feat(engines): add session resuming support for ccr and cursor providers

add resumeSessionId option to command builders and runners
implement session ID capture and resume prompt handling
update stdin handling to support both new and resumed sessions

Author: moazbuilds

bun.lock

@@ -35,6 +35,7 @@
       "optionalDependencies": {
         "codemachine-darwin-arm64": "0.8.0",
         "codemachine-darwin-x64": "0.8.0",
+        "codemachine-linux-arm64": "0.8.0",
         "codemachine-linux-x64": "0.8.0",
         "codemachine-windows-x64": "0.8.0",
       },

src/infra/engines/providers/ccr/execution/commands.ts

@@ -1,6 +1,6 @@
 export interface CcrCommandOptions {
   workingDir: string;
-  prompt: string;
+  resumeSessionId?: string;
   model?: string;
 }
 
@@ -43,7 +43,7 @@ function mapModel(model?: string): string | undefined {
 }
 
 export function buildCcrExecCommand(options: CcrCommandOptions): CcrCommand {
-  const { model } = options;
+  const { resumeSessionId, model } = options;
 
   // Base args: --print for non-interactive mode, similar to Claude but using ccr code
   const args: string[] = [
@@ -57,14 +57,18 @@ export function buildCcrExecCommand(options: CcrCommandOptions): CcrCommand {
     'bypassPermissions',
   ];
 
+  // Add resume flag if resuming a session
+  if (resumeSessionId?.trim()) {
+    args.push('--resume', resumeSessionId.trim());
+  }
+
   // Add model if specified and valid
   const mappedModel = mapModel(model);
   if (mappedModel) {
     args.push('--model', mappedModel);
   }
 
-  // Prompt is now passed via stdin instead of as an argument
-  // Call ccr code - the runner passes cwd and prompt to spawnProcess
+  // Prompt is passed via stdin
   return {
     command: 'ccr',
     args,

src/infra/engines/providers/ccr/execution/runner.ts

@@ -12,10 +12,13 @@ import { formatThinking, formatCommand, formatResult } from '../../../../../shar
 export interface RunCcrOptions {
   prompt: string;
   workingDir: string;
+  resumeSessionId?: string;
+  resumePrompt?: string;
   model?: string;
   env?: NodeJS.ProcessEnv;
   onData?: (chunk: string) => void;
   onErrorData?: (chunk: string) => void;
+  onSessionId?: (sessionId: string) => void;
   abortSignal?: AbortSignal;
   timeout?: number; // Timeout in milliseconds (default: 1800000ms = 30 minutes)
 }
@@ -27,6 +30,20 @@ export interface RunCcrResult {
 
 const ANSI_ESCAPE_SEQUENCE = new RegExp(String.raw`\u001B\[[0-9;?]*[ -/]*[@-~]`, 'g');
 
+/**
+ * Build the final resume prompt combining steering instruction with user message
+ */
+function buildResumePrompt(userPrompt?: string): string {
+  const defaultPrompt = 'Continue from where you left off.';
+
+  if (!userPrompt) {
+    return defaultPrompt;
+  }
+
+  // Combine steering instruction with user's message
+  return `[USER STEERING] The user paused this session to give you new direction. Continue from where you left off, but prioritize the user's request: "${userPrompt}"`;
+}
+
 // Track tool names for associating with results
 const toolNameMap = new Map<string, string>();
 
@@ -105,7 +122,7 @@ function formatStreamJsonLine(line: string): string | null {
 }
 
 export async function runCcr(options: RunCcrOptions): Promise<RunCcrResult> {
-  const { prompt, workingDir, model, env, onData, onErrorData, abortSignal, timeout = 1800000 } = options;
+  const { prompt, workingDir, resumeSessionId, resumePrompt, model, env, onData, onErrorData, onSessionId, abortSignal, timeout = 1800000 } = options;
 
   if (!prompt) {
     throw new Error('runCcr requires a prompt.');
@@ -153,7 +170,7 @@ export async function runCcr(options: RunCcrOptions): Promise<RunCcrResult> {
     return result;
   };
 
-  const { command, args } = buildCcrExecCommand({ workingDir, prompt, model });
+  const { command, args } = buildCcrExecCommand({ workingDir, resumeSessionId, model });
 
   logger.debug(`CCR runner - prompt length: ${prompt.length}, lines: ${prompt.split('\n').length}`);
   logger.debug(`CCR runner - args count: ${args.length}, model: ${model ?? 'default'}`);
@@ -163,6 +180,7 @@ export async function runCcr(options: RunCcrOptions): Promise<RunCcrResult> {
 
   // Track JSON error events (CCR may exit 0 even on errors)
   let capturedError: string | null = null;
+  let sessionIdCaptured = false;
 
   let result;
   try {
@@ -171,7 +189,7 @@ export async function runCcr(options: RunCcrOptions): Promise<RunCcrResult> {
       args,
       cwd: workingDir,
       env: mergedEnv,
-      stdinInput: prompt, // Pass prompt via stdin instead of command-line argument
+      stdinInput: resumeSessionId ? buildResumePrompt(resumePrompt) : prompt,
       onStdout: inheritTTY
         ? undefined
         : (chunk) => {
@@ -188,6 +206,13 @@ export async function runCcr(options: RunCcrOptions): Promise<RunCcrResult> {
               // Check for error events (CCR may exit 0 even on errors like invalid model)
               try {
                 const json = JSON.parse(line);
+
+                // Capture session ID from first event that contains it
+                if (!sessionIdCaptured && json.session_id && onSessionId) {
+                  sessionIdCaptured = true;
+                  onSessionId(json.session_id);
+                }
+
                 // Check for error in result type
                 if (json.type === 'result' && json.is_error && json.result && !capturedError) {
                   capturedError = json.result;

src/infra/engines/providers/cursor/execution/commands.ts

@@ -1,6 +1,6 @@
 export interface CursorCommandOptions {
   workingDir: string;
-  prompt: string;
+  resumeSessionId?: string;
   model?: string;
   cursorConfigDir?: string;
 }
@@ -49,7 +49,7 @@ function mapModel(model?: string): string | undefined {
 }
 
 export function buildCursorExecCommand(options: CursorCommandOptions): CursorCommand {
-  const { model, cursorConfigDir } = options;
+  const { resumeSessionId, model, cursorConfigDir } = options;
 
   // Base args: -p for print mode, --force, streaming JSON output
   const args: string[] = [
@@ -59,6 +59,11 @@ export function buildCursorExecCommand(options: CursorCommandOptions): CursorCom
     'stream-json',
   ];
 
+  // Add resume flag if resuming a session
+  if (resumeSessionId?.trim()) {
+    args.push(`--resume=${resumeSessionId.trim()}`);
+  }
+
   // Add model if specified and valid
   const mappedModel = mapModel(model);
   if (mappedModel) {
@@ -70,8 +75,7 @@ export function buildCursorExecCommand(options: CursorCommandOptions): CursorCom
     args.push(cursorConfigDir);
   }
 
-  // Prompt is now passed via stdin instead of as an argument
-  // Call cursor-agent directly - the runner passes cwd and prompt to spawnProcess
+  // Prompt is passed via stdin
   return {
     command: 'cursor-agent',
     args,

src/infra/engines/providers/cursor/execution/runner.ts

@@ -11,10 +11,13 @@ import { debug } from '../../../../../shared/logging/logger.js';
 export interface RunCursorOptions {
   prompt: string;
   workingDir: string;
+  resumeSessionId?: string;
+  resumePrompt?: string;
   model?: string;
   env?: NodeJS.ProcessEnv;
   onData?: (chunk: string) => void;
   onErrorData?: (chunk: string) => void;
+  onSessionId?: (sessionId: string) => void;
   abortSignal?: AbortSignal;
   timeout?: number; // Timeout in milliseconds (default: 1800000ms = 30 minutes)
 }
@@ -32,6 +35,20 @@ const toolNameMap = new Map<string, string>();
 // Track accumulated thinking text for delta updates
 let accumulatedThinking = '';
 
+/**
+ * Build the final resume prompt combining steering instruction with user message
+ */
+function buildResumePrompt(userPrompt?: string): string {
+  const defaultPrompt = 'Continue from where you left off.';
+
+  if (!userPrompt) {
+    return defaultPrompt;
+  }
+
+  // Combine steering instruction with user's message
+  return `[USER STEERING] The user paused this session to give you new direction. Continue from where you left off, but prioritize the user's request: "${userPrompt}"`;
+}
+
 /**
  * Formats a Cursor stream-json line for display
  */
@@ -137,7 +154,7 @@ function formatStreamJsonLine(line: string): string | null {
 }
 
 export async function runCursor(options: RunCursorOptions): Promise<RunCursorResult> {
-  const { prompt, workingDir, model, env, onData, onErrorData, abortSignal, timeout = 1800000 } = options;
+  const { prompt, workingDir, resumeSessionId, resumePrompt, model, env, onData, onErrorData, onSessionId, abortSignal, timeout = 1800000 } = options;
 
   if (!prompt) {
     throw new Error('runCursor requires a prompt.');
@@ -187,7 +204,7 @@ export async function runCursor(options: RunCursorOptions): Promise<RunCursorRes
 
   const { command, args } = buildCursorExecCommand({
     workingDir,
-    prompt,
+    resumeSessionId,
     model,
     cursorConfigDir
   });
@@ -196,14 +213,16 @@ export async function runCursor(options: RunCursorOptions): Promise<RunCursorRes
   debug(`Cursor runner - prompt length: ${prompt.length}, lines: ${prompt.split('\n').length}`);
   debug(`Cursor runner - args count: ${args.length}, model: ${model ?? 'auto'}`);
 
+  let sessionIdCaptured = false;
+
   let result;
   try {
     result = await spawnProcess({
       command,
       args,
       cwd: workingDir,
       env: mergedEnv,
-      stdinInput: prompt, // Pass prompt via stdin instead of command-line argument
+      stdinInput: resumeSessionId ? buildResumePrompt(resumePrompt) : prompt,
     onStdout: inheritTTY
       ? undefined
       : (chunk) => {
@@ -214,6 +233,17 @@ export async function runCursor(options: RunCursorOptions): Promise<RunCursorRes
           for (const line of lines) {
             if (!line.trim()) continue;
 
+            // Capture session ID from first event that contains it
+            try {
+              const json = JSON.parse(line);
+              if (!sessionIdCaptured && json.session_id && onSessionId) {
+                sessionIdCaptured = true;
+                onSessionId(json.session_id);
+              }
+            } catch {
+              // Ignore parse errors
+            }
+
             const formatted = formatStreamJsonLine(line);
             if (formatted) {
               onData?.(formatted + '\n');