fix(trace-server): default MCP port to --port + 1 to avoid conflicts#92831
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…nt --port values don't conflict. Co-Authored-By: Claude <noreply@anthropic.com>
mischnic
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Apr 15, 2026
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What?
When
--mcp-portis not explicitly provided tonext internal trace, the MCP HTTP server now defaults to--port + 1(the WebSocket port plus one) instead of the hardcoded value5748.The
DEFAULT_WS_PORTremains5747, so when neither flag is passed the behavior is unchanged: WS=5747, MCP=5748.Why?
Starting the trace server twice with different
--portvalues (e.g. to analyze two trace files simultaneously) caused both instances to attempt to bind the same hardcoded MCP port5748:Making the MCP port default relative to the WS port means each invocation with a unique
--portautomatically gets a unique--mcp-portwithout any extra flags.How?
In
startTurboTraceServerCli, changed:to:
The now-unused
DEFAULT_MCP_PORTconstant inturbo-trace-server.tswas removed. The identical constant inquery-trace.tsis kept — it is the client-side default for connecting to an MCP server and5748remains a sensible default there.The
--mcp-porthelp text was updated to reflect the dynamic default.