Shield the stdio JSONRPC channel from app stdout writes#33
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marksibrahim merged 1 commit intoJun 11, 2026
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The MCP stdio transport uses stdout (fd 1) for protocol frames, but the served OpenApps app prints to stdout while handling requests (e.g. re-seeding a DB on navigation). Those prints interleave with the JSONRPC frames, desync the stream, and hang the client mid-episode. Wrap sys.stdout for the stdio transport so the real binary buffer still carries protocol frames while all text writes are redirected to stderr.
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The MCP stdio transport uses stdout (fd 1) for protocol frames, but the served OpenApps app prints to stdout while handling requests (e.g. re-seeding a DB on navigation). Those prints interleave with the JSONRPC frames, desync the stream, and hang the client mid-episode. Wrap sys.stdout for the stdio transport so the real binary buffer still carries protocol frames while all text writes are redirected to stderr.