Symptom
Streaming a LangGraph.js graph in React Native fails with 'This stream has already been locked for exclusive reading by another reader'.
Evidence what you'll see
- Happens with web-streams-polyfill loaded
- Setting streaming: false on the model doesn't help
- Seen on @langchain/langgraph 0.3.x
Cause
A private _reader field in the library's stream wrapper shadowed the polyfill's own field, so the polyfill checked the wrong reader and thought the stream was locked.
Fix steps
0 of 1 done
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Verify the fix worked
- Stream the graph in the app and confirm chunks arrive without the locked-stream error.
Sources and credit
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