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

[SandyTao520]

Summary

Add WebSocket client support to the activity logger for real-time log transmission to external DevTools, and support streaming chunks in the fetch API by reading ReadableStream.

Details

• Add WebSocket client in activityLogger.ts for real-time log transmission to DevTools
• Support streaming chunks by reading ReadableStream from fetch API responses
• Add reconnection and buffering logic — logs are buffered when disconnected and replayed on reconnect
• Support GEMINI_CLI_ACTIVITY_LOG_TARGET environment variable for configuring host:port
• Add parseHostPort utility function
• Enable/disable network logging dynamically
• Add ws package dependency

Related Issues

#18007

How to Validate

1. Set GEMINI_CLI_ACTIVITY_LOG_TARGET=localhost:9100 environment variable
2. Run the CLI and make a request
3. Observe that activity logs are sent via WebSocket to the specified host:port
4. Kill the WebSocket server and verify logs are buffered
5. Restart the server and verify buffered logs are replayed

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any)
• Validated on required platforms/methods:
  • MacOS
    • npm run
    • npx
    • Docker
    • Podman
    • Seatbelt
  • Windows
    • npm run
    • npx
    • Docker
  • Linux
    • npm run
    • npx
    • Docker

[gemini-cli]

Hi @SandyTao520, thank you so much for your contribution to Gemini CLI! We really appreciate the time and effort you've put into this.

We're making some updates to our contribution process to improve how we track and review changes. Please take a moment to review our recent discussion post: Improving Our Contribution Process & Introducing New Guidelines.

Key Update: Starting January 26, 2026, the Gemini CLI project will require all pull requests to be associated with an existing issue. Any pull requests not linked to an issue by that date will be automatically closed.

Thank you for your understanding and for being a part of our community!

[gemini-cli]

Hi there! Thank you for your contribution to Gemini CLI.

To improve our contribution process and better track changes, we now require all pull requests to be associated with an existing issue, as announced in our recent discussion and as detailed in our CONTRIBUTING.md.

This pull request is being closed because it is not currently linked to an issue. Once you have updated the description of this PR to link an issue (e.g., by adding Fixes #123 or Related to #123), it will be automatically reopened.

How to link an issue:
Add a keyword followed by the issue number (e.g., Fixes #123) in the description of your pull request. For more details on supported keywords and how linking works, please refer to the GitHub Documentation on linking pull requests to issues.

Thank you for your understanding and for being a part of our community!

[gemini-code-assist]

Summary of Changes

Hello @SandyTao520, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the CLI's activity logging capabilities by integrating WebSocket-based real-time log transmission and enabling detailed streaming of network response chunks. This allows developers to monitor CLI activity and network interactions in external DevTools, improving debugging and observability, especially for long-running or streaming operations. The new system includes robust reconnection and buffering mechanisms to ensure log integrity even during temporary disconnections.

Highlights

• WebSocket-based Network Logging: Introduces a WebSocket client to the activity logger for real-time transmission of logs to external DevTools, enhancing observability.
• Streaming Chunk Support: Adds support for streaming chunks in network requests by reading ReadableStream from fetch API responses, allowing for detailed monitoring of partial responses.
• Robust Connection Handling: Implements reconnection and buffering logic for WebSocket connections, ensuring logs are buffered when disconnected and replayed upon successful reconnection.
• Configurable Logging Target: Introduces the GEMINI_CLI_ACTIVITY_LOG_TARGET environment variable, allowing users to specify a host:port for WebSocket logging or a file path for traditional logging.
• Dynamic Logging Control: Enables dynamic control over network logging, allowing it to be activated or deactivated as needed, and includes a utility function to parse host:port strings.

Changelog

• evals/test-helper.ts
  • Updated test environment variable from GEMINI_CLI_ACTIVITY_LOG_FILE to GEMINI_CLI_ACTIVITY_LOG_TARGET.
• package-lock.json
  • Added ws and @types/ws dependencies for WebSocket functionality.
• packages/cli/package.json
  • Added ws and @types/ws as project dependencies.
• packages/cli/src/nonInteractiveCli.test.ts
  • Modified activity logger tests to reference the new GEMINI_CLI_ACTIVITY_LOG_TARGET environment variable.
• packages/cli/src/nonInteractiveCli.ts
  • Updated the condition for registering the activity logger to check for GEMINI_CLI_ACTIVITY_LOG_TARGET.
• packages/cli/src/utils/activityLogger.ts
  • Integrated WebSocket client for network logging.
  • Added parseHostPort utility for environment variable configuration.
  • Extended NetworkLog interface to support chunk data for streaming responses.
  • Introduced methods to enableNetworkLogging, disableNetworkLogging, and check isNetworkLoggingEnabled.
  • Enhanced fetch and http.request interception to handle and emit streaming response chunks.
  • Refactored registerActivityLogger to dynamically switch between file-based and WebSocket-based logging based on GEMINI_CLI_ACTIVITY_LOG_TARGET.
  • Implemented setupNetworkLogging with WebSocket connection, buffering, reconnection, and ping/pong mechanisms.
  • Created setupFileLogging for traditional file-based log output.

Activity

• The pull request was authored by SandyTao520.
• The description provides a detailed summary, specific implementation details, and a validation guide.
• The pre-merge checklist indicates that the changes have been validated on MacOS using npm run.
• No related issues are noted in the PR description.

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[gemini-code-assist]

Code Review

This pull request introduces significant enhancements to activity logging by adding WebSocket support for real-time log transmission and handling of streaming API responses. The implementation includes robust features like log buffering and automatic reconnection for the WebSocket client. My review identifies a critical regression that restricts the activity logger's activation, breaking existing logging functionality for non-interactive sessions. Additionally, I've found a high-severity issue in the new parseHostPort utility function that can lead to incorrect parsing of certain network addresses. I've provided detailed comments and code suggestions to address these issues, ensuring the new features are both powerful and reliable.

[github-actions]

Size Change: +6.95 kB (+0.03%)

Total Size: 23.8 MB

Filename	Size	Change
./bundle/gemini.js	23.8 MB	+6.95 kB (+0.03%)

ℹ️ View Unchanged

Filename	Size
./bundle/sandbox-macos-permissive-closed.sb	1.03 kB
./bundle/sandbox-macos-permissive-open.sb	890 B
./bundle/sandbox-macos-permissive-proxied.sb	1.31 kB
./bundle/sandbox-macos-restrictive-closed.sb	3.29 kB
./bundle/sandbox-macos-restrictive-open.sb	3.36 kB
./bundle/sandbox-macos-restrictive-proxied.sb	3.56 kB

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