AnthropicStructuredOutput.ts

AnthropicStructuredOutput.ts overview

Adapts Effect Schema codecs to the JSON Schema subset accepted by Anthropic structured output.

The main entry point returns the JSON Schema to send to Anthropic and a codec for decoding the model response back into the original application type. When Anthropic cannot express the original schema shape directly, the conversion rewrites supported cases such as tuples, records, optional properties, and oneOf unions. Schema kinds that cannot be represented throw during conversion instead of producing a lossy schema.

Since v4.0.0

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Exports Grouped by Category

• Codec Transformation
  • toCodecAnthropic

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Codec Transformation

toCodecAnthropic

Converts a Schema.Codec to Anthropic structured-output JSON Schema and a matching codec for model output.

When to use

Use when you send Effect Schema-backed structured output requests to Anthropic and need provider-compatible JSON Schema without losing the decoded application type.

Details

Returns the JSON Schema to include in the request and the codec to use when decoding the model response. If the input schema already fits Anthropic’s supported JSON Schema subset, the original codec is returned unchanged.

Gotchas

• Some schemas use a provider-safe encoded shape: tuples become objects with numeric string keys, records become arrays of [key, value] pairs, and optional properties become required nullable properties.
• oneOf unions are emitted as anyOf unions.
• Unsupported schema kinds throw during conversion instead of producing a lossy schema.

See

• LanguageModel.CodecTransformer for the structured-output transformer contract
• OpenAiStructuredOutput.toCodecOpenAI for the OpenAI-specific transformer

Signature

declare const toCodecAnthropic: <T, E, RD, RE>(
  schema: Schema.ConstraintCodec<T, E, RD, RE>
) => { readonly codec: Schema.ConstraintCodec<T, unknown, RD, RE>; readonly jsonSchema: JsonSchema.JsonSchema }

Source

Since v4.0.0