feat(cli): add WebSocket-based network logging and streaming chunk support (#18383)

packages/cli/src/gemini.tsx

@@ -518,7 +518,7 @@ export async function main() {
 
     adminControlsListner.setConfig(config);
 
-    if (config.isInteractive() && config.storage && config.getDebugMode()) {
+    if (config.isInteractive() && config.getDebugMode()) {
       const { registerActivityLogger } = await import(
         './utils/activityLogger.js'
       );

packages/cli/src/nonInteractiveCli.test.ts

@@ -267,8 +267,8 @@ describe('runNonInteractive', () => {
     // so we no longer expect shutdownTelemetry to be called directly here
   });
 
-  it('should register activity logger when GEMINI_CLI_ACTIVITY_LOG_FILE is set', async () => {
-    vi.stubEnv('GEMINI_CLI_ACTIVITY_LOG_FILE', '/tmp/test.jsonl');
+  it('should register activity logger when GEMINI_CLI_ACTIVITY_LOG_TARGET is set', async () => {
+    vi.stubEnv('GEMINI_CLI_ACTIVITY_LOG_TARGET', '/tmp/test.jsonl');
     const events: ServerGeminiStreamEvent[] = [
       {
         type: GeminiEventType.Finished,
@@ -290,8 +290,8 @@ describe('runNonInteractive', () => {
     vi.unstubAllEnvs();
   });
 
-  it('should not register activity logger when GEMINI_CLI_ACTIVITY_LOG_FILE is not set', async () => {
-    vi.stubEnv('GEMINI_CLI_ACTIVITY_LOG_FILE', '');
+  it('should not register activity logger when GEMINI_CLI_ACTIVITY_LOG_TARGET is not set', async () => {
+    vi.stubEnv('GEMINI_CLI_ACTIVITY_LOG_TARGET', '');
     const events: ServerGeminiStreamEvent[] = [
       {
         type: GeminiEventType.Finished,

packages/cli/src/nonInteractiveCli.ts

@@ -71,7 +71,7 @@ export async function runNonInteractive({
       },
     });
 
-    if (config.storage && process.env['GEMINI_CLI_ACTIVITY_LOG_FILE']) {
+    if (process.env['GEMINI_CLI_ACTIVITY_LOG_TARGET']) {
       const { registerActivityLogger } = await import(
         './utils/activityLogger.js'
       );

packages/cli/src/utils/activityLogger.ts

@@ -16,8 +16,33 @@ import path from 'node:path';
 import { EventEmitter } from 'node:events';
 import { CoreEvent, coreEvents, debugLogger } from '@google/gemini-cli-core';
 import type { Config } from '@google/gemini-cli-core';
+import WebSocket from 'ws';
 
 const ACTIVITY_ID_HEADER = 'x-activity-request-id';
+const MAX_BUFFER_SIZE = 100;
+
+/**
+ * Parse a host:port string into its components.
+ * Uses the URL constructor for robust handling of IPv4, IPv6, and hostnames.
+ * Returns null for file paths or values without a valid port.
+ */
+function parseHostPort(value: string): { host: string; port: number } | null {
+  if (value.startsWith('/') || value.startsWith('.')) return null;
+
+  try {
+    const url = new URL(`ws://${value}`);
+    if (!url.port) return null;
+
+    const port = parseInt(url.port, 10);
+    if (url.hostname && !isNaN(port) && port > 0 && port <= 65535) {
+      return { host: url.hostname, port };
+    }
+  } catch {
+    // Not a valid host:port
+  }
+
+  return null;
+}
 
 export interface NetworkLog {
   id: string;
@@ -27,6 +52,11 @@ export interface NetworkLog {
   headers: Record<string, string>;
   body?: string;
   pending?: boolean;
+  chunk?: {
+    index: number;
+    data: string;
+    timestamp: number;
+  };
   response?: {
     status: number;
     headers: Record<string, string>;
@@ -44,6 +74,7 @@ export class ActivityLogger extends EventEmitter {
   private static instance: ActivityLogger;
   private isInterceptionEnabled = false;
   private requestStartTimes = new Map<string, number>();
+  private networkLoggingEnabled = false;
 
   static getInstance(): ActivityLogger {
     if (!ActivityLogger.instance) {
@@ -52,6 +83,19 @@ export class ActivityLogger extends EventEmitter {
     return ActivityLogger.instance;
   }
 
+  enableNetworkLogging() {
+    this.networkLoggingEnabled = true;
+    this.emit('network-logging-enabled');
+  }
+
+  disableNetworkLogging() {
+    this.networkLoggingEnabled = false;
+  }
+
+  isNetworkLoggingEnabled(): boolean {
+    return this.networkLoggingEnabled;
+  }
+
   private stringifyHeaders(headers: unknown): Record<string, string> {
     const result: Record<string, string> = {};
     if (!headers) return result;
@@ -127,7 +171,8 @@ export class ActivityLogger extends EventEmitter {
           : input instanceof URL
             ? input.toString()
             : (input as any).url;
-      if (url.includes('127.0.0.1')) return originalFetch(input, init);
+      if (url.includes('127.0.0.1') || url.includes('localhost'))
+        return originalFetch(input, init);
 
       const id = Math.random().toString(36).substring(7);
       const method = (init?.method || 'GET').toUpperCase();
@@ -159,32 +204,89 @@ export class ActivityLogger extends EventEmitter {
         const response = await originalFetch(input, newInit);
         const clonedRes = response.clone();
 
-        clonedRes
-          .text()
-          .then((text) => {
-            const startTime = this.requestStartTimes.get(id);
-            const durationMs = startTime ? Date.now() - startTime : 0;
-            this.requestStartTimes.delete(id);
+        // Stream chunks if body is available
+        if (clonedRes.body) {
+          const reader = clonedRes.body.getReader();
+          const decoder = new TextDecoder();
+          const chunks: string[] = [];
+          let chunkIndex = 0;
 
-            this.safeEmitNetwork({
-              id,
-              pending: false,
-              response: {
-                status: response.status,
-                headers: this.stringifyHeaders(response.headers),
-                body: text,
-                durationMs,
-              },
+          const readStream = async () => {
+            try {
+              while (true) {
+                const { done, value } = await reader.read();
+                if (done) break;
+
+                const chunkData = decoder.decode(value, { stream: true });
+                chunks.push(chunkData);
+
+                // Emit chunk update
+                this.safeEmitNetwork({
+                  id,
+                  pending: true,
+                  chunk: {
+                    index: chunkIndex++,
+                    data: chunkData,
+                    timestamp: Date.now(),
+                  },
+                });
+              }
+
+              // Final update with complete response
+              const startTime = this.requestStartTimes.get(id);
+              const durationMs = startTime ? Date.now() - startTime : 0;
+              this.requestStartTimes.delete(id);
+
+              this.safeEmitNetwork({
+                id,
+                pending: false,
+                response: {
+                  status: response.status,
+                  headers: this.stringifyHeaders(response.headers),
+                  body: chunks.join(''),
+                  durationMs,
+                },
+              });
+            } catch (err) {
+              const message = err instanceof Error ? err.message : String(err);
+              this.safeEmitNetwork({
+                id,
+                pending: false,
+                error: `Failed to read response body: ${message}`,
+              });
+            }
+          };
+
+          void readStream();
+        } else {
+          // Fallback for responses without body stream
+          clonedRes
+            .text()
+            .then((text) => {
+              const startTime = this.requestStartTimes.get(id);
+              const durationMs = startTime ? Date.now() - startTime : 0;
+              this.requestStartTimes.delete(id);
+
+              this.safeEmitNetwork({
+                id,
+                pending: false,
+                response: {
+                  status: response.status,
+                  headers: this.stringifyHeaders(response.headers),
+                  body: text,
+                  durationMs,
+                },
+              });
+            })
+            .catch((err) => {
+              const message = err instanceof Error ? err.message : String(err);
+              this.safeEmitNetwork({
+                id,
+                pending: false,
+                error: `Failed to read response body: ${message}`,
+              });
             });
-          })
-          .catch((err) => {
-            const message = err instanceof Error ? err.message : String(err);
-            this.safeEmitNetwork({
-              id,
-              pending: false,
-              error: `Failed to read response body: ${message}`,
-            });
-          });
+        }
 
         return response;
       } catch (err: unknown) {
@@ -209,7 +311,8 @@ export class ActivityLogger extends EventEmitter {
           : options.href ||
             `${protocol}//${options.hostname || options.host || 'localhost'}${options.path || '/'}`;
 
-      if (url.includes('127.0.0.1')) return originalFn.apply(http, args);
+      if (url.includes('127.0.0.1') || url.includes('localhost'))
+        return originalFn.apply(http, args);
 
       const headers =
         typeof options === 'object' && typeof options !== 'function'
@@ -263,9 +366,24 @@ export class ActivityLogger extends EventEmitter {
 
       req.on('response', (res: any) => {
         const responseChunks: Buffer[] = [];
-        res.on('data', (chunk: Buffer) =>
-          responseChunks.push(Buffer.from(chunk)),
-        );
+        let chunkIndex = 0;
+
+        res.on('data', (chunk: Buffer) => {
+          const chunkBuffer = Buffer.from(chunk);
+          responseChunks.push(chunkBuffer);
+
+          // Emit chunk update for streaming
+          self.safeEmitNetwork({
+            id,
+            pending: true,
+            chunk: {
+              index: chunkIndex++,
+              data: chunkBuffer.toString('utf8'),
+              timestamp: Date.now(),
+            },
+          });
+        });
+
         res.on('end', () => {
           const buffer = Buffer.concat(responseChunks);
           const encoding = res.headers['content-encoding'];
@@ -323,53 +441,245 @@ export class ActivityLogger extends EventEmitter {
 }
 
 /**
- * Registers the activity logger.
- * Captures network and console logs to a session-specific JSONL file.
+ * Setup file-based logging to JSONL
+ */
+function setupFileLogging(
+  capture: ActivityLogger,
+  config: Config,
+  customPath?: string,
+) {
+  const logFile =
+    customPath ||
+    (config.storage
+      ? path.join(
+          config.storage.getProjectTempLogsDir(),
+          `session-${config.getSessionId()}.jsonl`,
+        )
+      : null);
+
+  if (!logFile) return;
+
+  const logsDir = path.dirname(logFile);
+  if (!fs.existsSync(logsDir)) {
+    fs.mkdirSync(logsDir, { recursive: true });
+  }
+
+  const writeToLog = (type: 'console' | 'network', payload: unknown) => {
+    try {
+      const entry =
+        JSON.stringify({
+          type,
+          payload,
+          sessionId: config.getSessionId(),
+          timestamp: Date.now(),
+        }) + '\n';
+
+      fs.promises.appendFile(logFile, entry).catch((err) => {
+        debugLogger.error('Failed to write to activity log:', err);
+      });
+    } catch (err) {
+      debugLogger.error('Failed to prepare activity log entry:', err);
+    }
+  };
+
+  capture.on('console', (payload) => writeToLog('console', payload));
+  capture.on('network', (payload) => writeToLog('network', payload));
+}
+
+/**
+ * Setup network-based logging via WebSocket
+ */
+function setupNetworkLogging(
+  capture: ActivityLogger,
+  host: string,
+  port: number,
+  config: Config,
+) {
+  const buffer: Array<Record<string, unknown>> = [];
+  let ws: WebSocket | null = null;
+  let reconnectTimer: NodeJS.Timeout | null = null;
+  let sessionId: string | null = null;
+  let pingInterval: NodeJS.Timeout | null = null;
+
+  const connect = () => {
+    try {
+      ws = new WebSocket(`ws://${host}:${port}/ws`);
+
+      ws.on('open', () => {
+        debugLogger.debug(`WebSocket connected to ${host}:${port}`);
+        // Register with CLI's session ID
+        sendMessage({
+          type: 'register',
+          sessionId: config.getSessionId(),
+          timestamp: Date.now(),
+        });
+      });
+
+      ws.on('message', (data: Buffer) => {
+        try {
+          const message = JSON.parse(data.toString());
+          handleServerMessage(message);
+        } catch (err) {
+          debugLogger.debug('Invalid WebSocket message:', err);
+        }
+      });
+
+      ws.on('close', () => {
+        debugLogger.debug(`WebSocket disconnected from ${host}:${port}`);
+        cleanup();
+        scheduleReconnect();
+      });
+
+      ws.on('error', (err) => {
+        debugLogger.debug(`WebSocket error:`, err);
+      });
+    } catch (err) {
+      debugLogger.debug(`Failed to connect WebSocket:`, err);
+      scheduleReconnect();
+    }
+  };
+
+  const handleServerMessage = (message: any) => {
+    switch (message.type) {
+      case 'registered':
+        sessionId = message.sessionId;
+        debugLogger.debug(`WebSocket session registered: ${sessionId}`);
+
+        // Start ping interval
+        if (pingInterval) clearInterval(pingInterval);
+        pingInterval = setInterval(() => {
+          sendMessage({ type: 'pong', timestamp: Date.now() });
+        }, 15000);
+
+        // Flush buffered logs
+        flushBuffer();
+        break;
+
+      case 'ping':
+        sendMessage({ type: 'pong', timestamp: Date.now() });
+        break;
+
+      default:
+        // Ignore unknown message types
+        break;
+    }
+  };
+
+  const sendMessage = (message: any) => {
+    if (ws && ws.readyState === WebSocket.OPEN) {
+      ws.send(JSON.stringify(message));
+    }
+  };
+
+  const sendToNetwork = (type: 'console' | 'network', payload: unknown) => {
+    const message = {
+      type,
+      payload,
+      sessionId: sessionId || config.getSessionId(),
+      timestamp: Date.now(),
+    };
+
+    // If not connected or network logging not enabled, buffer
+    if (
+      !ws ||
+      ws.readyState !== WebSocket.OPEN ||
+      !capture.isNetworkLoggingEnabled()
+    ) {
+      buffer.push(message);
+      if (buffer.length > MAX_BUFFER_SIZE) buffer.shift();
+      return;
+    }
+
+    sendMessage(message);
+  };
+
+  const flushBuffer = () => {
+    if (
+      !ws ||
+      ws.readyState !== WebSocket.OPEN ||
+      !capture.isNetworkLoggingEnabled()
+    ) {
+      return;
+    }
+
+    debugLogger.debug(`Flushing ${buffer.length} buffered logs...`);
+    while (buffer.length > 0) {
+      const message = buffer.shift()!;
+      sendMessage(message);
+    }
+  };
+
+  const cleanup = () => {
+    if (pingInterval) {
+      clearInterval(pingInterval);
+      pingInterval = null;
+    }
+    ws = null;
+  };
+
+  const scheduleReconnect = () => {
+    if (reconnectTimer) return;
+
+    reconnectTimer = setTimeout(() => {
+      reconnectTimer = null;
+      debugLogger.debug('Reconnecting WebSocket...');
+      connect();
+    }, 5000);
+  };
+
+  // Initial connection
+  connect();
+
+  capture.on('console', (payload) => sendToNetwork('console', payload));
+  capture.on('network', (payload) => sendToNetwork('network', payload));
+  capture.on('network-logging-enabled', () => {
+    debugLogger.debug('Network logging enabled, flushing buffer...');
+    flushBuffer();
+  });
+
+  // Cleanup on process exit
+  process.on('exit', () => {
+    if (reconnectTimer) clearTimeout(reconnectTimer);
+    if (ws) ws.close();
+    cleanup();
+  });
+}
+
+/**
+ * Registers the activity logger if debug mode and interactive session are enabled.
+ * Captures network and console logs to a session-specific JSONL file or sends to network.
  *
- * The log file location can be overridden via the GEMINI_CLI_ACTIVITY_LOG_FILE
- * environment variable. If not set, defaults to logs/session-{sessionId}.jsonl
- * in the project's temp directory.
+ * Environment variable GEMINI_CLI_ACTIVITY_LOG_TARGET controls the output:
+ * - host:port format (e.g., "localhost:25417") → network mode (auto-enabled)
+ * - file path (e.g., "/tmp/logs.jsonl") → file mode (immediate)
+ * - not set → uses default file location in project temp logs dir
  *
  * @param config The CLI configuration
  */
 export function registerActivityLogger(config: Config) {
-  if (config.storage) {
-    const capture = ActivityLogger.getInstance();
-    capture.enable();
+  const target = process.env['GEMINI_CLI_ACTIVITY_LOG_TARGET'];
+  const hostPort = target ? parseHostPort(target) : null;
 
-    const logsDir = config.storage.getProjectTempLogsDir();
-    if (!fs.existsSync(logsDir)) {
-      fs.mkdirSync(logsDir, { recursive: true });
-    }
-
-    const logFile =
-      process.env['GEMINI_CLI_ACTIVITY_LOG_FILE'] ||
-      path.join(logsDir, `session-${config.getSessionId()}.jsonl`);
-
-    const writeToLog = (type: 'console' | 'network', payload: unknown) => {
-      try {
-        const entry =
-          JSON.stringify({
-            type,
-            payload,
-            timestamp: Date.now(),
-          }) + '\n';
-
-        // Use asynchronous fire-and-forget to avoid blocking the event loop
-        fs.promises.appendFile(logFile, entry).catch((err) => {
-          debugLogger.error('Failed to write to activity log:', err);
-        });
-      } catch (err) {
-        debugLogger.error('Failed to prepare activity log entry:', err);
-      }
-    };
-
-    capture.on('console', (payload) => writeToLog('console', payload));
-    capture.on('network', (payload) => writeToLog('network', payload));
-
-    // Bridge CoreEvents to local capture
-    coreEvents.on(CoreEvent.ConsoleLog, (payload) => {
-      capture.logConsole(payload);
-    });
+  // Network mode doesn't need storage; file mode does
+  if (!hostPort && !config.storage) {
+    return;
   }
+
+  const capture = ActivityLogger.getInstance();
+  capture.enable();
+
+  if (hostPort) {
+    // Network mode: send logs via WebSocket
+    setupNetworkLogging(capture, hostPort.host, hostPort.port, config);
+    // Auto-enable network logging when target is explicitly configured
+    capture.enableNetworkLogging();
+  } else {
+    // File mode: write to JSONL file
+    setupFileLogging(capture, config, target);
+  }
+
+  // Bridge CoreEvents to local capture
+  coreEvents.on(CoreEvent.ConsoleLog, (payload) => {
+    capture.logConsole(payload);
+  });
 }