Add orpc error schemas to common schemas in OpenAPI

[mykyta-burkovskyi]

Describe the feature

OpenAPI spec generator allows to specify UndefinedError schema in commonSchemas, but I didn't find any way to add schemas for other common orpc errors to commonSchemas.

It would be nice to be able to add other errors to commonSchemas so that endpoint responses use $ref for reduced overall spec size

Additional information

• Would you be willing to help implement this feature?

[unnoq]

It should be better if orpc can build-in, but for now you can custom with https://orpc.dev/docs/openapi/advanced/customizing-error-response#openapigenerator

[maximilian-hammerl]

@unnoq, could you give more details or maybe an example how to accomplish this with customErrorResponseBodySchema?

I have a rate limiting middleware, simplified:

import * as z from 'zod'

const TOO_MANY_REQUESTS_ERROR_DATA = z.object({
  limit: z.int().nonnegative().optional(),
  remaining: z.int().nonnegative().optional(),
  reset: z.int().nonnegative().optional(),
})

export default base
  .errors({
    TOO_MANY_REQUESTS: { data: TOO_MANY_REQUESTS_ERROR_DATA },
  })
  .middleware(async ({ next, errors }) => {
    const key = `...`
    const result = await ratelimiter.limit(key)

    if (!result.success) {
      throw errors.TOO_MANY_REQUESTS({
        data: {
          limit: result.limit,
          remaining: result.remaining,
          reset: result.reset,
        },
      })
    }

    return next()
  })

My goal is that all endpoints which use this middleware have the TOO_MANY_REQUESTS response defined in the OpenAPI specification of these endpoints.

[unnoq]

My goal is that all endpoints which use this middleware have the TOO_MANY_REQUESTS response defined in the OpenAPI specification of these endpoints.

This will (99%) support out-of-the box in oRPC v2, but for now you need redefine .errors in your procedure to make it visible in client/spec