@ai-sdk/anthropic/src/map-anthropic-stop-reason.ts

The **[Anthropic provider](https://ai-sdk.dev/providers/ai-sdk-providers/anthropic)** for the [AI SDK](https://ai-sdk.dev/docs) contains language model support for the [Anthropic Messages API](https://docs.anthropic.com/claude/reference/messages_post).

import { LanguageModelV3FinishReason } from '@ai-sdk/provider';

/**
 * @see https://docs.anthropic.com/en/api/messages#response-stop-reason
 */
export function mapAnthropicStopReason({
  finishReason,
  isJsonResponseFromTool,
}: {
  finishReason: string | null | undefined;
  isJsonResponseFromTool?: boolean;
}): LanguageModelV3FinishReason['unified'] {
  switch (finishReason) {
    case 'pause_turn':
    case 'end_turn':
    case 'stop_sequence':
      return 'stop';
    case 'refusal':
      return 'content-filter';
    case 'tool_use':
      return isJsonResponseFromTool ? 'stop' : 'tool-calls';
    case 'max_tokens':
    case 'model_context_window_exceeded':
      return 'length';
    case 'compaction':
      return 'other';
    default:
      return 'other';
  }
}