fix: resolve npm CLI wrappers in Windows watchers

lib/provider-detection.js

@@ -2,13 +2,17 @@ const { execSync, spawnSync } = require('child_process');
 const fs = require('fs');
 const path = require('path');
 
+function commandLookupCommand(command) {
+  return process.platform === 'win32' ? `where ${command}` : `command -v ${command}`;
+}
+
 function commandExists(command) {
   if (!command) return false;
   if (command.includes(path.sep)) {
     return fs.existsSync(command);
   }
   try {
-    execSync(`command -v ${command}`, { stdio: 'pipe' });
+    execSync(commandLookupCommand(command), { stdio: 'pipe' });
     return true;
   } catch {
     return false;
@@ -21,8 +25,8 @@ function getCommandPath(command) {
     return fs.existsSync(command) ? command : null;
   }
   try {
-    const output = execSync(`command -v ${command}`, { encoding: 'utf8', stdio: 'pipe' });
-    return output.trim() || null;
+    const output = execSync(commandLookupCommand(command), { encoding: 'utf8', stdio: 'pipe' });
+    return output.trim().split(/\r?\n/)[0] || null;
   } catch {
     return null;
   }
@@ -32,7 +36,7 @@ function getHelpOutput(command, args = []) {
   if (!commandExists(command)) return '';
 
   const attempt = (flag) => {
-    const result = spawnSync(command, [...args, flag], { encoding: 'utf8' });
+    const result = spawnCommandSync(command, [...args, flag]);
     const output = `${result.stdout || ''}${result.stderr || ''}`;
     return output.trim();
   };
@@ -46,14 +50,57 @@ function getHelpOutput(command, args = []) {
 
 function getVersionOutput(command, args = []) {
   if (!commandExists(command)) return '';
-  const result = spawnSync(command, [...args, '--version'], { encoding: 'utf8' });
+  const result = spawnCommandSync(command, [...args, '--version']);
   const output = `${result.stdout || ''}${result.stderr || ''}`;
   return output.trim();
 }
 
+function spawnCommandSync(command, args = []) {
+  const spawnSpec = resolveWindowsCommandSpawn(command, args);
+  return spawnSync(spawnSpec.command, spawnSpec.args, { encoding: 'utf8' });
+}
+
+function resolveWindowsCommandSpawn(command, args = []) {
+  if (process.platform !== 'win32') {
+    return { command, args: [...args] };
+  }
+
+  const resolvedCommand = getCommandPath(command) || command;
+  if (!/\.(cmd|bat)$/i.test(resolvedCommand)) {
+    return { command: resolvedCommand, args: [...args] };
+  }
+
+  const wrapperContent = fs.readFileSync(resolvedCommand, 'utf8');
+  const scriptPath = extractNodeScriptFromCmdWrapper(wrapperContent, resolvedCommand);
+
+  if (!scriptPath) {
+    return { command: resolvedCommand, args: [...args] };
+  }
+
+  return {
+    command: process.execPath,
+    args: [scriptPath, ...args],
+  };
+}
+
+function extractNodeScriptFromCmdWrapper(wrapperContent, wrapperPath) {
+  const normalized = wrapperContent.replace(/\r\n/g, '\n');
+  const match = normalized.match(/"%~dp0\\([^"\n]+\.(?:js|cjs|mjs))"/i);
+  if (!match) {
+    return null;
+  }
+
+  const relativeScriptPath = match[1].replace(/\\/g, path.sep);
+  return path.resolve(path.dirname(wrapperPath), relativeScriptPath);
+}
+
 module.exports = {
   commandExists,
   getCommandPath,
   getHelpOutput,
   getVersionOutput,
+  commandLookupCommand,
+  resolveWindowsCommandSpawn,
+  extractNodeScriptFromCmdWrapper,
+  spawnCommandSync,
 };

task-lib/attachable-watcher.js

@@ -68,6 +68,7 @@ process.on('unhandledRejection', (reason) => {
 const require = createRequire(import.meta.url);
 const { AttachServer } = require('../src/attach');
 const { normalizeProviderName } = require('../lib/provider-names');
+const { resolveWindowsCommandSpawn } = require('../lib/provider-detection');
 
 const taskId = taskIdArg;
 const cwd = cwdArg;
@@ -91,8 +92,9 @@ const providerName = normalizeProviderName(config.provider || 'claude');
 const enableRecovery = providerName === 'claude';
 
 const env = { ...process.env, ...(config.env || {}) };
-const command = config.command || 'claude';
 const finalArgs = [...args];
+const spawnSpec = resolveWindowsCommandSpawn(config.command || 'claude', finalArgs);
+const command = spawnSpec.command;
 
 const silentJsonMode =
   config.outputFormat === 'json' && config.jsonSchema && config.silentJsonOutput && enableRecovery;
@@ -241,7 +243,7 @@ server = new AttachServer({
   id: taskId,
   socketPath,
   command,
-  args: finalArgs,
+  args: spawnSpec.args,
   cwd,
   env,
   cols: 120,

task-lib/runner.js

@@ -9,6 +9,7 @@ const require = createRequire(import.meta.url);
 const { loadSettings } = require('../lib/settings.js');
 const { normalizeProviderName } = require('../lib/provider-names');
 const { getProvider } = require('../src/providers');
+const { getCommandPath } = require('../lib/provider-detection');
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 
@@ -156,7 +157,7 @@ function buildWatcherConfig(outputFormat, jsonSchema, options, providerName, com
     jsonSchema,
     silentJsonOutput: options.silentJsonOutput || false,
     provider: providerName,
-    command: commandSpec.binary,
+    command: getCommandPath(commandSpec.binary) || commandSpec.binary,
     env: commandSpec.env || {},
   };
 }

task-lib/watcher.js

@@ -17,6 +17,7 @@ import { createRequire } from 'module';
 
 const require = createRequire(import.meta.url);
 const { normalizeProviderName } = require('../lib/provider-names');
+const { resolveWindowsCommandSpawn } = require('../lib/provider-detection');
 
 const [, , taskId, cwd, logFile, argsJson, configJson] = process.argv;
 const args = JSON.parse(argsJson);
@@ -30,10 +31,10 @@ const providerName = normalizeProviderName(config.provider || 'claude');
 const enableRecovery = providerName === 'claude';
 
 const env = { ...process.env, ...(config.env || {}) };
-const command = config.command || 'claude';
 const finalArgs = [...args];
-
-const child = spawn(command, finalArgs, {
+const spawnSpec = resolveWindowsCommandSpawn(config.command || 'claude', finalArgs);
+const command = spawnSpec.command;
+const child = spawn(command, spawnSpec.args, {
   cwd,
   env,
   stdio: ['ignore', 'pipe', 'pipe'],

tests/providers/detection.test.js

@@ -1,9 +1,17 @@
 const assert = require('assert');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const sinon = require('sinon');
 const {
   commandExists,
   getCommandPath,
   getHelpOutput,
   getVersionOutput,
+  commandLookupCommand,
+  resolveWindowsCommandSpawn,
+  extractNodeScriptFromCmdWrapper,
+  spawnCommandSync,
 } = require('../../lib/provider-detection');
 
 describe('Provider CLI detection', () => {
@@ -28,3 +36,104 @@ describe('Provider CLI detection', () => {
     assert.ok(version.length > 0);
   });
 });
+
+describe('commandLookupCommand', () => {
+  let platformStub;
+
+  afterEach(() => {
+    if (platformStub) platformStub.restore();
+  });
+
+  it('uses where on Windows', () => {
+    platformStub = sinon.stub(process, 'platform').value('win32');
+    assert.strictEqual(commandLookupCommand('claude'), 'where claude');
+  });
+
+  it('uses command -v on non-Windows platforms', () => {
+    platformStub = sinon.stub(process, 'platform').value('linux');
+    assert.strictEqual(commandLookupCommand('claude'), 'command -v claude');
+  });
+});
+
+describe('extractNodeScriptFromCmdWrapper', () => {
+  it('extracts the node entry script from an npm cmd wrapper', () => {
+    const wrapperPath = 'C:\\Users\\sense\\AppData\\Roaming\\npm\\claude.cmd';
+    const wrapper = `@ECHO off\r\n"%~dp0\\node.exe"  "%~dp0\\node_modules\\@anthropic-ai\\claude-code\\cli.js" %*\r\n`;
+
+    const scriptPath = extractNodeScriptFromCmdWrapper(wrapper, wrapperPath);
+    assert.strictEqual(
+      scriptPath,
+      path.resolve(path.dirname(wrapperPath), 'node_modules/@anthropic-ai/claude-code/cli.js')
+    );
+  });
+
+  it('returns null when the wrapper does not reference a node script', () => {
+    const wrapper = '@ECHO off\r\necho hello\r\n';
+    assert.strictEqual(extractNodeScriptFromCmdWrapper(wrapper, 'C:\\tmp\\tool.cmd'), null);
+  });
+});
+
+describe('resolveWindowsCommandSpawn', () => {
+  let platformStub;
+  let tempDir;
+
+  afterEach(() => {
+    sinon.restore();
+    platformStub = null;
+    if (tempDir) {
+      fs.rmSync(tempDir, { recursive: true, force: true });
+      tempDir = null;
+    }
+  });
+
+  it('invokes node directly for npm cmd wrappers on Windows', () => {
+    platformStub = sinon.stub(process, 'platform').value('win32');
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'provider-detection-'));
+    const wrapperPath = path.join(tempDir, 'claude.cmd');
+    const scriptRel = 'node_modules\\@anthropic-ai\\claude-code\\cli.js';
+    fs.writeFileSync(
+      wrapperPath,
+      `@ECHO off\r\n"%~dp0\\node.exe"  "%~dp0\\${scriptRel}" %*\r\n`
+    );
+
+    const spec = resolveWindowsCommandSpawn(wrapperPath, ['--print', 'hello world']);
+    assert.strictEqual(spec.command, process.execPath);
+    assert.strictEqual(
+      spec.args[0],
+      path.resolve(tempDir, 'node_modules/@anthropic-ai/claude-code/cli.js')
+    );
+    assert.deepStrictEqual(spec.args.slice(1), ['--print', 'hello world']);
+  });
+
+  it('returns the original command on non-Windows platforms', () => {
+    platformStub = sinon.stub(process, 'platform').value('linux');
+    const spec = resolveWindowsCommandSpawn('claude', ['--print', 'hello']);
+    assert.strictEqual(spec.command, 'claude');
+    assert.deepStrictEqual(spec.args, ['--print', 'hello']);
+  });
+
+  it('uses the resolved spawn spec for sync help/version probes', () => {
+    platformStub = sinon.stub(process, 'platform').value('win32');
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'provider-detection-'));
+    const wrapperPath = path.join(tempDir, 'codex.cmd');
+    const scriptDir = path.join(tempDir, 'node_modules', '@openai', 'codex', 'dist');
+    fs.mkdirSync(scriptDir, { recursive: true });
+    const scriptPath = path.join(scriptDir, 'cli.js');
+    fs.writeFileSync(
+      scriptPath,
+      "if (process.argv.includes('--help')) { console.log('wrapped-help'); } else if (process.argv.includes('--version')) { console.log('wrapped-version'); }"
+    );
+    fs.writeFileSync(
+      wrapperPath,
+      '@ECHO off\r\n"%~dp0\\node.exe"  "%~dp0\\node_modules\\@openai\\codex\\dist\\cli.js" %*\r\n'
+    );
+
+    const help = getHelpOutput(wrapperPath, ['exec']);
+    const version = getVersionOutput(wrapperPath);
+    const result = spawnCommandSync(wrapperPath, ['exec', '--help']);
+
+    assert.strictEqual(help, 'wrapped-help');
+    assert.strictEqual(version, 'wrapped-version');
+    assert.strictEqual(result.stdout.trim(), 'wrapped-help');
+  });
+});