fix(websearch): support Gemini positional prompt mode

docs/websearch.md

@@ -1,6 +1,6 @@
 # WebSearch Configuration Guide
 
-Last Updated: 2026-02-04
+Last Updated: 2026-02-26
 
 CCS provides automatic web search capability for all profiles, including third-party providers that cannot access Anthropic's native WebSearch API.
 
@@ -19,7 +19,7 @@ Third-party profiles (OAuth and API-based) cannot use Anthropic's WebSearch beca
 
 CCS solves this with a hybrid fallback approach:
 
-1. **Gemini CLI Transformer** (Primary) - Uses `gemini -p` with `google_web_search` tool
+1. **Gemini CLI Transformer** (Primary) - Uses positional Gemini prompt mode (with legacy `-p` fallback) and `google_web_search` tool
 2. **MCP Fallback Chain** (Secondary) - MCP-based web search servers
 
 ## Architecture
@@ -53,7 +53,7 @@ The **ultimate solution** for third-party WebSearch. Uses `gemini` CLI with OAut
 ### How It Works
 
 1. A PreToolUse hook intercepts WebSearch tool calls
-2. Executes `gemini -p` with explicit google_web_search instruction
+2. Executes `gemini "<prompt>"` (positional mode) with explicit google_web_search instruction
 3. Returns search results directly to Claude via the hook's deny reason
 4. Claude receives full search results and continues the conversation
 

lib/hooks/websearch-transformer.cjs

@@ -282,6 +282,61 @@ async function processHook() {
 /**
  * Execute search via Gemini CLI
  */
+function shouldRetryGeminiWithLegacyPrompt(errorMessage) {
+  const lowerError = (errorMessage || '').toLowerCase();
+
+  return (
+    lowerError.includes('unknown option') ||
+    lowerError.includes('unknown argument') ||
+    lowerError.includes('unrecognized option') ||
+    lowerError.includes('usage: gemini') ||
+    lowerError.includes('use --prompt') ||
+    lowerError.includes('using the --prompt option')
+  );
+}
+
+function runGeminiCommand(args, timeoutMs) {
+  const spawnResult = spawnSync('gemini', args, {
+    encoding: 'utf8',
+    timeout: timeoutMs,
+    maxBuffer: 1024 * 1024 * 2,
+    stdio: ['pipe', 'pipe', 'pipe'],
+    shell: isWindows,
+  });
+
+  if (spawnResult.error) {
+    if (spawnResult.error.code === 'ENOENT') {
+      return { success: false, error: 'Gemini CLI not installed' };
+    }
+    throw spawnResult.error;
+  }
+
+  if (spawnResult.status !== 0) {
+    const stderr = (spawnResult.stderr || '').trim();
+    return {
+      success: false,
+      error: stderr || `Gemini CLI exited with code ${spawnResult.status}`,
+    };
+  }
+
+  const result = (spawnResult.stdout || '').trim();
+
+  if (!result || result.length < MIN_VALID_RESPONSE_LENGTH) {
+    return { success: false, error: 'Empty or too short response from Gemini' };
+  }
+
+  const lowerResult = result.toLowerCase();
+  if (
+    lowerResult.includes('error:') ||
+    lowerResult.includes('failed to') ||
+    lowerResult.includes('authentication required')
+  ) {
+    return { success: false, error: `Gemini returned error: ${result.substring(0, 100)}` };
+  }
+
+  return { success: true, content: result };
+}
+
 function tryGeminiSearch(query, timeoutSec = DEFAULT_TIMEOUT_SEC) {
   try {
     const timeoutMs = timeoutSec * 1000;
@@ -290,54 +345,31 @@ function tryGeminiSearch(query, timeoutSec = DEFAULT_TIMEOUT_SEC) {
 
     // Allow model override via env var
     const model = process.env.CCS_WEBSEARCH_GEMINI_MODEL || config.model;
+    const baseArgs = ['--model', model, '--yolo'];
+    const positionalArgs = [...baseArgs, prompt];
 
     if (process.env.CCS_DEBUG) {
+      console.error(`[CCS Hook] Executing: gemini --model ${model} --yolo "..."`);
+    }
+
+    // Current Gemini CLI prefers positional prompts and deprecates -p/--prompt.
+    // Retry once with -p for legacy CLIs that still require it.
+    const positionalResult = runGeminiCommand(positionalArgs, timeoutMs);
+    if (positionalResult.success) {
+      return positionalResult;
+    }
+
+    if (!shouldRetryGeminiWithLegacyPrompt(positionalResult.error)) {
+      return positionalResult;
+    }
+
+    if (process.env.CCS_DEBUG) {
+      console.error('[CCS Hook] Positional Gemini prompt failed; retrying with -p for legacy CLI');
       console.error(`[CCS Hook] Executing: gemini --model ${model} --yolo -p "..."`);
     }
 
-    const spawnResult = spawnSync(
-      'gemini',
-      ['--model', model, '--yolo', '-p', prompt],
-      {
-        encoding: 'utf8',
-        timeout: timeoutMs,
-        maxBuffer: 1024 * 1024 * 2,
-        stdio: ['pipe', 'pipe', 'pipe'],
-        shell: isWindows,
-      }
-    );
-
-    if (spawnResult.error) {
-      if (spawnResult.error.code === 'ENOENT') {
-        return { success: false, error: 'Gemini CLI not installed' };
-      }
-      throw spawnResult.error;
-    }
-
-    if (spawnResult.status !== 0) {
-      const stderr = (spawnResult.stderr || '').trim();
-      return {
-        success: false,
-        error: stderr || `Gemini CLI exited with code ${spawnResult.status}`,
-      };
-    }
-
-    const result = (spawnResult.stdout || '').trim();
-
-    if (!result || result.length < MIN_VALID_RESPONSE_LENGTH) {
-      return { success: false, error: 'Empty or too short response from Gemini' };
-    }
-
-    const lowerResult = result.toLowerCase();
-    if (
-      lowerResult.includes('error:') ||
-      lowerResult.includes('failed to') ||
-      lowerResult.includes('authentication required')
-    ) {
-      return { success: false, error: `Gemini returned error: ${result.substring(0, 100)}` };
-    }
-
-    return { success: true, content: result };
+    const legacyPromptArgs = [...baseArgs, '-p', prompt];
+    return runGeminiCommand(legacyPromptArgs, timeoutMs);
   } catch (err) {
     if (err.killed) {
       return { success: false, error: 'Gemini CLI timed out' };
@@ -362,17 +394,13 @@ function tryOpenCodeSearch(query, timeoutSec = DEFAULT_TIMEOUT_SEC) {
       console.error(`[CCS Hook] Executing: opencode run --model ${model} "..."`);
     }
 
-    const spawnResult = spawnSync(
-      'opencode',
-      ['run', prompt, '--model', model],
-      {
-        encoding: 'utf8',
-        timeout: timeoutMs,
-        maxBuffer: 1024 * 1024 * 2,
-        stdio: ['pipe', 'pipe', 'pipe'],
-        shell: isWindows,
-      }
-    );
+    const spawnResult = spawnSync('opencode', ['run', prompt, '--model', model], {
+      encoding: 'utf8',
+      timeout: timeoutMs,
+      maxBuffer: 1024 * 1024 * 2,
+      stdio: ['pipe', 'pipe', 'pipe'],
+      shell: isWindows,
+    });
 
     if (spawnResult.error) {
       if (spawnResult.error.code === 'ENOENT') {
@@ -599,9 +627,7 @@ function outputNoToolsMessage(query) {
  * Output all providers failed message
  */
 function outputAllFailedMessage(query, errors) {
-  const errorDetails = errors
-    .map((e) => `  - ${e.provider}: ${e.error}`)
-    .join('\n');
+  const errorDetails = errors.map((e) => `  - ${e.provider}: ${e.error}`).join('\n');
 
   const message = [
     '[WebSearch - All Providers Failed]',