colors/CHANGELOG.md

@@ -1,5 +1,11 @@
 # @gitbook/colors
 
+## 0.4.4
+
+### Patch Changes
+
+- a69a307: A near-white tint color (e.g. a warm `#F5F3EF`) is now taken as the exact page background, mirroring the existing behavior for near-black tints. The tint's exact lightness, hue and chroma are preserved, and the color is anchored to whichever scale step the active theme renders as the background — so it matches exactly on `muted` (which uses the second step) as well as `clean`. This applies only to near-neutral tints that are light enough to read as a background; saturated or merely light-ish colors keep their normal accent scale. The `bold` theme is unaffected: it already uses the tint for the header and stays intentionally two-tone.
+
 ## 0.4.3
 
 ### Patch Changes

packages/colors/package.json

@@ -8,7 +8,7 @@
         }
     },
     "sideEffects": false,
-    "version": "0.4.3",
+    "version": "0.4.4",
     "devDependencies": {
         "bun-types": "catalog:",
         "tsdown": "catalog:",
@@ -17,10 +17,15 @@
     "scripts": {
         "build": "tsdown",
         "typecheck": "tsc --noEmit",
+        "unit": "bun test",
         "dev": "bun run build -- --watch ./src",
         "publish-to-npm": "../../scripts/publish-if-new.sh"
     },
-    "files": ["dist", "README.md", "CHANGELOG.md"],
+    "files": [
+        "dist",
+        "README.md",
+        "CHANGELOG.md"
+    ],
     "publishConfig": {
         "access": "public",
         "registry": "https://registry.npmjs.org/"

packages/colors/src/transformations.test.ts

@@ -0,0 +1,69 @@
+import { describe, expect, it } from 'bun:test';
+
+import { colorScale } from './transformations';
+
+describe('colorScale exact base', () => {
+    it('takes a very light tint as the exact background on step 1 (clean/bold)', () => {
+        const scale = colorScale('#F5F3EF', { baseStep: 1 });
+        expect(scale[0]).toBe('#F5F3EF');
+    });
+
+    it('anchors a very light tint to step 2 when the theme uses the subtle step (muted)', () => {
+        const scale = colorScale('#F5F3EF', { baseStep: 2 });
+        expect(scale[1]).toBe('#F5F3EF');
+        // Step 1 sits just above the exact base, toward white.
+        expect(scale[0]).not.toBe('#F5F3EF');
+        expect(scale[0]).not.toBe('#ffffff');
+    });
+
+    it('takes a darker-than-dark tint as the exact background, preserving hue and chroma', () => {
+        const scale = colorScale('#0B0F19', { darkMode: true, baseStep: 1 });
+        expect(scale[0]).toBe('#0B0F19');
+    });
+
+    it('does not trigger for a normal mid-lightness tint', () => {
+        const scale = colorScale('#787878', { baseStep: 2 });
+        // The default white background is kept; the tint only colors the scale.
+        expect(scale[0]).toBe('#ffffff');
+        expect(scale[1]).not.toBe('#787878');
+    });
+
+    it('does not trigger for a saturated light color, keeping the normal accent ramp', () => {
+        // Light enough (L≈0.93) to pass the lightness bound, but too chromatic to read as a
+        // background — emitting it verbatim would leave a vivid step 1 above a near-gray scale.
+        const scale = colorScale('#FFEB3B', { baseStep: 1 });
+        expect(scale[0]).toBe('#ffffff');
+        expect(scale[0]).not.toBe('#FFEB3B');
+    });
+
+    it('respects a custom light background instead of overriding it with the tint', () => {
+        // The color is darker than the requested background, so it is not the extreme end and the
+        // supplied base must be preserved rather than overwritten.
+        const scale = colorScale('#eeeeee', { baseStep: 1, background: '#f8f8f8' });
+        expect(scale[0]).not.toBe('#eeeeee');
+    });
+
+    it('anchors an exact base even when a neutral mix is supplied (tint === primary)', () => {
+        // getTintMixColor blends neutral into the tint when it equals the primary color; that must
+        // not darken a near-white tint out of the exact-base path.
+        const scale = colorScale('#F5F3EF', {
+            baseStep: 1,
+            mix: { color: '#787878', ratio: 0.4 },
+        });
+        expect(scale[0]).toBe('#F5F3EF');
+    });
+
+    it('does not trigger for a light accent color below the near-white threshold', () => {
+        // #D8DEEC (light blue-gray, L≈0.90) is a UI accent, not a background, so it must not anchor.
+        const scale = colorScale('#D8DEEC', { baseStep: 1 });
+        expect(scale[0]).toBe('#ffffff');
+        expect(scale[0]).not.toBe('#D8DEEC');
+    });
+
+    it('never anchors when no baseStep is given (accent scales and the bold theme)', () => {
+        // A scale that does not define the page background opts out of the exact base entirely.
+        const scale = colorScale('#F5F3EF', {});
+        expect(scale[0]).toBe('#ffffff');
+        expect(scale[0]).not.toBe('#F5F3EF');
+    });
+});

packages/colors/src/transformations.ts

@@ -82,6 +82,22 @@ export const colorMixMapping = {
     dark: [0, 0.03, 0.08, 0.1, 0.13, 0.15, 0.2, 0.25, 0.5, 0.55, 0.75, 1],
 };
 
+/**
+ * Light mode has no equivalent to the dark base bound (nothing is lighter than white), so a tint
+ * at or above this lightness is treated as an explicit, near-white background (e.g. a warm `#F5F3EF`
+ * at L≈0.96). Kept high so light UI accent colors (around L≈0.90) aren't mistaken for backgrounds.
+ */
+const EXACT_BASE_LIGHT_THRESHOLD = 0.95;
+
+/**
+ * Only a near-neutral tint reads as a background. A saturated color would keep the exact hue at the
+ * anchored step while the rest of the low scale stays ~gray, so those keep the normal accent ramp.
+ */
+const EXACT_BASE_NEUTRAL_CHROMA = 0.05;
+
+/** Lightness of the default white light background (≈0.99999, not exactly 1). */
+const LIGHT_BASE_L = rgbToOklch(hexToRgbArray(LIGHT_BASE)).L;
+
 /**
  * Convert a hex color to an RGB color.
  */
@@ -159,6 +175,14 @@ export type ColorScaleOptions = {
     /** Define a custom foreground color to use. If left undefined, the global `light`/`dark` values (in `colors.ts`) will be used. */
     foreground?: string;
 
+    /**
+     * The 1-indexed scale step this scale renders as the page background (1 = `tint-base` for
+     * `clean`, 2 = `tint-subtle` for `muted`). When set, an extreme near-neutral tint is taken as
+     * the exact background, anchored to this step so it matches exactly. Omit for scales that don't
+     * define the page background (accents, or the two-tone `bold` theme) — they never anchor.
+     */
+    baseStep?: number;
+
     mix?: {
         /** If set to a hex code, this color will be additionally mixed into the generated scale according to `mix.ratio`. */
         color: string;
@@ -179,6 +203,7 @@ export function colorScale(
         darkMode = false,
         background = darkMode ? DARK_BASE : LIGHT_BASE,
         foreground = darkMode ? LIGHT_BASE : DARK_BASE,
+        baseStep,
         mix,
     }: ColorScaleOptions = {}
 ) {
@@ -188,31 +213,51 @@ export function colorScale(
     const backgroundColor = rgbToOklch(hexToRgbArray(background));
     let mapping = darkMode ? colorMixMapping.dark : colorMixMapping.light;
 
-    if (mixColor && mix?.ratio && mix.ratio > 0) {
-        // If defined, we mix in a (tiny) bit of the mix color with the base color.
+    // A near-neutral tint at the extreme end of the scale is taken as the exact page background
+    // rather than tinting pure black/white with it — letting brands set an exact background such as
+    // a warm `#F5F3EF`. Only scales that define the page background opt in (via `baseStep`). In light
+    // mode the base is pure white by default, so a near-white tint also qualifies (nothing is lighter
+    // than white); a custom, lower background is respected instead. Decided on the raw color so a
+    // neutral mix (below) can't darken a tint out of the exact base.
+    const isExtremeBase = darkMode
+        ? baseColor.L < backgroundColor.L
+        : backgroundColor.L >= LIGHT_BASE_L
+          ? baseColor.L > EXACT_BASE_LIGHT_THRESHOLD
+          : baseColor.L > backgroundColor.L;
+    const isExactBase =
+        baseStep !== undefined && isExtremeBase && baseColor.C < EXACT_BASE_NEUTRAL_CHROMA;
+    const exactBaseIndex = (baseStep ?? 1) - 1;
+
+    if (mixColor && mix?.ratio && mix.ratio > 0 && !isExactBase) {
+        // Mix a little of the mix color into the base — but not when the tint is the exact base,
+        // where it must stay true to the supplied color (and match `--header-background`).
         baseColor.L = mixColor.L * mix.ratio + baseColor.L * (1 - mix.ratio);
         baseColor.C = mixColor.C * mix.ratio + baseColor.C * (1 - mix.ratio);
         baseColor.H = mix.color === DEFAULT_TINT_COLOR ? baseColor.H : mixColor.H;
     }
 
-    if (
-        (darkMode && baseColor.L < backgroundColor.L) ||
-        (!darkMode && baseColor.L > backgroundColor.L)
-    ) {
-        // If the supplied color is outside of our lightness bounds, use the supplied color's lightness.
-        // This is mostly used to allow darker-than-dark backgrounds for brands that specifically want that look.
+    if (isExactBase) {
         const difference = (backgroundColor.L - baseColor.L) / backgroundColor.L;
-        backgroundColor.L = baseColor.L;
         // At the edges of the scale, the subtle lightness changes stop being perceptible. We need to amp up our mapping to still stand out.
         const amplifier = 1;
         mapping = mapping.map((step, index) =>
             index < 9 ? step + step * amplifier * difference : step
         );
+
+        // Anchor the supplied color to the step the theme renders as the background, solving the
+        // background lightness so neighbouring steps stay continuous with it.
+        const baseMix = mapping[exactBaseIndex]!;
+        backgroundColor.L = (baseColor.L - foregroundColor.L * baseMix) / (1 - baseMix);
     }
 
     const result = [];
 
     for (let index = 0; index < mapping.length; index++) {
+        if (isExactBase && index === exactBaseIndex) {
+            result.push(hex);
+            continue;
+        }
+
         const step = mapping[index]!;
         const targetL = foregroundColor.L * step + backgroundColor.L * (1 - step);
 
@@ -238,7 +283,10 @@ export function colorScale(
                 case 11:
                     return 0.1;
                 default:
-                    return index * 0.05;
+                    // When the tint is the exact base, hold the steps from the base toward the
+                    // accents at its chroma so the background stays tinted; steps lighter than the
+                    // base (e.g. cards in `muted`) keep desaturating toward white.
+                    return isExactBase && index >= exactBaseIndex ? 1 : index * 0.05;
             }
         })();
 

packages/embed/CHANGELOG.md

@@ -1,5 +1,61 @@
 # @gitbook/embed
 
+## 0.6.0
+
+### Minor Changes
+
+- f35be52: Add `defaultTab` and `defaultPage` options to the Docs Embed to choose where it opens. `defaultTab` opens the embed on the assistant, search or docs tab. `defaultPage` sets the page the docs tab opens on in place of the site's home page, and the embed opens on that page unless `defaultTab` says otherwise. Both work with the standalone script's `configure`, `frame.configure` and `<GitBookFrame>` props.
+
+### Patch Changes
+
+- 94a496c: Make the Docs Embed widget match the page it is embedded in rather than the visitor's OS: a widget on a light page stays light even when the visitor's system is in dark mode, and the widget's own chrome and the docs inside it always render in the same scheme. Sites published with a single theme impose it on the widget too, since they render in it regardless. The standalone script takes `?theme=light` on its URL, and calling `init` twice now updates the options instead of throwing.
+- bf674a4: Add an optional `context` property (string, up to 512 characters) to the `confirmation` of custom AI tools, shown above the confirmation dialog to help the user understand what they are approving or rejecting. The `confirmation` can now also be a function that receives the AI-provided input and returns the confirmation, so the context can be derived dynamically from the arguments the tool is about to run with. Available both to integrations (`GitBookIntegrationTool`) and to embed consumers (`GitBookToolDefinition`).
+
+## 0.5.1
+
+### Patch Changes
+
+- 37a9453: Allow copying in embed
+- Updated dependencies [47c8ccb]
+  - @gitbook/icons@0.5.0
+
+## 0.5.0
+
+### Minor Changes
+
+- 88c38fa: Add Search tab to Docs Embed, refactor search
+
+### Patch Changes
+
+- 8d2a95b: Docs Embed: Better support light/dark mode overrides
+
+## 0.4.0
+
+### Minor Changes
+
+- b3875a1: Support `assistantName` property to override Assistant name
+
+## 0.3.0
+
+### Minor Changes
+
+- 370b731: Docs Embed: Make trademark optional
+
+## 0.2.2
+
+### Patch Changes
+
+- b4b471f: Fix unexpected error thrown when using the embed in standalone mode
+
+## 0.2.1
+
+### Patch Changes
+
+- 96e24a1: Fix signed JWT token usage
+- 0aa34cc: Fix Embed options in React
+- Updated dependencies [6f1db32]
+  - @gitbook/icons@0.4.3
+
 ## 0.2.0
 
 ### Minor Changes

packages/embed/README.md

@@ -2,8 +2,9 @@
 
 Embed your GitBook docs in your product or website.
 
-The Docs Embed can contain two tabs:
+The Docs Embed can contain three tabs:
 - **Assistant**: The [GitBook Assistant](https://gitbook.com/docs/publishing-documentation/gitbook-ai-assistant) - an AI-powered chat interface to help users find answers
+- **Search**: A search-focused surface for quickly finding pages and asking scoped questions
 - **Docs**: A browser for navigating your documentation site
 
 The embed is set up automatically based on your site's configuration. You can optionally customize and override the configuration with custom actions, tools, suggested questions, [Authenticated Access](https://gitbook.com/docs/publishing-documentation/authenticated-access), and more. See the [Configuration](#configuration) section for all available options.
@@ -18,15 +19,27 @@ 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 `docs.company.com` with your docs site hostname.
 
+```html
+<script src="https://docs.company.com/~gitbook/embed/script.js"></script>
+```
+
+The script initializes the widget itself, so there is nothing to call. To pin the embed to one color
+scheme, put it on the script URL — it has to be known before the widget renders:
+
+```html
+<script src="https://docs.company.com/~gitbook/embed/script.js?theme=light"></script>
+```
+
+To authenticate the visitor, call `init` with their token. Keep tokens out of the script URL: it is
+publicly cacheable and ends up in server logs.
+
 ```html
 <script src="https://docs.company.com/~gitbook/embed/script.js"></script>
 <script>
-// Initialize with Authenticated Access (optional)
-window.GitBook('init', 
+window.GitBook('init',
     { siteURL: 'https://docs.company.com' },
     { visitor: { token: 'your-jwt-token' } }
 );
-window.GitBook('show');
 </script>
 ```
 
@@ -40,7 +53,8 @@ GitBook('configure', {
         label: 'Ask',
         icon: 'assistant' // 'assistant' | 'sparkle' | 'help' | 'book'
     },
-    tabs: ['assistant', 'docs'],
+    tabs: ['assistant', 'search', 'docs'],
+    defaultPage: '/getting-started',
     actions: [
         {
             icon: 'circle-question',
@@ -49,8 +63,10 @@ GitBook('configure', {
         }
     ],
     greeting: { title: 'Welcome!', subtitle: 'How can I help?' },
+    assistantName: 'Support Assistant',
     suggestions: ['What is GitBook?', 'How do I get started?'],
-    tools: [/* ... */]
+    tools: [/* ... */],
+    closeButton: true,
 });
 ```
 
@@ -70,6 +86,7 @@ const gitbook = createGitBook({
 // Create an iframe and get its URL
 const iframe = document.createElement('iframe');
 iframe.src = gitbook.getFrameURL({
+    colorScheme: 'dark', // Optional: force the embed to render in dark mode
     visitor: {
         token: 'your-jwt-token', // Optional: for Adaptive Content or Authenticated Access
         unsignedClaims: { // Optional: custom claims for dynamic expressions
@@ -90,7 +107,8 @@ frame.clearChat();
 
 // Configure the embed (see Configuration section for all options)
 frame.configure({
-    tabs: ['assistant', 'docs'],
+    tabs: ['assistant', 'search', 'docs'],
+    defaultPage: '/getting-started',
     actions: [
         {
             icon: 'circle-question',
@@ -99,8 +117,10 @@ frame.configure({
         }
     ],
     greeting: { title: 'Welcome!', subtitle: 'How can I help?' },
+    assistantName: 'Support Assistant',
     suggestions: ['What is GitBook?', 'How do I get started?'],
-    tools: [/* ... */]
+    tools: [/* ... */],
+    closeButton: true
 });
 
 // Listen to events
@@ -118,12 +138,15 @@ import { GitBookProvider, GitBookFrame } from '@gitbook/embed/react';
 
 <GitBookProvider siteURL="https://docs.company.com">
     <GitBookFrame
+        colorScheme="dark"
         visitor={{
             token: 'your-jwt-token', // Optional: for Adaptive Content or Authenticated Access
             unsignedClaims: { userId: '123' } // Optional: custom claims for dynamic expressions
         }}
-        tabs={['assistant', 'docs']}
+        tabs={['assistant', 'search', 'docs']}
+        defaultPage="/getting-started"
         greeting={{ title: 'Welcome!', subtitle: 'How can I help?' }}
+        assistantName="Support Assistant"
         suggestions={['What is GitBook?', 'How do I get started?']}
         actions={[
             {
@@ -133,6 +156,7 @@ import { GitBookProvider, GitBookFrame } from '@gitbook/embed/react';
             }
         ]}
         tools={[/* ... */]}
+        closeButton
     />
 </GitBookProvider>
 ```
@@ -144,7 +168,7 @@ import { useGitBook } from '@gitbook/embed/react';
 
 function MyComponent() {
     const gitbook = useGitBook();
-    const frameURL = gitbook.getFrameURL({ visitor: { token: '...' } });
+    const frameURL = gitbook.getFrameURL({ colorScheme: 'dark', visitor: { token: '...' } });
     // ...
 }
 ```
@@ -172,13 +196,13 @@ function MyComponent() {
 
 ### Standalone Script
 
-- `GitBook('init', options: { siteURL: string }, frameOptions?: { visitor?: {...} })` - Initialize widget
+- `GitBook('init', options: { siteURL: string }, frameOptions?: { colorScheme?: 'light' | 'dark', visitor?: {...} })` - Initialize widget
 - `GitBook('show')` - Show widget button
 - `GitBook('hide')` - Hide widget button
 - `GitBook('open')` - Open widget window
 - `GitBook('close')` - Close widget window
 - `GitBook('toggle')` - Toggle widget window
-- `GitBook('navigateToPage', path: string)` - Navigate to page
+- `GitBook('navigateToPage', path: string)` - Navigate to page (accepts the page path within the site, an absolute path, or the full published URL; resolves pages in any space/section)
 - `GitBook('navigateToAssistant')` - Navigate to assistant tab
 - `GitBook('postUserMessage', message: string)` - Post message to chat
 - `GitBook('clearChat')` - Clear chat history
@@ -189,11 +213,11 @@ function MyComponent() {
 
 **Client Factory:**
 - `createGitBook(options: { siteURL: string })` → `GitBookClient`
-- `client.getFrameURL(options?: { visitor?: {...} })` → `string`
+- `client.getFrameURL(options?: { colorScheme?: 'light' | 'dark', visitor?: {...} })` → `string`
 - `client.createFrame(iframe: HTMLIFrameElement)` → `GitBookFrameClient`
 
 **Frame Client:**
-- `frame.navigateToPage(path: string)` → `void`
+- `frame.navigateToPage(path: string)` → `void` (accepts the page path within the site, an absolute path, or the full published URL; resolves pages in any space/section)
 - `frame.navigateToAssistant()` → `void`
 - `frame.postUserMessage(message: string)` → `void`
 - `frame.clearChat()` → `void`
@@ -222,14 +246,88 @@ Available in: Standalone script, NPM package, React components
 
 Override which tabs are displayed. Defaults to your site's configuration.
 
-- **Type**: `('assistant' | 'docs')[]`
-- **Options**:
-  - `['assistant', 'docs']` - Show both tabs
-  - `['assistant']` - Show only the assistant tab
-  - `['docs']` - Show only the docs tab
+- **Type**: `('assistant' | 'search' | 'docs')[]`
 
 ```javascript
-tabs: ['assistant', 'docs']
+tabs: ['assistant', 'search', 'docs']
+```
+
+### `defaultTab`
+
+Available in: Standalone script, NPM package, React components
+
+The tab the embed opens on. Without it, the embed opens on `defaultPage` if set, otherwise on the assistant (or the docs when the assistant isn't available). The tab must be one of the enabled `tabs`.
+
+- **Type**: `'assistant' | 'search' | 'docs'`
+
+```javascript
+tabs: ['assistant', 'search', 'docs'],
+defaultTab: 'search'
+```
+
+`defaultTab` and `defaultPage` apply when the embed first loads: the standalone widget keeps its place when it is closed and reopened. To move it later, use `navigateToPage` or `navigateToAssistant`.
+
+### `defaultPage`
+
+Available in: Standalone script, NPM package, React components
+
+The page the docs tab opens on, in place of your site's home page. Accepts the same references as `navigateToPage`: the page's path within the site, an absolute path, or its full published URL. Unless `defaultTab` says otherwise, the embed opens on this page.
+
+- **Type**: `string`
+
+```javascript
+defaultPage: '/getting-started/quickstart'
+```
+
+### `closeButton`
+
+Available in: Standalone script, NPM package, React components
+
+Display a close (`x`) button in the embed sidebar.
+
+- **Type**: `boolean`
+- **Default**: `false`
+
+```javascript
+closeButton: true
+```
+
+Behavior:
+- When clicked, the embed sends a `close` event to the parent page.
+- In the standalone script, this event is handled automatically and the widget closes.
+- In custom iframe integrations (NPM package), you must listen for the `close` event and decide how to hide/collapse your UI.
+- In React, this works automatically when using the standard widget flow. If you build custom frame wiring, handle `close` the same way as the NPM package.
+
+NPM package example:
+
+```typescript
+const frame = gitbook.createFrame(iframe);
+
+frame.configure({
+    closeButton: true
+});
+
+const unsubscribe = frame.on('close', () => {
+    // Hide your modal/drawer/container
+    container.classList.add('hidden');
+});
+```
+
+Notes:
+- The close button is rendered in the same sidebar area as tabs/actions.
+- If your UI hides that sidebar or doesn't render it, the button will not be visible.
+
+### `trademark`
+
+Available in: Standalone script, NPM package, React components
+
+Display GitBook branding in the embed. Defaults to true.
+
+- **Type**: `boolean`
+- **Default**: `true`
+
+```javascript
+trademark: true
 ```
 
 ### `actions`
@@ -278,6 +376,18 @@ greeting: {
 }
 ```
 
+### `assistantName`
+
+Available in: Standalone script, NPM package, React components
+
+Override the assistant name displayed in the chat header and assistant entry points (for example, sidebar tabs and action labels). This name will be limited to 32 characters to prevent text overflow.
+
+- **Type**: `string`
+
+```javascript
+assistantName: 'Support Assistant'
+```
+
 ### `suggestions`
 
 Available in: Standalone script, NPM package, React components
@@ -392,6 +502,29 @@ visitor: {
 }
 ```
 
+### `colorScheme`
+
+Available in: Standalone script (via `init`), NPM package (via `getFrameURL()`), React components (as prop)
+
+Override the embed's color scheme.
+
+When omitted, the standalone widget follows the page it is embedded in — its `color-scheme`, falling back to the visitor's OS preference only when that page declares support for both. With the NPM package or the React components you own the iframe, so the embed follows the visitor's OS preference unless you pass this.
+
+**Note**: This is not a configuration option but rather a parameter when initializing the frame or creating the frame URL.
+
+**Standalone script**: `?theme=light` on the script URL
+**NPM package**: Pass to `getFrameURL({ colorScheme: 'dark' })`
+**React components**: Pass as the `colorScheme` prop on `<GitBookFrame>`
+
+- **Type**: `'light' | 'dark'`
+
+```html
+<script src="https://docs.company.com/~gitbook/embed/script.js?theme=light"></script>
+```
+
+Sites published with a single theme always render in that theme, so `colorScheme` has no effect on
+them — the widget follows the site instead, to keep its chrome and the docs inside it consistent.
+
 ### `button`
 
 Available in: Standalone script only

packages/embed/package.json

@@ -13,7 +13,7 @@
         }
     },
     "sideEffects": false,
-    "version": "0.2.0",
+    "version": "0.6.0",
     "dependencies": {
         "@gitbook/api": "catalog:",
         "@gitbook/icons": "workspace:",
@@ -39,7 +39,11 @@
         "dev": "bun run build -- --watch ./src",
         "publish-to-npm": "../../scripts/publish-if-new.sh"
     },
-    "files": ["dist", "README.md", "CHANGELOG.md"],
+    "files": [
+        "dist",
+        "README.md",
+        "CHANGELOG.md"
+    ],
     "publishConfig": {
         "access": "public",
         "registry": "https://registry.npmjs.org/"

packages/embed/src/client/createGitBook.test.ts

@@ -35,4 +35,17 @@ describe('createGitBook.getFrameURL', () => {
         expect(url.searchParams.get('visitor.count')).toBe('3');
         expect(url.searchParams.get('visitor.enabled')).toBe('false');
     });
+
+    it('adds an explicit color scheme override when requested', () => {
+        const client = createGitBook({ siteURL: 'https://example.com/docs/' });
+
+        const url = new URL(
+            client.getFrameURL({
+                colorScheme: 'dark',
+            })
+        );
+
+        expect(url.pathname).toBe('/docs/~gitbook/embed');
+        expect(url.searchParams.get('theme')).toBe('dark');
+    });
 });

packages/embed/src/client/createGitBook.ts

@@ -8,6 +8,14 @@ export type CreateGitBookOptions = {
 };
 
 export type GetFrameURLOptions = {
+    /**
+     * Override the color scheme used by the embedded docs.
+     * When omitted, the standalone widget follows the page it is embedded in, and only falls back
+     * to the visitor's OS preference when that page supports both schemes. Building the iframe
+     * yourself, the embed follows the visitor's OS preference unless you pass this.
+     */
+    colorScheme?: 'light' | 'dark';
+
     /**
      * Authentication to use for the frame.
      */
@@ -42,6 +50,10 @@ export function createGitBook(options: CreateGitBookOptions) {
             const url = new URL(options.siteURL);
             url.pathname = `${url.pathname.endsWith('/') ? url.pathname : `${url.pathname}/`}~gitbook/embed`;
 
+            if (frameOptions.colorScheme) {
+                url.searchParams.set('theme', frameOptions.colorScheme);
+            }
+
             if (frameOptions.visitor?.token) {
                 url.searchParams.set('jwt_token', frameOptions.visitor.token);
             }

packages/embed/src/client/createGitBookFrame.ts

@@ -1,4 +1,5 @@
 import { createChannel } from 'bidc';
+
 import type {
     FrameToParentMessage,
     GitBookEmbeddableConfiguration,
@@ -7,7 +8,12 @@ import type {
 
 export type GitBookFrameClient = {
     /**
-     * Navigate to a page by its path.
+     * Navigate to a page in the docs tab.
+     *
+     * Accepts the page's path within the site (e.g. `getting-started/quickstart`),
+     * an absolute path (e.g. `/help-center/integrations`), or its full published URL.
+     * The target page may live in any space/section of the site — including one other
+     * than the embed is currently showing — and is resolved to the right space.
      */
     navigateToPage: (path: string) => void;
 
@@ -44,6 +50,16 @@ export function createGitBookFrame(iframe: HTMLIFrameElement): GitBookFrameClien
     if (!iframe.contentWindow) {
         throw new Error('Iframe must have a content window');
     }
+
+    const allowTokens = iframe.allow
+        .split(';')
+        .map((token) => token.trim())
+        .filter(Boolean);
+
+    if (!allowTokens.includes('clipboard-write')) {
+        iframe.allow = [...allowTokens, 'clipboard-write'].join('; ');
+    }
+
     const channel = createChannel(iframe.contentWindow);
 
     channel.receive((message: FrameToParentMessage) => {
@@ -61,14 +77,15 @@ export function createGitBookFrame(iframe: HTMLIFrameElement): GitBookFrameClien
         channel.send(message);
     };
 
-    const events = new Map<string, Array<(...args: any[]) => void>>();
+    const events = new Map<string, ((...args: any[]) => void)[]>();
 
     const configuration: GitBookEmbeddableConfiguration = {
-        tabs: ['assistant', 'docs'],
+        tabs: ['assistant', 'search', 'docs'],
         actions: [],
         greeting: { title: '', subtitle: '' },
         suggestions: [],
         tools: [],
+        trademark: true,
     };
 
     return {

packages/embed/src/client/protocol.ts

@@ -1,17 +1,32 @@
 import type { AIToolCallResult, AIToolDefinition } from '@gitbook/api';
 import type { IconName } from '@gitbook/icons';
 
+/**
+ * Confirmation action to be displayed to the user before executing a tool.
+ */
+export type GitBookToolConfirmation = {
+    icon?: IconName;
+    label: string;
+
+    /**
+     * Supporting context displayed to the user above the confirmation dialog,
+     * to help them understand what they are approving or rejecting.
+     * Limited to 512 characters.
+     */
+    context?: string;
+};
+
 /**
  * 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.
+     * Provide a static object, or a function that receives the input provided by
+     * the AI assistant and returns the confirmation — useful to display dynamic
+     * context based on the arguments the tool is about to be executed with.
      */
-    confirmation?: {
-        icon?: IconName;
-        label: string;
-    };
+    confirmation?: GitBookToolConfirmation | ((input: object) => GitBookToolConfirmation);
 
     /**
      * Callback when the tool is executed.
@@ -45,7 +60,13 @@ export type GitBookEmbeddableActionDefinition = {
  */
 export type GitBookEmbeddableConfiguration = {
     /** Tabs to display in the embed (if enabled on the site). */
-    tabs: ('assistant' | 'docs')[];
+    tabs: ('assistant' | 'docs' | 'search')[];
+
+    /** Tab to open the embed on. */
+    defaultTab?: 'assistant' | 'docs' | 'search';
+
+    /** Page to open the docs tab on, instead of the site's home page. */
+    defaultPage?: string;
 
     /** Additional buttons to be displayed in the header of the GitBook embed. */
     actions: GitBookEmbeddableActionDefinition[];
@@ -62,11 +83,27 @@ export type GitBookEmbeddableConfiguration = {
         subtitle: string;
     };
 
+    /**
+     * Override the assistant name displayed in the UI.
+     * Limited to 32 characters.
+     */
+    assistantName?: string;
+
     /** Suggestions of questions to be displayed in the welcome page. */
     suggestions: string[];
 
     /** Tools to be provided to the assistant. */
     tools: GitBookToolDefinition[];
+
+    /**
+     * Display GitBook branding in the embed.
+     */
+    trademark?: boolean;
+
+    /**
+     * Display a close button inside the assistant.
+     */
+    closeButton?: boolean;
 };
 
 /**

packages/embed/src/react/GitBookFrame.tsx

@@ -1,6 +1,7 @@
 'use client';
 
 import { useEffect, useMemo, useRef, useState } from 'react';
+
 import type {
     GetFrameURLOptions,
     GitBookEmbeddableConfiguration,
@@ -19,19 +20,28 @@ export type GitBookFrameProps = {
 export function GitBookFrame(props: GitBookFrameProps) {
     const {
         className,
+        colorScheme,
         visitor,
         actions = [],
         greeting,
         suggestions = [],
         tools = [],
-        tabs = ['assistant', 'docs'],
+        tabs = ['assistant', 'search', 'docs'],
+        defaultTab,
+        defaultPage,
+        trademark = true,
+        closeButton = false,
+        assistantName,
     } = props;
 
     const frameRef = useRef<HTMLIFrameElement>(null);
     const gitbook = useGitBook();
     const [gitbookFrame, setGitbookFrame] = useState<GitBookFrameClient | null>(null);
 
-    const frameURL = useMemo(() => gitbook.getFrameURL({ visitor }), [gitbook, visitor]);
+    const frameURL = useMemo(
+        () => gitbook.getFrameURL({ visitor, colorScheme }),
+        [gitbook, visitor, colorScheme]
+    );
 
     useEffect(() => {
         if (frameRef.current) {
@@ -42,12 +52,29 @@ export function GitBookFrame(props: GitBookFrameProps) {
     useEffect(() => {
         gitbookFrame?.configure({
             tabs,
+            defaultTab,
+            defaultPage,
             actions,
             greeting,
             suggestions,
             tools,
+            closeButton,
+            trademark,
+            assistantName,
         });
-    }, [gitbookFrame, actions, greeting, suggestions, tools, tabs]);
+    }, [
+        gitbookFrame,
+        actions,
+        greeting,
+        suggestions,
+        tools,
+        tabs,
+        defaultTab,
+        defaultPage,
+        closeButton,
+        trademark,
+        assistantName,
+    ]);
 
     return (
         <iframe
@@ -56,6 +83,7 @@ export function GitBookFrame(props: GitBookFrameProps) {
             src={frameURL}
             width="100%"
             height="100%"
+            allow="clipboard-write"
             className={className}
         />
     );

packages/embed/src/react/GitBookProvider.tsx

@@ -1,6 +1,7 @@
 'use client';
 
 import * as React from 'react';
+
 import { type CreateGitBookOptions, createGitBook } from '../client';
 import { GitBookContext } from './context';
 

packages/embed/src/react/context.ts

@@ -1,6 +1,7 @@
 'use client';
 
 import * as React from 'react';
+
 import type { GitBookClient } from '../client';
 
 export const GitBookContext = React.createContext<GitBookClient | null>(null);

packages/embed/src/standalone/index.ts

@@ -55,6 +55,7 @@ let widgetIframe: HTMLIFrameElement | undefined;
 let _client: GitBookClient | undefined;
 let _frame: GitBookFrameClient | undefined;
 let frameOptions: GetFrameURLOptions | undefined;
+let frameConfigured = false;
 let frameConfiguration: GitBookEmbeddableConfiguration & StandaloneConfiguration = {
     button: {
         label: 'Ask',
@@ -64,7 +65,8 @@ let frameConfiguration: GitBookEmbeddableConfiguration & StandaloneConfiguration
     greeting: { title: '', subtitle: '' },
     suggestions: [],
     tools: [],
-    tabs: ['assistant', 'docs'],
+    tabs: ['assistant', 'search', 'docs'],
+    trademark: true,
 };
 
 const widgetButton = document.createElement('button');
@@ -84,6 +86,47 @@ widgetWindow.classList.add('hidden');
 document.body.appendChild(widgetButton);
 document.body.appendChild(widgetWindow);
 
+/**
+ * The one scheme everything follows: the widget's chrome, the frame's URL and the docs inside it.
+ * Either it was configured, or we match the page we are embedded in (RND-12558).
+ */
+function resolveColorScheme(): 'light' | 'dark' {
+    const configured = frameOptions?.colorScheme;
+    // Callers are plain JS, so anything else — a typo, a `system` — falls back to the page rather
+    // than reaching the CSS and the frame's URL, where the two would disagree.
+    return configured === 'light' || configured === 'dark' ? configured : hostColorScheme();
+}
+
+/**
+ * The scheme the embedding page renders in, which is not the visitor's OS preference: a page that
+ * never opted into dark stays light however the OS is set.
+ *
+ * Resolving a `light-dark()` is the only way to read it. A page's *used* color scheme isn't exposed
+ * anywhere — the CSSOM gives computed values, and a `<meta name="color-scheme">` (the common way to
+ * declare it) never even reaches those.
+ */
+function hostColorScheme(): 'light' | 'dark' {
+    const probe = document.createElement('div');
+    // The first `color` is the fallback where `light-dark()` is unsupported: without it the probe
+    // would inherit the page's own text colour and a white one would read as dark.
+    probe.style.cssText =
+        'display:none;color:rgb(0,0,0);color:light-dark(rgb(0,0,0), rgb(255,255,255))';
+    document.body.appendChild(probe);
+    const used = getComputedStyle(probe).color;
+    probe.remove();
+
+    return used === 'rgb(255, 255, 255)' ? 'dark' : 'light';
+}
+
+/** Mirror the resolved scheme onto the widget's own chrome, and hand it back for the frame's URL. */
+function applyColorScheme(): 'light' | 'dark' {
+    const colorScheme = resolveColorScheme();
+    for (const element of [widgetButton, widgetWindow]) {
+        element.dataset.colorScheme = colorScheme;
+    }
+    return colorScheme;
+}
+
 function getClient() {
     if (!_client) {
         throw new Error(
@@ -100,31 +143,63 @@ function getIframe() {
         widgetIframe?.remove();
         widgetIframe = document.createElement('iframe');
         widgetIframe.id = 'gitbook-widget-iframe';
-        widgetIframe.src = client.getFrameURL({
-            ...frameOptions,
-        });
+        widgetIframe.allow = 'clipboard-write';
+        // One read for both, so the docs can't come back in a different scheme than the panel.
+        widgetIframe.src = client.getFrameURL({ ...frameOptions, colorScheme: applyColorScheme() });
         widgetWindow.appendChild(widgetIframe);
 
         _frame = client.createFrame(widgetIframe);
+        _frame.on('close', () => {
+            widgetWindow.classList.add('hidden');
+            widgetButton.classList.remove('open');
+        });
+        // A new frame starts from the site's own defaults, so replay whatever the host configured.
+        if (frameConfigured) {
+            _frame.configure(frameConfiguration);
+        }
     }
     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.'
-                );
-            }
+        case 'init': {
+            // `~gitbook/embed/script.js` already calls `init`, so an integrator following the docs
+            // ends up calling it a second time. Take the new options instead of throwing: throwing
+            // here dropped every call queued behind it (RND-12558).
             _client = createGitBook(args[1]);
-            frameOptions = args[2];
+            frameOptions = {
+                // Replace rather than merge: a call that leaves out `visitor` — a logout, another
+                // site — must not keep the token from the last one.
+                ...args[2],
+                // Except the scheme, where the first one wins: `script.js` passes the site's own
+                // theme when it pins one, and that is not the integrator's to override.
+                colorScheme: frameOptions?.colorScheme ?? args[2]?.colorScheme,
+            };
+            const colorScheme = applyColorScheme();
+
+            // Rebuild the frame only if the new options change its URL — reloading it on the
+            // loader's `init` plus the integrator's would throw away a chat for nothing.
+            const frameURL = _client.getFrameURL({ ...frameOptions, colorScheme });
+            if (widgetIframe && widgetIframe.src !== frameURL) {
+                const wasOpen = !widgetWindow.classList.contains('hidden');
+                widgetIframe.remove();
+                widgetIframe = undefined;
+                _frame = undefined;
+                if (wasOpen) {
+                    getIframe();
+                }
+            }
             break;
+        }
         case 'unload':
             _client = undefined;
             _frame = undefined;
             widgetIframe?.remove();
+            widgetIframe = undefined;
+            frameOptions = undefined;
+            frameConfigured = false;
+            applyColorScheme();
             widgetWindow.classList.add('hidden');
             break;
         case 'show':
@@ -152,6 +227,19 @@ const GitBook = (...args: StandaloneCalls) => {
             break;
         case 'configure': {
             const settings = args[1];
+
+            // If trademark is disabled, change the (branded) icon to the sparkle icon
+            if (
+                settings.trademark === false &&
+                !settings.button?.icon &&
+                frameConfiguration.button.icon === 'assistant'
+            ) {
+                settings.button = {
+                    label: frameConfiguration.button.label,
+                    icon: 'sparkle',
+                };
+            }
+
             frameConfiguration = {
                 ...frameConfiguration,
                 ...settings,
@@ -170,6 +258,7 @@ const GitBook = (...args: StandaloneCalls) => {
                 }
             }
 
+            frameConfigured = true;
             getIframe().frame.configure({
                 ...frameConfiguration,
             });
@@ -192,6 +281,11 @@ 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', {});
+// Replay each queued call on its own, so one that throws doesn't drop the rest.
+precalls.forEach((call) => {
+    try {
+        GitBook(...call);
+    } catch (error) {
+        console.error('[gitbook:embed]', error);
+    }
+});

packages/embed/src/standalone/style.css

@@ -29,14 +29,30 @@
     --gitbook-widget-easing-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
 }
 
-@media (prefers-color-scheme: dark) {
-    :root {
-        --gitbook-widget-text-color: #FFFFFF;
-        --gitbook-widget-border-color: #202020;
-        --gitbook-widget-background-translucent: rgba(15, 15, 15, 0.9);
-        --gitbook-widget-background-translucent-hover: rgba(20, 20, 20, 0.9);
-        --gitbook-widget-background-solid: #f0f0f0;
-    }
+/* The widget owns the panel's surface, so it renders in the same scheme as the docs inside the
+ * iframe. `data-color-scheme` carries that one resolved scheme — see `resolveColorScheme()` — and
+ * is always set, so the declaration below only shows before the widget initializes (RND-12558).
+ * The colours are declared here rather than on `:root` because `light-dark()` resolves against the
+ * color-scheme of the element that declares them. The bundler lowers it to a variable toggle, so
+ * browsers without `light-dark()` still get both schemes. */
+#gitbook-widget-button,
+#gitbook-widget-window {
+    color-scheme: light;
+
+    --gitbook-widget-text-color: light-dark(#656973, #FFFFFF);
+    --gitbook-widget-border-color: light-dark(#e5e5e5, #202020);
+    --gitbook-widget-background-translucent: light-dark(rgba(255, 255, 255, 0.9), rgba(15, 15, 15, 0.9));
+    --gitbook-widget-background-translucent-hover: light-dark(rgba(250, 250, 250, 0.9), rgba(20, 20, 20, 0.9));
+    --gitbook-widget-background-solid: light-dark(#FFFFFF, #0f0f0f);
+    --gitbook-widget-background-solid-hover: light-dark(#FBFBFB, #141414);
+}
+#gitbook-widget-button[data-color-scheme="light"],
+#gitbook-widget-window[data-color-scheme="light"] {
+    color-scheme: light;
+}
+#gitbook-widget-button[data-color-scheme="dark"],
+#gitbook-widget-window[data-color-scheme="dark"] {
+    color-scheme: dark;
 }
 
 * {

packages/embed/turbo.json

@@ -0,0 +1,8 @@
+{
+    "extends": ["//"],
+    "tasks": {
+        "build": {
+            "outputs": ["dist/**", "standalone/**"]
+        }
+    }
+}

packages/emoji-codepoints/build.ts

@@ -1,6 +1,6 @@
+import emojisRaws from 'emoji-assets/emoji.json';
 import fs from 'node:fs';
 import path from 'node:path';
-import emojisRaws from 'emoji-assets/emoji.json';
 
 interface EmojiData {
     code_points: {

packages/expr/CHANGELOG.md

@@ -1,5 +1,29 @@
 # @gitbook/expr
 
+## 1.4.0
+
+### Minor Changes
+
+- 02f4cbc: Restrict expressions to an allowlist of methods and syntax, and report unsupported expressions when parsing.
+
+## 1.3.1
+
+### Patch Changes
+
+- 3fedaaa: Depend on `eval-estree-expression` from the npm registry (`^3.0.1`) instead of a pinned GitHub commit. The published `3.0.1` release is built from the exact commit the package was pinned to, so the code is unchanged — this only removes the fragile git/tarball dependency so consumers install it from npm like any other package.
+
+## 1.3.0
+
+### Minor Changes
+
+- 6eabaec: Implement a getVariables function for ExpressionRuntime
+
+## 1.2.5
+
+### Patch Changes
+
+- 8242f18: Extend gitbook/expr std lib with some additional methods
+
 ## 1.2.4
 
 ### Patch Changes

packages/expr/package.json

@@ -1,7 +1,7 @@
 {
     "name": "@gitbook/expr",
     "description": "Safely evaluate & parse user-defined GitBook expressions.",
-    "version": "1.2.4",
+    "version": "1.4.0",
     "type": "module",
     "exports": {
         ".": {
@@ -11,12 +11,12 @@
     },
     "sideEffects": false,
     "dependencies": {
-        "acorn": "^8.14.0",
-        "acorn-loose": "8.4.0",
+        "acorn": "^8.15.0",
+        "acorn-loose": "^8.5.2",
         "acorn-walk": "^8.3.4",
         "assert-never": "catalog:",
         "escodegen": "^2.1.0",
-        "eval-estree-expression": "github:jonschlinkert/eval-estree-expression#fb0246a"
+        "eval-estree-expression": "^4.0.0"
     },
     "devDependencies": {
         "@tsconfig/strictest": "catalog:",
@@ -36,7 +36,11 @@
         "dev": "bun run build -- --watch ./src",
         "publish-to-npm": "../../scripts/publish-if-new.sh"
     },
-    "files": ["dist", "README.md", "CHANGELOG.md"],
+    "files": [
+        "dist",
+        "README.md",
+        "CHANGELOG.md"
+    ],
     "publishConfig": {
         "access": "public",
         "registry": "https://registry.npmjs.org/"

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

@@ -25,6 +25,7 @@ describe('autocomplete', () => {
         description: 'An array of string',
         items: SymbolString(),
     });
+    const visitorClaimsKeyPropStringSymbol = SymbolString({ name: 'key' });
     const symbols = {
         visitor: SymbolObject({
             name: 'visitor',
@@ -33,7 +34,7 @@ describe('autocomplete', () => {
                     name: 'claims',
                     description: 'The claims contained in the visitor JWT token',
                     properties: {
-                        key: SymbolString({ name: 'key' }),
+                        key: visitorClaimsKeyPropStringSymbol,
                         flags: SymbolObject({
                             name: 'flags',
                             properties: {
@@ -57,10 +58,10 @@ describe('autocomplete', () => {
         }),
     };
     const context = new SymbolsTable(symbols);
-    const SCENARIOS: Array<{
+    const SCENARIOS: {
         expressionWithCursor: string;
         expectedSuggestions: AutocompleteSuggestions;
-    }> = [
+    }[] = [
         {
             expressionWithCursor: 'visit<cur>',
             expectedSuggestions: [
@@ -168,8 +169,12 @@ describe('autocomplete', () => {
                         childrenRefs: [
                             'visitor.claims.key.length',
                             'visitor.claims.key.at',
+                            'visitor.claims.key.startsWith',
                             'visitor.claims.key.endsWith',
                             'visitor.claims.key.includes',
+                            'visitor.claims.key.toLowerCase',
+                            'visitor.claims.key.toUpperCase',
+                            'visitor.claims.key.trim',
                         ],
                     },
                 },
@@ -227,8 +232,12 @@ describe('autocomplete', () => {
                         childrenRefs: [
                             'visitor.claims.role.length',
                             'visitor.claims.role.at',
+                            'visitor.claims.role.startsWith',
                             'visitor.claims.role.endsWith',
                             'visitor.claims.role.includes',
+                            'visitor.claims.role.toLowerCase',
+                            'visitor.claims.role.toUpperCase',
+                            'visitor.claims.role.trim',
                         ],
                     },
                 },
@@ -246,13 +255,47 @@ describe('autocomplete', () => {
                         childrenRefs: [
                             'visitor.claims.key.length',
                             'visitor.claims.key.at',
+                            'visitor.claims.key.startsWith',
                             'visitor.claims.key.endsWith',
                             'visitor.claims.key.includes',
+                            'visitor.claims.key.toLowerCase',
+                            'visitor.claims.key.toUpperCase',
+                            'visitor.claims.key.trim',
                         ],
                     },
                 },
             ],
         },
+        {
+            expressionWithCursor: 'visitor.claims.key.<cur>',
+            expectedSuggestions: [
+                {
+                    type: 'symbol',
+                    symbol: {
+                        definition: 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',
+                        }),
+                        ref: 'visitor.claims.key.length',
+                        parentRef: 'visitor.claims.key',
+                        childrenRefs: [],
+                    },
+                },
+                ...visitorClaimsKeyPropStringSymbol.methods.map<AutocompleteSymbolSuggestion>(
+                    (method) => ({
+                        type: 'symbol',
+                        symbol: {
+                            definition: method,
+                            ref: `visitor.claims.key.${method.name}`,
+                            parentRef: 'visitor.claims.key',
+                            childrenRefs: [],
+                        },
+                    })
+                ),
+            ],
+        },
         {
             expressionWithCursor: 'visitor.claims.h<cur>',
             expectedSuggestions: [

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

@@ -1,7 +1,15 @@
-import { describe, expect, it } from 'bun:test';
+import { parseExpressionAt } from 'acorn';
+import { afterEach, beforeEach, describe, expect, it, mock } from 'bun:test';
 
 import { ExpressionError } from '../errors';
+import {
+    ALLOWED_METHODS,
+    MAX_CALLBACK_CALLS,
+    UnsafeExpressionError,
+    evaluateRestricted,
+} from '../restricted';
 import { ExpressionRuntime } from '../runtime';
+import { SymbolArray, SymbolString } from '../symbols';
 import type { Logger } from '../types';
 
 const SILENT_LOGGER: Logger = {
@@ -10,6 +18,17 @@ const SILENT_LOGGER: Logger = {
     error: () => {},
 };
 
+const getInputs = () => ({ user: { role: 'editor' }, tags: ['b', 'a'], count: 1 });
+
+// Returns the thrown error instead of throwing, so that side effects can be asserted first.
+const attempt = (fn: () => unknown) => {
+    try {
+        return fn();
+    } catch (error) {
+        return error;
+    }
+};
+
 describe('ExpressionRuntime', () => {
     const runtime = new ExpressionRuntime(SILENT_LOGGER);
 
@@ -54,12 +73,172 @@ describe('ExpressionRuntime', () => {
                 inputs: { reviews: [{ status: 'approved' }, { status: 'approved' }] },
                 expectedResult: true,
             },
+            {
+                scenario: 'array includes',
+                condition: 'reviews.includes("approved")',
+                inputs: { reviews: ['pending', 'approved'] },
+                expectedResult: true,
+            },
             {
                 scenario: 'array map',
                 condition: '[1, 2, 3].map(n => n * x)',
                 inputs: { x: 2 },
                 expectedResult: [2, 4, 6],
             },
+            {
+                scenario: 'array filter',
+                condition: 'reviews.filter(review => review.status === "approved").length >= 2',
+                inputs: {
+                    reviews: [
+                        { status: 'approved' },
+                        { status: 'pending' },
+                        { status: 'approved' },
+                    ],
+                },
+                expectedResult: true,
+            },
+            {
+                scenario: 'array some',
+                condition: 'tags.some(tag => tag.startsWith("b") && tag.length === x)',
+                inputs: { tags: ['a', 'bb'], x: 2 },
+                expectedResult: true,
+            },
+            {
+                scenario: 'nested callbacks reading outer parameters',
+                condition: 'required.every(id => reviews.some(review => review.reviewer === id))',
+                inputs: {
+                    required: ['u1', 'u2'],
+                    reviews: [{ reviewer: 'u2' }, { reviewer: 'u1' }],
+                },
+                expectedResult: true,
+            },
+            {
+                scenario: 'callback parameter shadowing an input',
+                condition: 'tags.some(role => role === "b") && role === "admin"',
+                inputs: { tags: ['a', 'b'], role: 'admin' },
+                expectedResult: true,
+            },
+            {
+                scenario: 'array literal includes',
+                condition: '["admin", "editor"].includes(user.role)',
+                inputs: { user: { role: 'admin' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'array and string at',
+                condition: 'tags.at(-1).at(0)',
+                inputs: { tags: ['a', 'bc'] },
+                expectedResult: 'b',
+            },
+            {
+                scenario: 'string startsWith',
+                condition: 'user.role.startsWith("ad")',
+                inputs: { user: { role: 'admin' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'string endsWith',
+                condition: 'user.role.endsWith("min")',
+                inputs: { user: { role: 'admin' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'string includes',
+                condition: 'user.role.includes("dm")',
+                inputs: { user: { role: 'admin' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'string toLowerCase',
+                condition: 'user.role.toLowerCase() === "admin"',
+                inputs: { user: { role: 'ADMIN' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'string toUpperCase',
+                condition: 'user.role.toUpperCase() === "ADMIN"',
+                inputs: { user: { role: 'admin' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'string trim',
+                condition: 'user.role.trim() === "admin"',
+                inputs: { user: { role: '  admin  ' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'string length and index',
+                condition: 'user.role.length === 5 && user.role[0] === "a"',
+                inputs: { user: { role: 'admin' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'missing property',
+                condition: 'user.plan === undefined && missing === undefined',
+                inputs: { user: { role: 'admin' } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'boolean claim',
+                condition: 'visitor.claims.flag === true',
+                inputs: { visitor: { claims: { flag: true } } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'nested claims joined with ||',
+                condition: 'visitor.claims.group.a === true || visitor.claims.group.b === true',
+                inputs: { visitor: { claims: { group: { b: true } } } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'negated guard',
+                condition: "!visitor.claims.unsigned || visitor.claims.unsigned.region !== 'eu'",
+                inputs: { visitor: { claims: { unsigned: { region: 'us' } } } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'negated guard with a missing claim',
+                condition: "!visitor.claims.unsigned || visitor.claims.unsigned.region !== 'eu'",
+                inputs: { visitor: { claims: {} } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'key with a colon',
+                condition: "visitor.claims['custom:tier'] !== 'gold'",
+                inputs: { visitor: { claims: { 'custom:tier': 'silver' } } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'key with a colon and a missing claim',
+                condition: "visitor.claims['custom:tier'] !== 'gold'",
+                inputs: { visitor: { claims: {} } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'URL-style key',
+                condition: "visitor.claims['https://example.com/flag'] === true",
+                inputs: { visitor: { claims: { 'https://example.com/flag': true } } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'claim array includes',
+                condition: "visitor.claims.products.includes('a')",
+                inputs: { visitor: { claims: { products: ['a', 'b'] } } },
+                expectedResult: true,
+            },
+            {
+                scenario: 'array literal includes a claim',
+                condition: "['a', 'b'].includes(visitor.claims.org)",
+                inputs: { visitor: { claims: { org: 'a' } } },
+                expectedResult: true,
+            },
+            {
+                scenario: '&& guard with a dashed key',
+                condition:
+                    "visitor.claims.unsigned && visitor.claims.unsigned['early-access'] === true",
+                inputs: { visitor: { claims: { unsigned: { 'early-access': true } } } },
+                expectedResult: true,
+            },
         ])(
             'should properly evaluate/safeEvaluate a valid conditional expression: $scenario',
             ({ condition, inputs, expectedResult }) => {
@@ -84,11 +263,6 @@ describe('ExpressionRuntime', () => {
                 condition: 'while (1) {}',
                 inputs: {},
             },
-            {
-                scenario: 'unsafe expression',
-                condition: '[1, 2, 3].map(() => { while (1) {}})',
-                inputs: {},
-            },
         ];
 
         it.each(INVALID_EXPRESSSIONS)(
@@ -106,6 +280,303 @@ describe('ExpressionRuntime', () => {
                 expect(() => runtime.evaluate(condition, inputs)).toThrowError(ExpressionError);
             }
         );
+
+        it.each([
+            { scenario: 'string method', condition: 'visitor.claims.plan.startsWith("p")' },
+            { scenario: 'array method', condition: 'visitor.claims.products.includes("a")' },
+            { scenario: 'callback method', condition: 'visitor.claims.products.some(p => p)' },
+            { scenario: 'missing parent', condition: 'visitor.claims.org.name.toLowerCase()' },
+        ])(
+            'should give undefined when calling a method on a missing claim: $scenario',
+            ({ condition }) => {
+                const inputs = { visitor: { claims: {} } };
+
+                expect(runtime.evaluate(condition, inputs)).toBeUndefined();
+                expect(runtime.safeEvaluate(condition, inputs)).toEqual({ value: undefined });
+                expect(runtime.evaluateBoolean(condition, inputs)).toBe(false);
+            }
+        );
+    });
+
+    describe('unsafe expressions', () => {
+        // Each expression tries to call this function, which only an escape from the restrictions can reach.
+        const PAYLOAD = '__expressionPayload';
+        const CALL_PAYLOAD = `globalThis.${PAYLOAD}()`;
+        const payload = mock(() => true);
+
+        beforeEach(() => {
+            payload.mockClear();
+            Reflect.set(globalThis, PAYLOAD, payload);
+        });
+
+        afterEach(() => {
+            Reflect.deleteProperty(globalThis, PAYLOAD);
+        });
+
+        const UNSAFE_EXPRESSIONS = [
+            {
+                scenario: 'array key bypassing the constructor check',
+                condition: `({})[["constructor"]][["constructor"]]("${CALL_PAYLOAD}")()`,
+            },
+            {
+                scenario: 'array key on an input value',
+                condition: `user.role[["constructor"]][["constructor"]]("${CALL_PAYLOAD}")()`,
+            },
+            {
+                scenario: 'array key on a method',
+                condition: `"".includes[["constructor"]]("${CALL_PAYLOAD}")()`,
+            },
+            {
+                scenario: 'global access in a callback',
+                condition: `[1].some(() => ${CALL_PAYLOAD})`,
+            },
+            {
+                scenario: 'computed constructor key in a callback',
+                condition: `[1].some(x => x["constr" + "uctor"]["constr" + "uctor"]("${CALL_PAYLOAD}")())`,
+            },
+            {
+                scenario: 'computed constructor key in a map callback',
+                condition: `[1].map(x => x["constr" + "uctor"]["constr" + "uctor"]("${CALL_PAYLOAD}")())`,
+            },
+            {
+                scenario: 'arrow function called through implicit toString',
+                condition: `({ toString: () => ${CALL_PAYLOAD} }) + ""`,
+            },
+            { scenario: 'inherited property', condition: 'user.constructor' },
+            {
+                scenario: 'inherited property with an array key',
+                condition: 'user[["constructor"]]',
+            },
+            {
+                scenario: 'inherited property of a string',
+                condition: 'user.role.toString',
+                runtimeOnly: true,
+            },
+            { scenario: 'inherited property of a number', condition: 'count.constructor' },
+            { scenario: 'prototype access', condition: 'user.__proto__' },
+            { scenario: 'inherited variable', condition: 'toString', runtimeOnly: true },
+            { scenario: 'arrow function outside a callback', condition: '[() => 1].length' },
+            {
+                scenario: 'block-bodied arrow function',
+                condition: '[1, 2, 3].some(() => { while (1) {} })',
+            },
+            { scenario: 'function expression', condition: '[1].some(function () { return 1 })' },
+            { scenario: 'async arrow callback', condition: 'tags.some(async t => t)' },
+            {
+                scenario: 'async function callback',
+                condition: 'tags.some(async function (t) { return t })',
+            },
+            { scenario: 'immediately invoked async arrow', condition: '(async () => 1)()' },
+            { scenario: 'object literal', condition: '({ role: "admin" }).role' },
+            { scenario: 'constructor call', condition: 'new Date()' },
+            { scenario: 'eval', condition: `eval("${CALL_PAYLOAD}")` },
+            { scenario: 'eval as a method', condition: `globalThis.eval("${CALL_PAYLOAD}")` },
+            { scenario: 'new Function', condition: `new Function("${CALL_PAYLOAD}")()` },
+            { scenario: 'Function without new', condition: `Function("${CALL_PAYLOAD}")()` },
+            {
+                scenario: 'new on a function expression',
+                condition: `new function () { ${CALL_PAYLOAD} }()`,
+            },
+            { scenario: 'method outside the standard library', condition: '"a".padStart(1e9)' },
+            { scenario: 'string repeat', condition: 'user.role.repeat(1e9)' },
+            { scenario: 'string repeat in a callback', condition: 'tags.map(t => t.repeat(1e9))' },
+            { scenario: 'mutating array method', condition: 'tags.reverse()' },
+            {
+                scenario: 'callback for a method not taking one',
+                condition: 'tags.includes(t => t)',
+            },
+            {
+                scenario: 'inherited variable in a callback',
+                condition: 'tags.some(t => toString)',
+                runtimeOnly: true,
+            },
+            {
+                scenario: 'callback parameter named __proto__',
+                condition: 'tags.some(__proto__ => 1)',
+            },
+            {
+                scenario: 'callback parameter named constructor',
+                condition: 'tags.some(constructor => 1)',
+            },
+            {
+                scenario: 'expression deeper than the library limit',
+                condition: `${'!'.repeat(60)}true`,
+                runtimeOnly: true,
+            },
+            {
+                scenario: 'array literal longer than the library limit',
+                condition: `[${'1,'.repeat(10_001)}].length`,
+                runtimeOnly: true,
+            },
+            {
+                scenario: 'inherited property of a callback parameter',
+                condition: 'tags.some(t => t.constructor)',
+            },
+            { scenario: 'non-arrow callback', condition: 'tags.map(Function)' },
+            { scenario: 'callback with an extra argument', condition: 'tags.some(t => t, "a")' },
+            { scenario: 'missing callback', condition: 'tags.some()' },
+            {
+                scenario: 'too many nested callback calls',
+                condition:
+                    '[1, 2, 3, 4, 5, 6, 7, 8, 9, 10].map(a => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].map(b => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].map(c => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].map(d => d))))',
+                runtimeOnly: true,
+            },
+            { scenario: 'method on a plain object', condition: 'user.hasOwnProperty("role")' },
+            { scenario: 'method on a function', condition: '[1].some.call([1], n => n)' },
+            {
+                scenario: 'non-primitive argument',
+                condition: '[user].includes(user)',
+                runtimeOnly: true,
+            },
+            { scenario: 'regex operator', condition: 'user.role =~ /^ed/' },
+            { scenario: 'regex argument', condition: 'user.role.includes(/(a+)+b/)' },
+            { scenario: 'BigInt literal', condition: '2n ** 64n' },
+            {
+                scenario: 'BigInt literal in a callback',
+                condition: '[1, 2, 3, 4].some((n) => 9n ** 9n ** 9n)',
+            },
+            { scenario: 'BigInt literal in an array', condition: '[9n][0] ** 9n' },
+            { scenario: 'BigInt literal in a template', condition: '`${9n ** 9n ** 9n}`' },
+            { scenario: 'delete', condition: 'delete user.role' },
+            { scenario: 'assignment', condition: 'user.role = "admin"' },
+            { scenario: 'update', condition: 'count++' },
+        ];
+
+        it.each(UNSAFE_EXPRESSIONS)(
+            'should throw with evaluate and return the error with safeEvaluate: $scenario',
+            ({ condition }) => {
+                const evaluated = attempt(() => runtime.evaluate(condition, getInputs()));
+                const safeEvaluated = runtime.safeEvaluate(condition, getInputs());
+
+                expect(payload).not.toHaveBeenCalled();
+                expect(evaluated).toBeInstanceOf(ExpressionError);
+                expect(safeEvaluated.value).toBeUndefined();
+                expect(safeEvaluated.error).toBeInstanceOf(ExpressionError);
+            }
+        );
+
+        it.each(UNSAFE_EXPRESSIONS)(
+            'should evaluate to false with evaluateBoolean/evaluateBooleanAll: $scenario',
+            ({ condition }) => {
+                const evaluated = runtime.evaluateBoolean(condition, getInputs());
+                const evaluatedAll = runtime.evaluateBooleanAll(['true', condition], getInputs());
+
+                expect(payload).not.toHaveBeenCalled();
+                expect(evaluated).toBe(false);
+                expect(evaluatedAll).toBe(false);
+            }
+        );
+
+        it.each(UNSAFE_EXPRESSIONS)(
+            'should throw without executing code with evaluateTemplate: $scenario',
+            ({ condition }) => {
+                const evaluated = attempt(() =>
+                    runtime.evaluateTemplate(`Hello {{ ${condition} }}`, getInputs())
+                );
+
+                expect(payload).not.toHaveBeenCalled();
+                expect(evaluated).toBeInstanceOf(ExpressionError);
+            }
+        );
+
+        it.each(UNSAFE_EXPRESSIONS)('should not mutate the inputs: $scenario', ({ condition }) => {
+            const inputs = getInputs();
+            attempt(() => runtime.evaluate(condition, inputs));
+            expect(inputs).toEqual(getInputs());
+        });
+
+        it.each(UNSAFE_EXPRESSIONS)(
+            'should report the error when parsing, for editors: $scenario',
+            ({ condition, runtimeOnly }) => {
+                const parsed = attempt(() => runtime.parse(condition));
+                const { errors } = runtime.parseTemplate(`Hello {{ ${condition} }}`);
+
+                if (runtimeOnly) {
+                    // Depends on the values, so only enforced when evaluating.
+                    expect(parsed).not.toBeInstanceOf(Error);
+                    expect(errors).toEqual([]);
+                } else {
+                    expect(parsed).toBeInstanceOf(ExpressionError);
+                    expect((parsed as ExpressionError).location).toBeDefined();
+                    expect(errors).toHaveLength(1);
+                }
+            }
+        );
+
+        it.each(UNSAFE_EXPRESSIONS)(
+            'should not execute code when evaluating without validating first: $scenario',
+            ({ condition }) => {
+                const expression = parseExpressionAt(condition, 0, { ecmaVersion: 'latest' });
+                const evaluated = attempt(() => evaluateRestricted(expression, getInputs()));
+
+                expect(payload).not.toHaveBeenCalled();
+                expect(
+                    evaluated instanceof UnsafeExpressionError || evaluated instanceof RangeError
+                ).toBe(true);
+            }
+        );
+
+        it('should point the parse error at the offending token', () => {
+            const condition = 'user.role.padStart(10)';
+            const error = attempt(() => runtime.parse(condition)) as ExpressionError;
+
+            expect(error.message).toBe('Method "padStart" is not supported');
+            expect(error.location).toEqual({ line: 1, column: 10 });
+            expect(condition.slice(error.token?.start, error.token?.end)).toBe('padStart');
+        });
+
+        it('should keep the location of the error when evaluating', () => {
+            const condition = 'user.role.padStart(10)';
+            const error = attempt(() => runtime.evaluate(condition, getInputs()));
+
+            expect(error).toBeInstanceOf(UnsafeExpressionError);
+            expect((error as ExpressionError).location).toEqual({ line: 1, column: 10 });
+        });
+
+        it('should explain why async callbacks are rejected', () => {
+            const error = attempt(() => runtime.parse('tags.some(async t => t)'));
+
+            expect((error as ExpressionError).message).toBe('Async functions are not supported');
+        });
+
+        it('should not validate when parsing loosely for autocomplete', () => {
+            expect(() => runtime.parse('user.constructor', { loose: true })).not.toThrow();
+        });
+
+        it.each(['constructor', '__proto__', 'prototype', '__defineGetter__', '__lookupGetter__'])(
+            'should not read an own "%s" key of the inputs',
+            (key) => {
+                // JSON.parse creates own properties, even for `__proto__`.
+                const inputs = JSON.parse(`{ "data": { "${key}": "value" }, "${key}": "value" }`);
+
+                expect(() => runtime.evaluate(`data["${key}"]`, inputs)).toThrow(ExpressionError);
+                expect(() => runtime.evaluate(key, inputs)).toThrow(ExpressionError);
+                expect(runtime.evaluateBoolean(`data["${key}"] === "value"`, inputs)).toBe(false);
+            }
+        );
+
+        it('should limit the number of callback calls per evaluation', () => {
+            const condition = 'items.map(item => item).length > 0';
+            const atLimit = { items: Array.from({ length: MAX_CALLBACK_CALLS }, (_, i) => i) };
+            const overLimit = { items: [...atLimit.items, MAX_CALLBACK_CALLS] };
+
+            expect(runtime.evaluate(condition, atLimit)).toBe(true);
+            // The budget is per evaluation, not shared across evaluations.
+            expect(runtime.evaluate(condition, atLimit)).toBe(true);
+            expect(() => runtime.evaluate(condition, overLimit)).toThrow(ExpressionError);
+            expect(runtime.evaluateBoolean(condition, overLimit)).toBe(false);
+        });
+
+        it('should only allow the standard library offered in the editor and reviewed additions', () => {
+            const stringMethods = SymbolString().methods.map((method) => method.name);
+            const arrayMethods = SymbolArray({ items: SymbolString() }).methods.map(
+                (method) => method.name
+            );
+
+            // Extend only after reviewing that a method is safe (see `ALLOWED_METHODS`).
+            expect(ALLOWED_METHODS.string).toEqual(new Set(stringMethods));
+            expect(ALLOWED_METHODS.array).toEqual(new Set([...arrayMethods, 'filter', 'map']));
+        });
     });
 
     describe('parse', () => {
@@ -153,6 +624,49 @@ describe('ExpressionRuntime', () => {
         );
     });
 
+    describe('getVariables', () => {
+        it.each([
+            {
+                scenario: 'single variable',
+                condition: 'isBetaUser === true',
+                expectedVariables: ['isBetaUser'],
+            },
+            {
+                scenario: 'multiple variables',
+                condition: 'useProductA && !isBetaUser',
+                expectedVariables: ['useProductA', 'isBetaUser'],
+            },
+            {
+                scenario: 'member expression',
+                condition: 'user.role === "admin"',
+                expectedVariables: ['user.role'],
+            },
+            {
+                scenario: 'nested member expression with method call',
+                condition: 'products.includes("productA") && userSegments.alpha',
+                expectedVariables: ['products.includes', 'userSegments.alpha'],
+            },
+        ])(
+            'should return variables used in expression: $scenario',
+            ({ condition, expectedVariables }) => {
+                expect(runtime.getVariables(condition)).toEqual(expectedVariables);
+            }
+        );
+
+        it.each([
+            {
+                scenario: 'invalid syntax',
+                condition: 't}=d',
+            },
+            {
+                scenario: 'non conditional expression',
+                condition: 'const a = 1;',
+            },
+        ])('should return an empty array for invalid expressions: $scenario', ({ condition }) => {
+            expect(runtime.getVariables(condition)).toEqual([]);
+        });
+    });
+
     describe.skip('generate', () => {
         it.each([
             {

packages/expr/src/autocomplete.ts

@@ -11,7 +11,6 @@ import type {
 } 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';
@@ -312,7 +311,7 @@ export class AutoComplete {
         node: BinaryExpression,
         cursorOffset: number,
         context: SymbolsTable
-    ): Array<AutocompleteLiteralValueSuggestion> {
+    ): AutocompleteLiteralValueSuggestion[] {
         const { left, right } = node;
 
         if (left.type !== 'MemberExpression' && left.type !== 'Identifier') {
@@ -431,7 +430,7 @@ export class AutoComplete {
         node: AnyNode,
         cursorOffset: number,
         context: SymbolsTable
-    ): Array<AutocompleteOperatorSuggestion> {
+    ): AutocompleteOperatorSuggestion[] {
         if (node.type === 'Literal') {
             const parent = findParentNode(node, ast);
 
@@ -496,7 +495,7 @@ export class AutoComplete {
      */
     private getOperatorSuggestionsForSymbol(
         symbol: ExtractSymbolDef<SymbolType>
-    ): Array<AutocompleteOperatorSuggestion> {
+    ): AutocompleteOperatorSuggestion[] {
         switch (symbol.type) {
             case SymbolType.Number:
             case SymbolType.Boolean:
@@ -526,7 +525,7 @@ export class AutoComplete {
             case SymbolType.Function:
                 return this.getOperatorSuggestionsForSymbol(symbol.returns);
             case SymbolType.Union: {
-                return symbol.members.reduce<Array<AutocompleteOperatorSuggestion>>((prev, cur) => {
+                return symbol.members.reduce<AutocompleteOperatorSuggestion[]>((prev, cur) => {
                     prev.push(...this.getOperatorSuggestionsForSymbol(cur));
                     return prev;
                 }, []);

packages/expr/src/input-values.ts

@@ -1,4 +1,5 @@
 import type { JSONSchema7 } from 'json-schema';
+
 import { filterOutNullable } from './utils';
 
 type InputValuesType =

packages/expr/src/restricted/evaluate.ts

@@ -0,0 +1,236 @@
+import type {
+    ArrowFunctionExpression,
+    CallExpression,
+    Expression,
+    Identifier,
+    Literal,
+    MemberExpression,
+    Node,
+    UnaryExpression,
+} from 'acorn';
+import evalESTreeExpr from 'eval-estree-expression';
+
+import {
+    ALLOWED_METHODS,
+    CALLBACK_METHODS,
+    MAX_CALLBACK_CALLS,
+    UNSAFE_KEYS,
+    UnsafeExpressionError,
+    getCallbackParams,
+} from './rules';
+
+/**
+ * Evaluate a parsed expression with the restrictions, enforcing the rules that depend on values.
+ */
+export function evaluateRestricted(expression: Expression, inputs: object): unknown {
+    return evalESTreeExpr.evaluate.sync<Expression>(expression, inputs, {
+        // The library's own function support compiles code with `Function()`: calls and
+        // arrow functions are only handled by our visitors.
+        functions: false,
+        withMembers: true,
+        visitors: RESTRICTED_VISITORS,
+    });
+}
+
+/**
+ * Callback calls so far, per evaluator (the library creates one per evaluation).
+ */
+const callbackCalls = new WeakMap<object, number>();
+
+type Visit = (node: Node, context: object, parent?: Node) => unknown;
+type Evaluator = { visit: Visit };
+
+/**
+ * Visitors overriding eval-estree-expression's defaults so that expressions can only read own
+ * properties of plain data and call the methods of the standard library.
+ */
+const RESTRICTED_VISITORS = {
+    Identifier(this: Evaluator, node: Identifier, context: object): unknown {
+        return readVariable(context, node.name);
+    },
+
+    MemberExpression(this: Evaluator, node: MemberExpression, context: object): unknown {
+        const object = this.visit(node.object, context, node);
+        const key = node.computed
+            ? this.visit(node.property, context, node)
+            : (node.property as Identifier).name;
+
+        // Reject rather than coerce, so that keys like `["constructor"]` can't slip through.
+        if (typeof key !== 'string' && typeof key !== 'number') {
+            throw new UnsafeExpressionError('Property keys must be strings or numbers');
+        }
+        return readOwnProperty(object, String(key));
+    },
+
+    CallExpression(this: Evaluator, node: CallExpression, context: object): unknown {
+        const callee = node.callee;
+        if (callee.type !== 'MemberExpression' || callee.computed || callee.optional) {
+            throw new UnsafeExpressionError('Only method calls are supported');
+        }
+
+        const method = (callee.property as Identifier).name;
+        const receiver = this.visit(callee.object, context, callee);
+
+        // Like reading a property of a missing claim, calling a method on one gives `undefined`.
+        if (
+            (receiver === null || receiver === undefined) &&
+            (ALLOWED_METHODS.string.has(method) || ALLOWED_METHODS.array.has(method))
+        ) {
+            return undefined;
+        }
+
+        const fn = getAllowedMethod(receiver, method);
+        if (!fn) {
+            throw new UnsafeExpressionError(`Method "${method}" is not supported`);
+        }
+
+        if (CALLBACK_METHODS.has(method)) {
+            const [callback] = node.arguments;
+            if (node.arguments.length !== 1 || callback?.type !== 'ArrowFunctionExpression') {
+                throw new UnsafeExpressionError(`"${method}" only accepts an arrow function`);
+            }
+            return Reflect.apply(fn, receiver, [createCallback(this, callback, context)]);
+        }
+
+        const args = node.arguments.map((arg) => {
+            if (arg.type === 'SpreadElement') {
+                throw new UnsafeExpressionError('Spread arguments are not supported');
+            }
+            const value = this.visit(arg, context, node);
+            if (!isPrimitive(value)) {
+                throw new UnsafeExpressionError('Only primitive values can be arguments');
+            }
+            return value;
+        });
+
+        return Reflect.apply(fn, receiver, args);
+    },
+
+    ArrowFunctionExpression(): never {
+        throw new UnsafeExpressionError('Arrow functions are only supported as callbacks');
+    },
+
+    FunctionExpression(): never {
+        throw new UnsafeExpressionError('Functions are not supported');
+    },
+
+    ObjectExpression(): never {
+        throw new UnsafeExpressionError('Object literals are not supported');
+    },
+
+    Literal(node: Literal): unknown {
+        // Regexes are only useful to the library's `=~` operator, and BigInt exponentiation can hang.
+        if (node.regex || typeof node.value === 'bigint') {
+            throw new UnsafeExpressionError('Regex and BigInt literals are not supported');
+        }
+        return node.value;
+    },
+
+    UnaryExpression(this: Evaluator, node: UnaryExpression, context: object): unknown {
+        // The library implements `delete` by mutating the inputs.
+        if (node.operator === 'delete') {
+            throw new UnsafeExpressionError('"delete" is not supported');
+        }
+        return Object.getPrototypeOf(this).UnaryExpression.call(this, node, context);
+    },
+
+    AssignmentExpression(): never {
+        throw new UnsafeExpressionError('Assignments are not supported');
+    },
+
+    UpdateExpression(): never {
+        throw new UnsafeExpressionError('Update expressions are not supported');
+    },
+
+    NewExpression(): never {
+        throw new UnsafeExpressionError('"new" is not supported');
+    },
+
+    TaggedTemplateExpression(): never {
+        throw new UnsafeExpressionError('Tagged templates are not supported');
+    },
+
+    ThisExpression(): never {
+        throw new UnsafeExpressionError('"this" is not supported');
+    },
+};
+
+/**
+ * Create a callback evaluating the arrow function's body with the evaluator, instead of compiling it.
+ */
+function createCallback(evaluator: Evaluator, node: ArrowFunctionExpression, context: object) {
+    const params = getCallbackParams(node);
+
+    return (...args: unknown[]) => {
+        const calls = (callbackCalls.get(evaluator) ?? 0) + 1;
+        if (calls > MAX_CALLBACK_CALLS) {
+            throw new UnsafeExpressionError('Too many callback calls');
+        }
+        callbackCalls.set(evaluator, calls);
+
+        const variables = new Map(params.map((name, index) => [name, args[index]]));
+        return evaluator.visit(node.body, new CallbackScope(variables, context), node);
+    };
+}
+
+/**
+ * Variables of a callback call, falling back to the enclosing scope.
+ * A Map avoids copying the inputs on each call.
+ */
+class CallbackScope {
+    constructor(
+        readonly variables: Map<string, unknown>,
+        readonly parent: object
+    ) {}
+}
+
+function readVariable(scope: object, name: string): unknown {
+    if (UNSAFE_KEYS.has(name)) {
+        throw new UnsafeExpressionError(`"${name}" is not accessible`);
+    }
+    if (scope instanceof CallbackScope) {
+        return scope.variables.has(name)
+            ? scope.variables.get(name)
+            : readVariable(scope.parent, name);
+    }
+    return readOwnProperty(scope, name);
+}
+
+/**
+ * Read an own property, treating any attempt to reach an inherited one (e.g. `constructor`) as unsafe.
+ */
+function readOwnProperty(object: unknown, key: string): unknown {
+    if (UNSAFE_KEYS.has(key)) {
+        throw new UnsafeExpressionError(`Property "${key}" is not accessible`);
+    }
+    if (object === null || object === undefined) {
+        return undefined;
+    }
+    if (typeof object === 'function') {
+        throw new UnsafeExpressionError('Functions are not accessible');
+    }
+
+    // Wrapping primitives exposes string indexes and `length` as own properties.
+    const target = Object(object);
+    if (Object.hasOwn(target, key)) {
+        return target[key];
+    }
+    if (key in target) {
+        throw new UnsafeExpressionError(`Property "${key}" is not accessible`);
+    }
+    return undefined;
+}
+
+function getAllowedMethod(receiver: unknown, method: string): Function | null {
+    if (typeof receiver === 'string' && ALLOWED_METHODS.string.has(method)) {
+        return Reflect.get(String.prototype, method);
+    }
+    if (Array.isArray(receiver) && ALLOWED_METHODS.array.has(method)) {
+        return Reflect.get(Array.prototype, method);
+    }
+    return null;
+}
+
+function isPrimitive(value: unknown): boolean {
+    return value === null || (typeof value !== 'object' && typeof value !== 'function');
+}

packages/expr/src/restricted/index.ts

@@ -0,0 +1,3 @@
+export { evaluateRestricted } from './evaluate';
+export { ALLOWED_METHODS, MAX_CALLBACK_CALLS, UnsafeExpressionError } from './rules';
+export { validateExpression } from './validate';

packages/expr/src/restricted/rules.ts

@@ -0,0 +1,78 @@
+import type { AnyNode, ArrowFunctionExpression } from 'acorn';
+
+import { ExpressionError } from '../errors';
+
+/**
+ * Methods that expressions are allowed to call, per receiver type.
+ * Must include the standard library offered in the editor (see `symbols.ts`). Only add methods
+ * after review: they must not mutate their receiver, and their output must stay bounded by their input.
+ */
+export const ALLOWED_METHODS = {
+    string: new Set([
+        'at',
+        'endsWith',
+        'includes',
+        'startsWith',
+        'toLowerCase',
+        'toUpperCase',
+        'trim',
+    ]),
+    array: new Set(['at', 'every', 'filter', 'includes', 'map', 'some']),
+};
+
+/**
+ * Array methods taking a callback, the only place where arrow functions are allowed.
+ */
+export const CALLBACK_METHODS = new Set(['every', 'filter', 'map', 'some']);
+
+/**
+ * Maximum number of callback calls in a single evaluation, as nested callbacks multiply and
+ * visitors control the size of unsigned claims. Enough for a pass over an identity provider's
+ * group claim (capped around 200 entries), or a small nested pair of arrays.
+ */
+export const MAX_CALLBACK_CALLS = 250;
+
+/**
+ * Names never readable as variables or properties, even as own properties of the inputs.
+ * Replaces (and extends) the library's own denylist, as our visitors override the ones applying it.
+ */
+export const UNSAFE_KEYS = new Set([
+    '__defineGetter__',
+    '__defineSetter__',
+    '__lookupGetter__',
+    '__lookupSetter__',
+    '__proto__',
+    'constructor',
+    'prototype',
+]);
+
+/**
+ * Thrown when an expression uses something the restrictions don't allow.
+ */
+export class UnsafeExpressionError extends ExpressionError {}
+
+/**
+ * Create an error pointing at the node, so that editors can highlight it.
+ */
+export function unsupported(node: AnyNode, message: string): UnsafeExpressionError {
+    return new UnsafeExpressionError(message, node.loc?.start);
+}
+
+/**
+ * Parameter names of an arrow function, if it has the shape allowed for callbacks.
+ */
+export function getCallbackParams(node: ArrowFunctionExpression): string[] {
+    if (node.async) {
+        throw unsupported(node, 'Async functions are not supported');
+    }
+    if (!node.expression) {
+        throw unsupported(node, 'Only single-expression arrow functions are supported');
+    }
+
+    return node.params.map((param) => {
+        if (param.type !== 'Identifier' || UNSAFE_KEYS.has(param.name)) {
+            throw unsupported(param, 'Only simple arrow function parameters are supported');
+        }
+        return param.name;
+    });
+}

packages/expr/src/restricted/validate.ts

@@ -0,0 +1,137 @@
+import type { AnyNode, CallExpression, Identifier } from 'acorn';
+
+import {
+    ALLOWED_METHODS,
+    CALLBACK_METHODS,
+    UNSAFE_KEYS,
+    getCallbackParams,
+    unsupported,
+} from './rules';
+
+/**
+ * Check an expression against the restrictions without evaluating it, so that editors can report
+ * violations. Rules depending on values (receiver types, inherited properties, limits) are only
+ * enforced by `evaluateRestricted`.
+ */
+export function validateExpression(node: AnyNode): void {
+    switch (node.type) {
+        case 'Literal':
+            if (node.regex || typeof node.value === 'bigint') {
+                throw unsupported(
+                    node,
+                    'Regular expressions and BigInt literals are not supported'
+                );
+            }
+            return;
+        case 'Identifier':
+            return assertSafeKey(node.name, node);
+        case 'TemplateLiteral':
+            return node.expressions.forEach(validateExpression);
+        case 'ArrayExpression':
+            for (const element of node.elements) {
+                if (element) {
+                    validateExpression(
+                        element.type === 'SpreadElement' ? element.argument : element
+                    );
+                }
+            }
+            return;
+        case 'UnaryExpression':
+            if (node.operator === 'delete') {
+                throw unsupported(node, '"delete" is not supported');
+            }
+            return validateExpression(node.argument);
+        case 'BinaryExpression':
+        case 'LogicalExpression':
+            validateExpression(node.left);
+            return validateExpression(node.right);
+        case 'ConditionalExpression':
+            validateExpression(node.test);
+            validateExpression(node.consequent);
+            return validateExpression(node.alternate);
+        case 'SequenceExpression':
+            return node.expressions.forEach(validateExpression);
+        case 'MemberExpression':
+            validateExpression(node.object);
+            if (!node.computed) {
+                return assertSafeKey((node.property as Identifier).name, node.property);
+            }
+            if (node.property.type === 'Literal') {
+                return assertSafeKey(String(node.property.value), node.property);
+            }
+            if (node.property.type === 'ArrayExpression') {
+                throw unsupported(node.property, 'Property keys must be strings or numbers');
+            }
+            return validateExpression(node.property);
+        case 'CallExpression':
+            return validateCall(node);
+        case 'ArrowFunctionExpression':
+            throw unsupported(node, 'Arrow functions are only supported as callbacks');
+        case 'ObjectExpression':
+            throw unsupported(node, 'Object literals are not supported');
+        case 'AssignmentExpression':
+            // `a =~ /regex/` parses as an assignment of `~/regex/`.
+            throw unsupported(
+                node,
+                node.right.type === 'UnaryExpression' && node.right.operator === '~'
+                    ? 'The "=~" regex operator is not supported'
+                    : 'Assignments are not supported'
+            );
+        default:
+            throw unsupported(
+                node,
+                UNSUPPORTED_SYNTAX[node.type] ?? `${node.type} is not supported`
+            );
+    }
+}
+
+/**
+ * Errors shown to authors for rejected syntax.
+ */
+const UNSUPPORTED_SYNTAX: Partial<Record<AnyNode['type'], string>> = {
+    AwaitExpression: '"await" is not supported',
+    ChainExpression: 'Optional chaining ("?.") is not supported',
+    ClassExpression: 'Classes are not supported',
+    FunctionExpression: 'Functions are not supported',
+    ImportExpression: '"import" is not supported',
+    NewExpression: '"new" is not supported',
+    TaggedTemplateExpression: 'Tagged templates are not supported',
+    ThisExpression: '"this" is not supported',
+    UpdateExpression: '"++" and "--" are not supported',
+    YieldExpression: '"yield" is not supported',
+};
+
+function validateCall(node: CallExpression): void {
+    const callee = node.callee;
+    if (callee.type !== 'MemberExpression' || callee.computed || node.optional) {
+        throw unsupported(node, 'Only method calls are supported');
+    }
+    validateExpression(callee.object);
+
+    const method = (callee.property as Identifier).name;
+    if (!ALLOWED_METHODS.string.has(method) && !ALLOWED_METHODS.array.has(method)) {
+        throw unsupported(callee.property, `Method "${method}" is not supported`);
+    }
+
+    if (CALLBACK_METHODS.has(method)) {
+        const [callback] = node.arguments;
+        if (node.arguments.length !== 1 || callback?.type !== 'ArrowFunctionExpression') {
+            throw unsupported(node, `"${method}" only accepts an arrow function`);
+        }
+        getCallbackParams(callback);
+        return validateExpression(callback.body);
+    }
+
+    for (const arg of node.arguments) {
+        if (arg.type === 'SpreadElement') {
+            throw unsupported(arg, 'Spread arguments are not supported');
+        }
+        validateExpression(arg);
+    }
+}
+
+function assertSafeKey(key: string, node: AnyNode): void {
+    if (UNSAFE_KEYS.has(key)) {
+        throw unsupported(node, `"${key}" is not accessible`);
+    }
+}

packages/expr/src/runtime.ts

@@ -11,10 +11,11 @@ import {
 import { parse as parseLoose } from 'acorn-loose';
 import escodegen from 'escodegen';
 import evalESTreeExpr from 'eval-estree-expression';
-const { evaluate } = evalESTreeExpr;
+const { variables } = evalESTreeExpr;
 
 import { AutoComplete } from './autocomplete';
 import { ExpressionError } from './errors';
+import { UnsafeExpressionError, evaluateRestricted, validateExpression } from './restricted';
 import type { SymbolsTable } from './symbols';
 import type { TemplatePart } from './template';
 import { parseTemplate as parseTemplateParts } from './template';
@@ -39,6 +40,7 @@ export class ExpressionRuntime {
 
     /**
      * Evaluates an expression based on the given inputs/context.
+     * Throws an `ExpressionError` for invalid expressions, including those the restrictions don't allow.
      */
     public evaluate(expr: string, inputs: object): unknown {
         try {
@@ -48,12 +50,12 @@ export class ExpressionRuntime {
                 throw new ExpressionError('Invalid nodes found when parsing');
             }
 
-            return evaluate.sync<Expression>(parsed.result, inputs, {
-                functions: true,
-                withMembers: true,
-                generate: escodegen.generate,
-            });
+            return evaluateRestricted(parsed.result, inputs);
         } catch (error) {
+            // Keep the location, so that editors can point at the offending token.
+            if (error instanceof UnsafeExpressionError) {
+                throw error;
+            }
             throw error instanceof Error
                 ? new ExpressionError(error.message)
                 : new ExpressionError('Unexpected error');
@@ -162,6 +164,28 @@ export class ExpressionRuntime {
             .join('');
     }
 
+    /**
+     * Given an expression, returns a list of variables used in the expression.
+     */
+    public getVariables(expr: string): string[] {
+        try {
+            const parsed = this.parse(expr);
+
+            if (parsed.invalidNodes.length > 0) {
+                throw new ExpressionError('Invalid nodes found when parsing');
+            }
+
+            return variables(parsed.result, {
+                functions: true,
+                withMembers: true,
+                generate: escodegen.generate,
+            });
+        } catch (error) {
+            this.#logger.error(`Error while parsing expression ${expr} to get variables`, error);
+            return [];
+        }
+    }
+
     /**
      * Parses a binary expression and returns an @ExpressionParserResult.
      */
@@ -191,6 +215,11 @@ export class ExpressionRuntime {
             // Return information on the other nodes as invalid nodes
             const invalidNodes = ast.body.filter(filterOutModuleDeclarationStatement);
 
+            // Loose parsing serves autocomplete on partial expressions, which are expected to be incomplete.
+            if (!options.loose) {
+                validateRestrictedExpression(expr, statement.expression);
+            }
+
             return {
                 result: statement.expression,
                 invalidNodes,
@@ -243,6 +272,25 @@ function createExpressionErrorFromSyntaxError(
 
     return new ExpressionError(errorMessage, loc, token);
 }
+
+/**
+ * Validate an expression against the restrictions, pointing the error at the offending token for editors.
+ */
+function validateRestrictedExpression(code: string, expression: Expression): void {
+    try {
+        validateExpression(expression);
+    } catch (error) {
+        if (error instanceof UnsafeExpressionError && error.location) {
+            throw new UnsafeExpressionError(
+                error.message,
+                error.location,
+                getTokenAtLoc(code, error.location)
+            );
+        }
+        throw error;
+    }
+}
+
 function getTokenAtLoc(code: string, errorLoc: Position): Token | undefined {
     const tokens = tokenizer(code, {
         ecmaVersion: 'latest',

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

@@ -255,8 +255,12 @@ describe('ExpressionRuntime', () => {
                 childrenRefs: [
                     'visitor.claims.key.length',
                     'visitor.claims.key.at',
+                    'visitor.claims.key.startsWith',
                     'visitor.claims.key.endsWith',
                     'visitor.claims.key.includes',
+                    'visitor.claims.key.toLowerCase',
+                    'visitor.claims.key.toUpperCase',
+                    'visitor.claims.key.trim',
                 ],
             });
 
@@ -301,8 +305,12 @@ describe('ExpressionRuntime', () => {
                 childrenRefs: [
                     'visitor.claims.flags.FLAG1.length',
                     'visitor.claims.flags.FLAG1.at',
+                    'visitor.claims.flags.FLAG1.startsWith',
                     'visitor.claims.flags.FLAG1.endsWith',
                     'visitor.claims.flags.FLAG1.includes',
+                    'visitor.claims.flags.FLAG1.toLowerCase',
+                    'visitor.claims.flags.FLAG1.toUpperCase',
+                    'visitor.claims.flags.FLAG1.trim',
                 ],
             });
 
@@ -318,8 +326,12 @@ describe('ExpressionRuntime', () => {
                 childrenRefs: [
                     'visitor.claims.flags.FLAG2.length',
                     'visitor.claims.flags.FLAG2.at',
+                    'visitor.claims.flags.FLAG2.startsWith',
                     'visitor.claims.flags.FLAG2.endsWith',
                     'visitor.claims.flags.FLAG2.includes',
+                    'visitor.claims.flags.FLAG2.toLowerCase',
+                    'visitor.claims.flags.FLAG2.toUpperCase',
+                    'visitor.claims.flags.FLAG2.trim',
                 ],
             });
 

packages/expr/src/symbols/symbols.ts

@@ -156,6 +156,31 @@ const StandardLibrary: Partial<
                     members: [SymbolString(), SymbolUndefined()],
                 }),
             }),
+            SymbolFunction({
+                name: 'startsWith',
+                description: `Returns true if the given characters are found at the beginning of the string, including when searchString 
+            is an empty string. Otherwise returns false.`,
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith',
+                args: [
+                    SymbolString({
+                        name: 'searchString',
+                        description: `The characters to be searched for at the start of this string. Cannot be a regex.
+                    All values that are not regexes are coerced to strings, so omitting it or passing undefined causes startsWith() to search for 
+                    the string "undefined", which is rarely what you want.`,
+                    }),
+                    OptionalFunctionArg(
+                        SymbolNumber({
+                            name: 'position',
+                            description: `The start position at which searchString is expected to be found 
+                    (the index of searchString's first character). Defaults to 0.`,
+                        })
+                    ),
+                ],
+                returns: SymbolBoolean({
+                    description: `true if the given characters are found at the beginning of the string, including when searchString is an empty string; 
+                otherwise, false.`,
+                }),
+            }),
             SymbolFunction({
                 name: 'endsWith',
                 description: `Returns true if the sequence of elements of searchString converted to a String is the same as the corresponding 
@@ -205,6 +230,39 @@ const StandardLibrary: Partial<
                 otherwise, false.`,
                 }),
             }),
+            SymbolFunction({
+                name: 'toLowerCase',
+                description:
+                    'Returns the value of the string converted to lower case. toLowerCase() does not affect the value of the string str itself.',
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toLowerCase',
+                args: [],
+                returns: SymbolString({
+                    description:
+                        'A new string representing the calling string converted to lower case.',
+                }),
+            }),
+            SymbolFunction({
+                name: 'toUpperCase',
+                description:
+                    'Returns the value of the string converted to uppercase. toUpperCase() does not affect the value of the string str itself.',
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase',
+                args: [],
+                returns: SymbolString({
+                    description:
+                        'A new string representing the calling string converted to upper case.',
+                }),
+            }),
+            SymbolFunction({
+                name: 'trim',
+                description:
+                    'Returns new string representing str stripped of whitespace from both its beginning and end.',
+                link: 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trim',
+                args: [],
+                returns: SymbolString({
+                    description:
+                        'A new string representing str stripped of whitespace from both its beginning and end.',
+                }),
+            }),
         ],
     },
     [SymbolType.Array]: (arraySymbolDef: ArraySymbolDef) => ({