feat(cursor): wire /summarize and /clear slash builtins for remote sessions

Seed cursor builtins for web autocomplete, parse summarize/clear in
cursorRemoteLauncher (pass-through to agent -p; reject /clear with args).

Fixes tiann#738

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: heavygee

cli/src/cursor/cursorRemoteLauncher.ts

@@ -13,6 +13,7 @@ import {
 import type { CursorSession } from './session';
 import type { CursorStreamEvent } from './utils/cursorEventConverter';
 import { parseCursorEvent, convertCursorEventToAgentMessage } from './utils/cursorEventConverter';
+import { parseCursorSpecialCommand } from './cursorSpecialCommands';
 
 function buildAgentArgs(opts: {
     message: string;
@@ -97,10 +98,29 @@ class CursorRemoteLauncher extends RemoteLauncherBase {
             }
 
             const { message, mode } = batch;
+            const specialCommand = parseCursorSpecialCommand(message);
+
+            if (specialCommand.type === 'invalid') {
+                session.sendSessionEvent({ type: 'message', message: specialCommand.message });
+                messageBuffer.addMessage(specialCommand.message, 'status');
+                if (session.queue.size() === 0 && !this.shouldExit) {
+                    sendReady();
+                }
+                continue;
+            }
+
             const { mode: agentMode, yolo } = permissionModeToAgentArgs(mode.permissionMode as string);
             this.applyDisplayMode(mode.permissionMode as string);
             messageBuffer.addMessage(message, 'user');
 
+            if (specialCommand.type === 'summarize') {
+                logger.debug('[cursor-remote] /summarize — pass-through to agent -p');
+                messageBuffer.addMessage('Context summarization requested', 'status');
+            } else if (specialCommand.type === 'clear') {
+                logger.debug('[cursor-remote] /clear — pass-through to agent -p');
+                messageBuffer.addMessage('Context clear requested', 'status');
+            }
+
             const args = buildAgentArgs({
                 message,
                 cwd: session.path,

cli/src/cursor/cursorSpecialCommands.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, it } from 'vitest';
+import { parseCursorSpecialCommand } from './cursorSpecialCommands';
+
+describe('parseCursorSpecialCommand', () => {
+    it('accepts /summarize with optional instructions', () => {
+        expect(parseCursorSpecialCommand('/summarize')).toEqual({
+            type: 'summarize',
+            message: '/summarize'
+        });
+        expect(parseCursorSpecialCommand('  /summarize keep peer relocate recap  ')).toEqual({
+            type: 'summarize',
+            message: '/summarize keep peer relocate recap'
+        });
+    });
+
+    it('accepts exact /clear', () => {
+        expect(parseCursorSpecialCommand('  /clear  ')).toEqual({ type: 'clear' });
+    });
+
+    it('rejects /clear with arguments', () => {
+        expect(parseCursorSpecialCommand('/clear now')).toEqual({
+            type: 'invalid',
+            command: 'clear',
+            message: '/clear does not accept arguments'
+        });
+    });
+
+    it('ignores regular slash-like messages', () => {
+        expect(parseCursorSpecialCommand('/summarizer')).toEqual({ type: null });
+        expect(parseCursorSpecialCommand('please /summarize')).toEqual({ type: null });
+        expect(parseCursorSpecialCommand('/clearing')).toEqual({ type: null });
+    });
+});

cli/src/cursor/cursorSpecialCommands.ts

@@ -0,0 +1,32 @@
+export type CursorSpecialCommand =
+    | { type: 'summarize'; message: string }
+    | { type: 'clear' }
+    | { type: 'invalid'; command: 'clear'; message: string }
+    | { type: null };
+
+/**
+ * Parse Cursor-specific slash commands for remote sessions.
+ * Summarize accepts optional trailing instructions after the command.
+ * Messages are still passed verbatim to `agent -p` — this parser is for detection and UI contract only.
+ */
+export function parseCursorSpecialCommand(message: string): CursorSpecialCommand {
+    const trimmed = message.trim();
+
+    if (trimmed === '/summarize' || trimmed.startsWith('/summarize ')) {
+        return { type: 'summarize', message: trimmed };
+    }
+
+    if (trimmed === '/clear') {
+        return { type: 'clear' };
+    }
+
+    if (trimmed.startsWith('/clear ')) {
+        return {
+            type: 'invalid',
+            command: 'clear',
+            message: '/clear does not accept arguments'
+        };
+    }
+
+    return { type: null };
+}

shared/src/slashCommands.ts

@@ -39,7 +39,10 @@ export const BUILTIN_SLASH_COMMANDS = {
         { name: 'default', description: 'Return OpenCode permission mode to default', source: 'builtin' },
         { name: 'init', description: 'Generate or refresh AGENTS.md for this project', source: 'builtin' },
     ],
-    cursor: [],
+    cursor: [
+        { name: 'summarize', description: 'Summarize conversation context to free window space (pass-through to Cursor agent)', source: 'builtin' },
+        { name: 'clear', description: 'Clear conversation context if supported by Cursor agent', source: 'builtin' },
+    ],
 } as const satisfies Record<string, readonly SlashCommand[]>
 
 export function getBuiltinSlashCommands(agent: string): SlashCommand[] {

web/src/lib/codexSlashCommands.test.ts

@@ -19,6 +19,12 @@ describe('getBuiltinSlashCommands', () => {
             'permission',
         ]))
     })
+
+    it('exposes Cursor summarize and clear builtins', () => {
+        expect(getBuiltinSlashCommands('cursor').map((command) => command.name)).toEqual(
+            expect.arrayContaining(['summarize', 'clear'])
+        )
+    })
 })
 
 describe('mergeSlashCommands', () => {