Errors

All SDK errors extend FoundationModelsError. Import specific error classes to handle them individually.

Hierarchy

FoundationModelsError
├── GenerationError
│   ├── ExceededContextWindowSizeError
│   ├── AssetsUnavailableError
│   ├── GuardrailViolationError
│   ├── UnsupportedGuideError
│   ├── UnsupportedLanguageOrLocaleError
│   ├── DecodingFailureError
│   ├── RateLimitedError
│   ├── ConcurrentRequestsError
│   ├── RefusalError
│   └── InvalidGenerationSchemaError
└── ToolCallError

Error Reference

Error	Code	When
ExceededContextWindowSizeError	1	Session history too long
AssetsUnavailableError	2	Model not downloaded
GuardrailViolationError	3	Content policy violation
UnsupportedGuideError	4	Unsupported generation guide
UnsupportedLanguageOrLocaleError	5	Language not supported
DecodingFailureError	6	Structured output parse failure
RateLimitedError	7	Too many requests
ConcurrentRequestsError	8	Session already responding
RefusalError	9	Model declined to answer
InvalidGenerationSchemaError	10	Malformed schema
ToolCallError	—	Tool's call() threw

GenerationErrorCode

Enum mapping status codes to error types:

enum GenerationErrorCode {
  SUCCESS = 0,
  EXCEEDED_CONTEXT_WINDOW_SIZE = 1,
  ASSETS_UNAVAILABLE = 2,
  GUARDRAIL_VIOLATION = 3,
  UNSUPPORTED_GUIDE = 4,
  UNSUPPORTED_LANGUAGE_OR_LOCALE = 5,
  DECODING_FAILURE = 6,
  RATE_LIMITED = 7,
  CONCURRENT_REQUESTS = 8,
  REFUSAL = 9,
  INVALID_SCHEMA = 10,
  UNKNOWN_ERROR = 255,
}

Usage

import {
  FoundationModelsError,
  GenerationError,
  ExceededContextWindowSizeError,
  GuardrailViolationError,
  ToolCallError,
} from "tsfm-sdk";

try {
  await session.respond("...");
} catch (e) {
  if (e instanceof ToolCallError) {
    // Tool handler threw
  } else if (e instanceof GenerationError) {
    // Any generation error
  } else if (e instanceof FoundationModelsError) {
    // Any SDK error
  }
}