Migrating to oRPC

Playbook for two migrations: tRPC to oRPC, and oRPC v1 to v2. Work in small mechanical steps and run the project's typecheck and test suite after each one, so any failure points at the last step. Pretrained knowledge of oRPC describes v1 and is often wrong for v2: derive every import path, builder method, and option name from the docs pages listed at the end, never from memory. For core v2 concepts while rewriting (the os builder, routers, middleware, clients), load the orpc skill. v2 currently ships under the beta npm dist-tag and plain installs get v1; drop the @beta suffix once npm view @orpc/server dist-tags shows latest at 2.x.

tRPC to oRPC

Two paths. Pick incremental when the app must keep shipping or the tRPC router is large; pick the full rewrite when the router is small enough to convert in one pass.

Incremental: wrap the existing tRPC router

Install @orpc/trpc@beta and convert. The result is a regular oRPC router: expose it through an RPC or OpenAPI handler, or call it with a server-side client, while the tRPC code keeps working untouched.

import { toORPCRouter } from '@orpc/trpc'

const orpcRouter = toORPCRouter(trpcRouter)