fix: redirect stdio banner to stderr to prevent MCP protocol pollution - #1209
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3ni8ma wants to merge 1 commit into
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fix: redirect stdio banner to stderr to prevent MCP protocol pollution#12093ni8ma wants to merge 1 commit into
3ni8ma wants to merge 1 commit into
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In stdio mode, stdout is reserved for JSON-RPC messages. The startup banner was being printed to stdout, which broke MCP clients like Claude Code that strictly follow the stdio protocol. This fix redirects the banner to stderr when transport='stdio', keeping stdout clean for JSON-RPC communication. Closes sansan0#1204
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Description
In stdio mode, stdout is reserved for JSON-RPC messages. The startup banner was being printed to stdout, which broke MCP clients like Claude Code that strictly follow the stdio protocol.
Fix
Redirect the banner to stderr when transport='stdio', keeping stdout clean for JSON-RPC communication.
Changes
Closes #1204