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# LanguageModelError

A failure that may occur while generating a response when using any language model.

```
enum LanguageModelError
```

## Topics

### Exceeded context size error

[`case contextSizeExceeded(LanguageModelError.ContextSizeExceeded)`](/documentation/FoundationModels/LanguageModelError/contextSizeExceeded(_:))

The session’s transcript exceeded the model’s context size.

[`struct ContextSizeExceeded`](/documentation/FoundationModels/LanguageModelError/ContextSizeExceeded)

Information about exceeding the context window size.

### Session rate limited error

[`case rateLimited(LanguageModelError.RateLimited)`](/documentation/FoundationModels/LanguageModelError/rateLimited(_:))

The session has been rate limited.

[`struct RateLimited`](/documentation/FoundationModels/LanguageModelError/RateLimited)

Information about a rate limiting event.

### Model refusal error

[`case refusal(LanguageModelError.Refusal)`](/documentation/FoundationModels/LanguageModelError/refusal(_:))

The model refused to answer.

[`struct Refusal`](/documentation/FoundationModels/LanguageModelError/Refusal)

Information about a model refusal.

### Request timed out error

[`case timeout(LanguageModelError.Timeout)`](/documentation/FoundationModels/LanguageModelError/timeout(_:))

The request timed out before the model could produce a response.

[`struct Timeout`](/documentation/FoundationModels/LanguageModelError/Timeout)

Information about a timeout.

### Safety guardrail error

[`case guardrailViolation(LanguageModelError.GuardrailViolation)`](/documentation/FoundationModels/LanguageModelError/guardrailViolation(_:))

The model’s safety guardrails were triggered by content in a
prompt or the response generated by the model.

[`struct GuardrailViolation`](/documentation/FoundationModels/LanguageModelError/GuardrailViolation)

Information about a guardrail violation.

### Capability unsupported error

[`case unsupportedCapability(LanguageModelError.UnsupportedCapability)`](/documentation/FoundationModels/LanguageModelError/unsupportedCapability(_:))

The model being used doesn’t support a particular feature.

[`struct UnsupportedCapability`](/documentation/FoundationModels/LanguageModelError/UnsupportedCapability)

Information about an unsupported capability.

### Transcript content unsupported error

[`case unsupportedTranscriptContent(LanguageModelError.UnsupportedTranscriptContent)`](/documentation/FoundationModels/LanguageModelError/unsupportedTranscriptContent(_:))

The prompt contains content that the model cannot process.

[`struct UnsupportedTranscriptContent`](/documentation/FoundationModels/LanguageModelError/UnsupportedTranscriptContent)

Information about unsupported prompt content.

### Generation guide unsupported error

[`case unsupportedGenerationGuide(LanguageModelError.UnsupportedGenerationGuide)`](/documentation/FoundationModels/LanguageModelError/unsupportedGenerationGuide(_:))

An unsupported generation guide was used

[`struct UnsupportedGenerationGuide`](/documentation/FoundationModels/LanguageModelError/UnsupportedGenerationGuide)

Information about an unsupported generation guide.

### Language unsupported error

[`case unsupportedLanguageOrLocale(LanguageModelError.UnsupportedLanguageOrLocale)`](/documentation/FoundationModels/LanguageModelError/unsupportedLanguageOrLocale(_:))

The model was prompted to respond in a language that it does not support.

[`struct UnsupportedLanguageOrLocale`](/documentation/FoundationModels/LanguageModelError/UnsupportedLanguageOrLocale)

Information about an unsupported language or locale.

## Relationships

### Conforms To

[`LocalizedError`](/documentation/Foundation/LocalizedError)

[`Copyable`](/documentation/Swift/Copyable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Error`](/documentation/Swift/Error)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`Escapable`](/documentation/Swift/Escapable)

[`Sendable`](/documentation/Swift/Sendable)

---

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