structuredValidator

@forge/monorepo

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@forge/monorepo / backend/src / structuredValidator

Function: structuredValidator()

structuredValidator(schema): (value) => { ok: true; } | { detail: string; ok: false; }

Defined in: backend/src/models/streaming.ts:252

A schema this process can actually check, or a refusal — task #243.

The rule: only a schema with a validator is accepted for structured output. Zod (a direct dependency) and anything else implementing Standard Schema qualify. A bare JSON-schema object does not, and refusing it is a deliberate choice rather than an omission:

• The AI SDK's jsonSchema() wrapper returns { _type, jsonSchema, validate } with validate undefined. It constrains the provider's generation and validates nothing coming back. Accepting one would mean the platform says "structured", the provider mostly complies, and nobody checks — which is a softer version of the bug being fixed, not a fix.
• Validating JSON schema properly needs ajv, and that is a new runtime dependency for every consumer of a package whose entire dependency list is ai and zod. Not worth it when z.object({...}) is one line and already validates.

So this fails closed, at wiring time, with a message naming the fix. Tools keep taking JSON schema — a tool's arguments are validated by the provider and a bad call is a tool error the model can see and retry, which is a different situation from a guarantee made to a caller about a return value.

Parameters

schema

unknown

Returns

(value) => { ok: true; } | { detail: string; ok: false; }