imatza-rh/mcp-zuul

What's New

stream_build_console — read live console output from RUNNING Zuul builds.

Until now, all log tools (tail_build_log, get_build_log, browse_build_logs) required log_url which only exists after post-run completes. When a job is running, there was no way to see its output. This tool connects to Zuul's WebSocket console-stream endpoint, buffers for N seconds, and returns the last M lines (tail behavior).

Install

pip install mcp-zuul[console]    # adds websockets dependency

The [console] extra is optional — users who don't need live streaming skip the dependency. The tool returns a clear install message when called without it.

Usage

stream_build_console(uuid="abc123", timeout=10, lines=50)

• timeout: seconds to buffer (default 10, max 30)
• lines: tail line count (default 100, max 500)
• Accepts url param (paste a Zuul build URL) like other build tools

Added

• New tool: stream_build_console — live console output from RUNNING builds via WebSocket
• New optional extra: [console] installs websockets>=14.0
• _no_log_url_error now suggests stream_build_console for IN_PROGRESS builds

Technical Details

• Auth via JWT token in the WebSocket message body (not HTTP headers), verified against upstream Zuul source
• Line reassembly across chunk boundaries (Zuul streams raw 4KB chunks from the executor's finger protocol)
• SSL: wss:// with configurable cert verification, ws:// for plain connections
• Error handling: specific messages for 403, 404, close codes 4000/4011, timeout, connection refused
• 33 tests, 99% coverage

Full Changelog: https://github.com/imatza-rh/mcp-zuul/blob/main/CHANGELOG.md#060---2026-04-26