From 39316fc2055b46cd1e13ff22ae9a36fbd08834f9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Greg=20Berg=C3=A9?= <berge.greg@gmail.com>
Date: Mon, 14 Sep 2026 12:01:04 +0200
Subject: [PATCH] Add agent actions to the prompt block (#4610)

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
---
 .changeset/eighty-donkeys-tease.md            |   5 +
 .../DocumentView/Prompt/PromptActions.tsx     | 156 ++++++++++++++++++
 .../DocumentView/Prompt/PromptClient.tsx      | 110 +-----------
 .../DocumentView/Prompt/promptAction.ts       |  95 +++++++++++
 .../src/components/utils/getURLForLLM.ts      |   4 +-
 packages/gitbook/src/lib/ai-agents.test.ts    |  48 ++++++
 packages/gitbook/src/lib/ai-agents.ts         |  70 ++++++++
 7 files changed, 377 insertions(+), 111 deletions(-)
 create mode 100644 .changeset/eighty-donkeys-tease.md
 create mode 100644 packages/gitbook/src/components/DocumentView/Prompt/PromptActions.tsx
 create mode 100644 packages/gitbook/src/components/DocumentView/Prompt/promptAction.ts
 create mode 100644 packages/gitbook/src/lib/ai-agents.test.ts
 create mode 100644 packages/gitbook/src/lib/ai-agents.ts

diff --git a/.changeset/eighty-donkeys-tease.md b/.changeset/eighty-donkeys-tease.md
new file mode 100644
index 000000000..c1936d346
--- /dev/null
+++ b/.changeset/eighty-donkeys-tease.md
@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Give the prompt block a default "Copy prompt" action alongside "Open in Claude", "Open in Codex" and "Open in Cursor", and remember the visitor's last pick across every prompt block.
diff --git a/packages/gitbook/src/components/DocumentView/Prompt/PromptActions.tsx b/packages/gitbook/src/components/DocumentView/Prompt/PromptActions.tsx
new file mode 100644
index 000000000..f37e01b49
--- /dev/null
+++ b/packages/gitbook/src/components/DocumentView/Prompt/PromptActions.tsx
@@ -0,0 +1,156 @@
+'use client';
+
+import React from 'react';
+
+import { Icon } from '@gitbook/icons';
+
+import { type PromptActionId, setPromptAction, usePromptAction } from './promptAction';
+import {
+    Button,
+    ButtonGroup,
+    DropdownMenu,
+    DropdownMenuItem,
+    ToggleChevron,
+} from '@/components/primitives';
+import { tString, useLanguage } from '@/intl/client';
+import { AI_AGENTS, getAIAgent } from '@/lib/ai-agents';
+import { tcls } from '@/lib/tailwind';
+
+/** How long the copy button shows its confirmation. */
+const COPIED_MESSAGE_DURATION = 1000;
+
+/**
+ * Actions of a prompt block: copying the prompt, or handing it to a coding agent. The visitor's
+ * last pick becomes the main button, here and in every other prompt block they come across.
+ */
+export function PromptActions(props: { prompt: string; openInAIProviders: boolean }) {
+    const { prompt, openInAIProviders } = props;
+    const language = useLanguage();
+    const selectedAction = usePromptAction();
+    const [copied, setCopied] = React.useState(false);
+
+    React.useEffect(() => {
+        if (!copied) {
+            return;
+        }
+
+        const timeout = setTimeout(() => {
+            setCopied(false);
+        }, COPIED_MESSAGE_DURATION);
+
+        return () => {
+            clearTimeout(timeout);
+        };
+    }, [copied]);
+
+    const copyPrompt = () => {
+        navigator.clipboard.writeText(prompt);
+        setCopied(true);
+    };
+
+    // The pick follows the visitor from site to site, so fall back to copying wherever the agent
+    // actions are turned off — and with nothing to hand over, an agent link would open an agent on
+    // an empty prompt.
+    const action: PromptActionId = openInAIProviders && prompt ? selectedAction : 'copy';
+    const agent = action === 'copy' ? null : getAIAgent(action);
+
+    const mainButton = agent ? (
+        <Button
+            variant="secondary"
+            size="xsmall"
+            icon={agent.icon}
+            label={tString(language, 'open_in', agent.label)}
+            href={agent.getURL(prompt)}
+            // The OS picks the deep link up and the page stays put, where `_blank` would strand the
+            // visitor on a tab that never loads anything.
+            target="_self"
+        />
+    ) : (
+        <Button
+            variant="secondary"
+            size="xsmall"
+            icon={copied ? 'check' : 'copy'}
+            label={copied ? tString(language, 'code_copied') : tString(language, 'prompt_copy')}
+            disabled={!prompt}
+            onClick={copyPrompt}
+        />
+    );
+
+    return (
+        // Lifted above the header's overlay button, which otherwise swallows the clicks.
+        <div className="relative z-20 flex shrink-0 items-center gap-2">
+            {openInAIProviders ? (
+                <ButtonGroup>
+                    {mainButton}
+                    <DropdownMenu
+                        align="end"
+                        className="!min-w-48 max-w-max"
+                        button={
+                            <Button
+                                label={tString(language, 'more')}
+                                size="xsmall"
+                                variant="secondary"
+                                truncate={false}
+                                disabled={!prompt}
+                            >
+                                <span className="flex items-center gap-1.5">
+                                    <AgentIconStack />
+                                    <ToggleChevron className="size-text-sm" />
+                                </span>
+                            </Button>
+                        }
+                    >
+                        <DropdownMenuItem
+                            active={action === 'copy'}
+                            leadingIcon="copy"
+                            onClick={() => {
+                                setPromptAction('copy');
+                                copyPrompt();
+                            }}
+                        >
+                            {tString(language, 'prompt_copy')}
+                        </DropdownMenuItem>
+                        {AI_AGENTS.map((item) => (
+                            <DropdownMenuItem
+                                key={item.id}
+                                active={action === item.id}
+                                leadingIcon={item.icon}
+                                href={item.getURL(prompt)}
+                                target="_self"
+                                onClick={() => setPromptAction(item.id)}
+                            >
+                                {tString(language, 'open_in', item.label)}
+                            </DropdownMenuItem>
+                        ))}
+                    </DropdownMenu>
+                </ButtonGroup>
+            ) : (
+                mainButton
+            )}
+        </div>
+    );
+}
+
+/**
+ * The agents on offer, overlapped into a stack, so the menu advertises what it holds without
+ * spelling out three names next to a button that already has one.
+ */
+function AgentIconStack() {
+    return (
+        <span className="flex items-center">
+            {AI_AGENTS.map((agent, index) => (
+                <span
+                    key={agent.id}
+                    className={tcls(
+                        'flex size-4 shrink-0 items-center justify-center rounded-full border border-tint bg-tint-base',
+                        // Each chip's border cuts into the one behind it, so the marks stay legible
+                        // however tightly they are stacked.
+                        index > 0 && '-ms-1.5'
+                    )}
+                >
+                    <Icon icon={agent.icon} className="size-2.5" />
+                </span>
+            ))}
+        </span>
+    );
+}
diff --git a/packages/gitbook/src/components/DocumentView/Prompt/PromptClient.tsx b/packages/gitbook/src/components/DocumentView/Prompt/PromptClient.tsx
index fa130041a..6bca4f152 100644
--- a/packages/gitbook/src/components/DocumentView/Prompt/PromptClient.tsx
+++ b/packages/gitbook/src/components/DocumentView/Prompt/PromptClient.tsx
@@ -5,14 +5,11 @@ import React from 'react';
 import type { DocumentBlockPrompt } from '@gitbook/api';
 import { Icon, type IconName } from '@gitbook/icons';
 
-import { Button, DropdownMenu, DropdownMenuItem, ToggleChevron } from '@/components/primitives';
-import { getURLForLLM } from '@/components/utils';
+import { PromptActions } from './PromptActions';
+import { ToggleChevron } from '@/components/primitives';
 import { tString, useLanguage } from '@/intl/client';
 import { tcls } from '@/lib/tailwind';
 
-const OPEN_IN_AI_PROVIDERS = ['claude', 'chatgpt', 'cursor'] as const;
-type AIProviders = (typeof OPEN_IN_AI_PROVIDERS)[number];
-
 type PromptClientProps = DocumentBlockPrompt['data'] & {
     contentIcon: IconName | null;
     prompt: string;
@@ -88,106 +85,3 @@ export function PromptClient(props: PromptClientProps) {
         </div>
     );
 }
-
-function PromptActions(props: { prompt: string; openInAIProviders: boolean }) {
-    const { prompt, openInAIProviders } = props;
-
-    return (
-        <div className="relative z-20 flex shrink-0 items-center gap-2">
-            <CopyPromptButton prompt={prompt} />
-            {openInAIProviders ? <OpenPromptDropdown prompt={prompt} /> : null}
-        </div>
-    );
-}
-
-// time in milliseconds to show the "Copied" message after copying a prompt
-const COPIED_MESSAGE_DURATION = 1000;
-
-function CopyPromptButton(props: { prompt: string }) {
-    const { prompt } = props;
-    const language = useLanguage();
-    const [copied, setCopied] = React.useState(false);
-
-    React.useEffect(() => {
-        if (!copied) {
-            return;
-        }
-
-        const timeout = setTimeout(() => {
-            setCopied(false);
-        }, COPIED_MESSAGE_DURATION);
-
-        return () => {
-            clearTimeout(timeout);
-        };
-    }, [copied]);
-
-    return (
-        <Button
-            variant="primary"
-            size="xsmall"
-            label={copied ? tString(language, 'code_copied') : tString(language, 'prompt_copy')}
-            disabled={!prompt}
-            onClick={() => {
-                navigator.clipboard.writeText(prompt);
-                setCopied(true);
-            }}
-        />
-    );
-}
-
-function OpenPromptDropdown(props: { prompt: string }) {
-    const { prompt } = props;
-    const language = useLanguage();
-
-    return (
-        <DropdownMenu
-            align="end"
-            className="!min-w-48 max-w-max"
-            button={
-                <Button
-                    label={tString(language, 'open_in_ai')}
-                    trailing={<ToggleChevron className="size-text-sm" />}
-                    size="xsmall"
-                    variant="secondary"
-                    className="max-sm:hidden"
-                    disabled={!prompt}
-                />
-            }
-        >
-            {OPEN_IN_AI_PROVIDERS.map((provider) => {
-                const definition = getPromptOpenActionDefinition(provider);
-                return (
-                    <DropdownMenuItem
-                        key={provider}
-                        href={getURLForLLM(provider, prompt)}
-                        target="_blank"
-                        leadingIcon={definition.icon}
-                    >
-                        {tString(language, 'open_in', definition.label)}
-                    </DropdownMenuItem>
-                );
-            })}
-        </DropdownMenu>
-    );
-}
-
-function getPromptOpenActionDefinition(action: AIProviders): { icon: IconName; label: string } {
-    switch (action) {
-        case 'cursor':
-            return {
-                icon: 'cursor',
-                label: 'Cursor',
-            };
-        case 'claude':
-            return {
-                icon: 'claude',
-                label: 'Claude',
-            };
-        case 'chatgpt':
-            return {
-                icon: 'chatgpt',
-                label: 'ChatGPT',
-            };
-    }
-}
diff --git a/packages/gitbook/src/components/DocumentView/Prompt/promptAction.ts b/packages/gitbook/src/components/DocumentView/Prompt/promptAction.ts
new file mode 100644
index 000000000..ad737d8c1
--- /dev/null
+++ b/packages/gitbook/src/components/DocumentView/Prompt/promptAction.ts
@@ -0,0 +1,95 @@
+'use client';
+
+import React from 'react';
+
+import { type AIAgentId, isAIAgentId } from '@/lib/ai-agents';
+import { getLocalStorageItem, setLocalStorageItem } from '@/lib/browser';
+
+/**
+ * What a prompt block does when its main button is pressed: copy the prompt, or hand it to one of
+ * the coding agents.
+ */
+export type PromptActionId = 'copy' | AIAgentId;
+
+/**
+ * Not namespaced per site: a visitor who works in Cursor works in Cursor everywhere, so the pick
+ * follows them across sites the same way the `select` store's slugs do.
+ */
+const STORAGE_KEY = '@gitbook/prompt-action';
+
+const DEFAULT_ACTION: PromptActionId = 'copy';
+
+let state: PromptActionId = DEFAULT_ACTION;
+let loaded = false;
+const listeners = new Set<() => void>();
+
+function isPromptActionId(value: unknown): value is PromptActionId {
+    return value === 'copy' || isAIAgentId(value);
+}
+
+function read(): PromptActionId {
+    const stored = getLocalStorageItem<unknown>(STORAGE_KEY, DEFAULT_ACTION);
+    return isPromptActionId(stored) ? stored : DEFAULT_ACTION;
+}
+
+function emitChange() {
+    for (const listener of listeners) {
+        listener();
+    }
+}
+
+/**
+ * Adopt what's in storage, once per page load. Deferred to the first subscription rather than run at
+ * module scope so the first client render still matches the server's, and the stored pick only
+ * lands once React is listening.
+ */
+function load() {
+    if (loaded || typeof window === 'undefined') {
+        return;
+    }
+    loaded = true;
+    state = read();
+
+    // Another tab picking an action updates this one too.
+    window.addEventListener('storage', (event) => {
+        if (event.key !== null && event.key !== STORAGE_KEY) {
+            return;
+        }
+        state = read();
+        emitChange();
+    });
+}
+
+function subscribe(listener: () => void) {
+    load();
+    listeners.add(listener);
+    // Storage was only read just now, so nudge the subscriber to re-read the snapshot.
+    listener();
+    return () => {
+        listeners.delete(listener);
+    };
+}
+
+/**
+ * Remember the action the visitor picked, for every prompt block on the page and the next one.
+ */
+export function setPromptAction(action: PromptActionId) {
+    load();
+    if (state === action) {
+        return;
+    }
+    state = action;
+    setLocalStorageItem(STORAGE_KEY, action);
+    emitChange();
+}
+
+/**
+ * The action the visitor last picked, defaulting to copying the prompt.
+ */
+export function usePromptAction(): PromptActionId {
+    return React.useSyncExternalStore(
+        subscribe,
+        () => state,
+        () => DEFAULT_ACTION
+    );
+}
diff --git a/packages/gitbook/src/components/utils/getURLForLLM.ts b/packages/gitbook/src/components/utils/getURLForLLM.ts
index 0eb72479b..0fd4c9b8f 100644
--- a/packages/gitbook/src/components/utils/getURLForLLM.ts
+++ b/packages/gitbook/src/components/utils/getURLForLLM.ts
@@ -3,15 +3,13 @@ import assertNever from 'assert-never';
 /**
  * Returns the URL to open the page in a LLM with a pre-filled prompt.
  */
-export function getURLForLLM(provider: 'chatgpt' | 'claude' | 'cursor', prompt: string) {
+export function getURLForLLM(provider: 'chatgpt' | 'claude', prompt: string) {
     const encodedPrompt = encodeURIComponent(prompt);
     switch (provider) {
         case 'chatgpt':
             return `https://chat.openai.com/?q=${encodedPrompt}`;
         case 'claude':
             return `https://claude.ai/new?q=${encodedPrompt}`;
-        case 'cursor':
-            return `https://cursor.com/link/prompt?text=${encodedPrompt}`;
         default:
             assertNever(provider);
     }
diff --git a/packages/gitbook/src/lib/ai-agents.test.ts b/packages/gitbook/src/lib/ai-agents.test.ts
new file mode 100644
index 000000000..c91e73086
--- /dev/null
+++ b/packages/gitbook/src/lib/ai-agents.test.ts
@@ -0,0 +1,48 @@
+import { describe, expect, it } from 'bun:test';
+
+import { AI_AGENTS, getAIAgent, isAIAgentId } from './ai-agents';
+
+describe('AI_AGENTS', () => {
+    it('builds a deep link for each agent', () => {
+        expect(AI_AGENTS.map((agent) => agent.getURL('hello'))).toEqual([
+            'claude://code/new?q=hello',
+            'codex://new?prompt=hello',
+            'cursor://anysphere.cursor-deeplink/prompt?text=hello',
+        ]);
+    });
+
+    it('encodes prompts so their content never leaks into the query string', () => {
+        const prompt = 'Fix the bug in a/b.ts?\n#1 & be nice';
+
+        for (const agent of AI_AGENTS) {
+            const url = agent.getURL(prompt);
+            // Everything past the single `=` is the encoded prompt, so the separators a prompt can
+            // contain (`?`, `#`, `&`, newlines) can't be read as URL syntax.
+            const [prefix, ...rest] = url.split('=');
+            expect(rest).toHaveLength(1);
+            expect(prefix).not.toContain(' ');
+            expect(decodeURIComponent(rest.join(''))).toBe(prompt);
+        }
+    });
+});
+
+describe('isAIAgentId', () => {
+    it('accepts known agents', () => {
+        expect(isAIAgentId('claude')).toBe(true);
+        expect(isAIAgentId('codex')).toBe(true);
+        expect(isAIAgentId('cursor')).toBe(true);
+    });
+
+    it('rejects anything else', () => {
+        expect(isAIAgentId('copy')).toBe(false);
+        expect(isAIAgentId('chatgpt')).toBe(false);
+        expect(isAIAgentId(undefined)).toBe(false);
+        expect(isAIAgentId({ id: 'claude' })).toBe(false);
+    });
+});
+
+describe('getAIAgent', () => {
+    it('returns the agent for a known id', () => {
+        expect(getAIAgent('cursor').label).toBe('Cursor');
+    });
+});
diff --git a/packages/gitbook/src/lib/ai-agents.ts b/packages/gitbook/src/lib/ai-agents.ts
new file mode 100644
index 000000000..63d94e706
--- /dev/null
+++ b/packages/gitbook/src/lib/ai-agents.ts
@@ -0,0 +1,70 @@
+import type { IconName } from '@gitbook/icons';
+
+/**
+ * A coding agent a prompt can be handed to.
+ */
+export interface AIAgent {
+    id: string;
+    label: string;
+    icon: IconName;
+    /** The agent's deep link, opening it with the prompt typed in but not sent. */
+    getURL: (prompt: string) => string;
+}
+
+/**
+ * Coding agents a prompt can be handed to, in the order menus offer them.
+ *
+ * Each link opens the agent installed on the visitor's machine, so the prompt never leaves their
+ * computer. Each also caps how much it carries — around 14,000 characters for Claude, 8,000 for
+ * Cursor.
+ *
+ * Claude Code's own `claude-cli://` scheme is deliberately absent: on macOS it launches by having
+ * AppleScript *type* its command into a terminal, where the tty cuts the line at 1,024 bytes and
+ * silently truncates the prompt. `claude://code/new` opens the same session inside the desktop app,
+ * with no terminal in between.
+ */
+export const AI_AGENTS = [
+    {
+        id: 'claude',
+        label: 'Claude',
+        icon: 'claude',
+        // https://support.claude.com/en/articles/14729294-open-claude-desktop-with-a-link
+        getURL: (prompt: string) => `claude://code/new?q=${encodeURIComponent(prompt)}`,
+    },
+    {
+        id: 'codex',
+        label: 'Codex',
+        // No Codex icon in the library; the OpenAI mark it shares with ChatGPT stands in, as it
+        // already does for the Codex MCP page action.
+        icon: 'chatgpt',
+        getURL: (prompt: string) => `codex://new?prompt=${encodeURIComponent(prompt)}`,
+    },
+    {
+        id: 'cursor',
+        label: 'Cursor',
+        icon: 'cursor',
+        // https://cursor.com/docs/integrations/deeplinks
+        getURL: (prompt: string) =>
+            `cursor://anysphere.cursor-deeplink/prompt?text=${encodeURIComponent(prompt)}`,
+    },
+] as const satisfies readonly AIAgent[];
+
+export type AIAgentId = (typeof AI_AGENTS)[number]['id'];
+
+/**
+ * Find an agent by its identifier.
+ */
+export function getAIAgent(id: AIAgentId): (typeof AI_AGENTS)[number] {
+    const agent = AI_AGENTS.find((agent) => agent.id === id);
+    if (!agent) {
+        throw new Error(`Unknown AI agent: ${id}`);
+    }
+    return agent;
+}
+
+/**
+ * Check that a value is a known agent identifier, to validate persisted or external input.
+ */
+export function isAIAgentId(value: unknown): value is AIAgentId {
+    return AI_AGENTS.some((agent) => agent.id === value);
+}