📄 ai-sdk/docs/troubleshooting/use-chat-an-error-occurred
File: use-chat-an-error-occurred.md | Updated: 11/15/2025
Source: https://ai-sdk.dev/docs/troubleshooting/use-chat-an-error-occurred
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AI SDK 5.x
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Stale body values with useChat
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React error "Maximum update depth exceeded"
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I am using useChat
and I get the error "An error occurred".
Error messages from streamText are masked by default when using toDataStreamResponse for security reasons (secure-by-default). This prevents leaking sensitive information to the client.
To forward error details to the client or to log errors, use the getErrorMessage function when calling toDataStreamResponse.
export function errorHandler(error: unknown) { if (error == null) { return 'unknown error'; }
if (typeof error === 'string') { return error; }
if (error instanceof Error) { return error.message; }
return JSON.stringify(error);}
const result = streamText({ // ...});
return result.toUIMessageStreamResponse({ getErrorMessage: errorHandler,});
In case you are using createDataStreamResponse, you can use the onError function when calling toDataStreamResponse:
const response = createDataStreamResponse({ // ... async execute(dataStream) { // ... }, onError: errorHandler,});
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