Errors

Errors#

This page documents the exception classes for error handling.

Note

Swift Equivalent: GenerationError cooresponds to the the LanguageModelSession.GenerationError in the Swift Foundation Models Framework. ToolCallError corresponds to the LanguageModelSession.ToolCallError in the Swift Foundation Models Framework. InvalidGenerationSchemaError is unique to the Python SDK and does not have a direct Swift equivalent since it means a schema failed to compile in the underlying Swift.

Base Exceptions#

FoundationModelsError#

class apple_fm_sdk.FoundationModelsError[source]#

Bases: Exception

Base exception for Foundation Models errors.

Base exception for all Foundation Models SDK errors.

Generation Errors#

GenerationError#

class apple_fm_sdk.GenerationError[source]#

Bases: FoundationModelsError

Base class for generation-specific errors.

Base class for errors that occur during text generation.

ExceededContextWindowSizeError#

class apple_fm_sdk.ExceededContextWindowSizeError[source]#

Bases: GenerationError

Error thrown when the context window size is exceeded.

Raised when the input exceeds the model’s context window size.

AssetsUnavailableError#

class apple_fm_sdk.AssetsUnavailableError[source]#

Bases: GenerationError

Error thrown when required assets are unavailable.

Raised when required model assets are not available.

GuardrailViolationError#

class apple_fm_sdk.GuardrailViolationError[source]#

Bases: GenerationError

Error thrown when a guardrail violation occurs.

Raised when content violates safety guardrails. For more on the guardrails, see the Swift reference article on SystemLanguageModel safety meansures: Improving the safety of generative model output.

UnsupportedGuideError#

class apple_fm_sdk.UnsupportedGuideError[source]#

Bases: GenerationError

Error thrown when an unsupported guide is used.

Raised when an unsupported guide constraint is used.

UnsupportedLanguageOrLocaleError#

class apple_fm_sdk.UnsupportedLanguageOrLocaleError[source]#

Bases: GenerationError

Error thrown when an unsupported language or locale is used.

Raised when the requested language or locale is not supported.

DecodingFailureError#

class apple_fm_sdk.DecodingFailureError[source]#

Bases: GenerationError

Error thrown when decoding fails.

Raised when decoding the model’s output fails.

RateLimitedError#

class apple_fm_sdk.RateLimitedError[source]#

Bases: GenerationError

Error thrown when rate limited.

Raised when rate limits are exceeded. Rate limits do not apply to the on-device SystemLanguageModel on macOS so you should not encounter this error.

ConcurrentRequestsError#

class apple_fm_sdk.ConcurrentRequestsError[source]#

Bases: GenerationError

Error thrown when there are too many concurrent requests.

Raised when too many concurrent requests are made. The python SDK does not enforce concurrency limits so you should not encounter this error.

RefusalError#

class apple_fm_sdk.RefusalError[source]#

Bases: GenerationError

Error thrown when the model refuses to generate content.

Raised when the model refuses to generate a response _specifically_ for safety reasons on a generable output. For more on refusals, see the Swift reference article on SystemLanguageModel safety meansures: Improving the safety of generative model output.

Attributes:

  • reason (str): The reason for refusal

Schema Errors#

InvalidGenerationSchemaError#

class apple_fm_sdk.InvalidGenerationSchemaError[source]#

Bases: FoundationModelsError

Error thrown when a generation schema is invalid.

Raised when a generation schema is invalid. This means the schema failed to compile in the underlying Swift code and most commonly occurs if you give an invalid json schema to the json_schema parameter of the respond() method. This error may also occur if you use the @generable decorator on a class with properties that cannot be serialized to a json schema.

To validate if your json schema is valid, run the following code snippet in Swift:

import FoundationModels

jsonSchemaString = "..."  // Your JSON schema as a string

let schema = try JSONDecoder().decode(
  GenerationSchema.self,
  from: Data(jsonSchemaString.utf8)
)

The code above is the same validation step used in the Python SDK, so if it runs without throwing an error, your schema is valid.

For examples of what valid json schemas look like, see the tester schemas in the Github repo, such as tests/tester_schemas/hedgehog.json.

Tool Errors#

ToolCallError#

class apple_fm_sdk.ToolCallError[source]#

Bases: FoundationModelsError

Error thrown when a tool call fails.

Raised when a Tool call fails.

Attributes:

  • tool_name (str): Name of the tool that failed

  • underlying_error (Exception): The original exception

Contents