Tracing - effect-orpc

export const router = { users: { // span name: "users.get" get: effectProcedure.effect(function* () { const usersRepo = yield* UsersRepo; return yield* usersRepo.findById("1"); }), }, };

Override the span name

Use .traced(...) when a stable custom span name is better than the router path.

custom-span.ts

const getUser = effectProcedure
  .input(z.object({ id: z.string() }))
  .traced("users.get_by_id")
  .effect(function* ({ input }) {
    const usersRepo = yield* UsersRepo;
    return yield* usersRepo.findById(input.id);
  });

User spans inside procedure spans

Effect-returning callbacks keep their own spans inside the automatic procedure span. This is useful when you use named Effect.fn(...) helpers or Effect.withSpan(...) inside handlers, providers, or middleware.

named-effect-fn.ts

const getUser = effectProcedure.effect(
  Effect.fn("users.repo.lookup")(function* ({ input }) {
    const usersRepo = yield* UsersRepo;
    return yield* usersRepo.findById(input.id);
  }),
);

Error stack traces

When an Effect procedure fails, effect-orpc captures stack information near the procedure definition site so spans point to useful application code.

example-stack.txt

UserNotFoundError: User not found
    at <anonymous> (/app/src/router.ts:42:28)
    at users.get (/app/src/router.ts:40:35)

This page covers the tracing capability. To wire spans to an OpenTelemetry exporter, see OpenTelemetry guide.

​Override the span name

​User spans inside procedure spans

​Error stack traces

​Next step

Override the span name

User spans inside procedure spans

Error stack traces

Next step