Standard Schema Integration

oRPC natively supports any library that implements the Standard Schema specification, such as Zod, Valibot, ArkType, and many more. Use them directly in .input, .output, and .errors without any extra setup.

import * as z from 'zod'
import * as v from 'valibot'

const example = os
  .input(z.object({ name: z.string() }))
  .output(v.object({ name: v.string() }))

Standard JSON Schema

Standard JSON Schema is a companion specification that lets a schema library expose JSON Schema conversion in a standard way. Tools that rely on JSON Schema converters, such as the OpenAPI Generator and Smart Coercion, automatically fall back to Standard JSON Schema conversion when no configured converter matches a schema. So if your library also implements Standard JSON Schema, these tools work out of the box without a dedicated converter. Otherwise, the schema is treated as unknown and converted to an empty JSON schema.

Building Your Own Converter

If your library does not implement Standard JSON Schema, or you want more control over the conversion, you can build your own converter by implementing the JsonSchemaConverter interface and passing it to the converters option. The first converter whose condition matches handles the schema:

import type { AnySchema } from '@orpc/contract'
import type {
  JsonSchema,
  JsonSchemaConverter,
  JsonSchemaConverterDirection
} from '@orpc/json-schema'
import { toJsonSchema } from '@valibot/to-json-schema'

class MyCustomConverter implements JsonSchemaConverter {
  condition(schema: AnySchema | undefined, _direction: JsonSchemaConverterDirection): boolean {
    return schema?.['~standard'].vendor === 'valibot'
  }

  convert(
    schema: AnySchema | undefined,
    direction: JsonSchemaConverterDirection
  ): [jsonSchema: JsonSchema, optional: boolean] {
    // In most cases, treating the schema as required is acceptable.
    return [toJsonSchema(schema as any), false] as any
  }
}