AI_StreamProviderError

This error represents a well-formed error event reported by a provider after a model response stream has started. The AI SDK exposes it in streaming error parts and callbacks such as the streamText onError callback.

Properties

• message: The provider error message
• type: The provider-defined error type (optional)
• code: The provider-defined error code as a string or number (optional)
• statusCode: The HTTP-equivalent status code when supplied by or inferable from provider metadata (optional)
• isRetryable: Whether retrying the model call may succeed
• data: The original provider error payload (optional)
• cause: The underlying error that caused the failure (optional)

isRetryable is a retry classification, not an automatic retry. A stream may already contain partial output, so applications should decide whether to discard, replace, or preserve that output before starting another model call.

Checking for this Error

Use StreamProviderError.isInstance so identification also works when multiple AI SDK versions are present:

Gateway

Provider

Custom

Grok 4.6

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import { StreamProviderError, streamText } from 'ai';
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const result = streamText({
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  model: "xai/grok-4.6",
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  prompt: 'Write a vegetarian lasagna recipe for 4 people.',
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  onError: ({ error }) => {
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    if (StreamProviderError.isInstance(error) && error.isRetryable) {
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      // Schedule an application-managed retry.
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    }
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  },
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});

Providers may not include enough metadata to determine a status code. In that case, statusCode is undefined, and retryability is classified conservatively. Provider-specific status and retry mappings are supplied by the provider adapter rather than inferred from arbitrary provider error type or code substrings. Provider type and code values are preserved independently, even when a numeric code is also used to determine statusCode. Errors that are already Error instances and malformed or unknown provider values are preserved unchanged.