Symptom
Apps using the MCP Python client log ResourceWarning about unclosed MemoryObjectReceiveStream and MemoryObjectSendStream.
Evidence what you'll see
- ResourceWarning: Unclosed <MemoryObjectReceiveStream ...>
- Raised from the stream library's memory streams
- Seen with the stdio client
Cause
Per-request response streams in the session were not always closed and removed, especially when a request raised, so they piled up.
Fix steps
0 of 1 done
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Verify the fix worked
- Run the client with warnings enabled and confirm no unclosed-stream warnings appear on exit.
Sources and credit
Summarized in our own words from these public reports. Credit goes to their authors.
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