zmo-cli/packages/opencode/specs/effect/routes.md

Route handler effectification

Practical reference for converting server route handlers in packages/opencode to a single AppRuntime.runPromise(Effect.gen(...)) body.

Goal

Route handlers should wrap their entire body in a single AppRuntime.runPromise(Effect.gen(...)) call, yielding services from context rather than calling facades one-by-one.

This eliminates multiple runPromise round-trips and lets handlers compose naturally.

// Before - one facade call per service
;async (c) => {
  await SessionRunState.assertNotBusy(id)
  await Session.removeMessage({ sessionID: id, messageID })
  return c.json(true)
}

// After - one Effect.gen, yield services from context
;async (c) => {
  await AppRuntime.runPromise(
    Effect.gen(function* () {
      const state = yield* SessionRunState.Service
      const session = yield* Session.Service
      yield* state.assertNotBusy(id)
      yield* session.removeMessage({ sessionID: id, messageID })
    }),
  )
  return c.json(true)
}

Rules

• Wrap the whole handler body in one AppRuntime.runPromise(Effect.gen(...)) call when the handler is service-heavy.
• Yield services from context instead of calling async facades repeatedly.
• When independent service calls can run in parallel, use Effect.all(..., { concurrency: "unbounded" }).
• Prefer one composed Effect body over multiple separate runPromise(...) calls in the same handler.

Current route files

Current instance route files live under src/server/routes/instance/httpapi. Most handlers already yield stable services at route-layer construction and then close over those services in endpoint implementations.

Files still worth tracking here:

• handlers/session.ts — still the heaviest mixed file; some paths keep compatibility translations and direct event publication
• handlers/experimental.ts — mixed state; some handlers still rely on request-local context reads
• middleware/* — still contains compatibility policy for auth, compression, errors, instance context, and workspace routing
• public.ts — still owns SDK/OpenAPI compatibility translation shims
• raw route modules — WebSocket and catch-all routes should stay explicit and avoid rebuilding stable layers per request

Notes

• Route conversion is now less about backend migration and more about removing the remaining direct Instance.* reads, request-local service plumbing, and OpenAPI compatibility shims.
• Prefer route-layer service capture over rebuilding or providing stable layers inside individual handlers.