@opencode-ai/client: zero-Effect Promise client using fetch.
@opencode-ai/client/effect: rich Effect network client using an environment-provided HttpClient.
@opencode-ai/client/effect/embedded: scoped embedded OpenCode host backed by Core and the in-memory HTTP router.

The generated surface contains sessions.list, create, get, switchAgent, switchModel, prompt, compact, wait, and context. The server and generator consume the exact same hosted SessionGroup. Run bun run generate after changing that contract and bun run check:generated to detect committed-output drift.

During alpha, the Effect network entrypoint accepts the authoritative group's heavy Core/server import graph. The intended stable design keeps the same group while isolating its schema and middleware-tag dependencies into lightweight modules. The migration checklist is recorded in CONTEXT.md under "Deferred client contract cleanup."

The embedded entrypoint exposes a scoped host backed by the same server router, middleware, handlers, and HTTP codecs as the network client:

import { OpenCode } from "@opencode-ai/client/effect/embedded"

const opencode = yield * OpenCode.create()
const session = yield * opencode.sessions.get({ sessionID })

It also exposes embedded-only tools.register(...). Closing the owning Effect Scope releases the router resources, location services, fibers, and scoped tool registrations.

Effect applications can provide the same scoped constructor as a service Layer:

const program = Effect.gen(function* () {
  const opencode = yield* OpenCode.Service
  return yield* opencode.sessions.get({ sessionID })
})

yield * program.pipe(Effect.provide(OpenCode.layer))

OpenCode.layer is only a dependency-injection adapter over OpenCode.create(); it does not define another embedded implementation.

The beta embedded host currently assumes one active host per database. Multiple hosts sharing durable Session storage require shared process-local execution coordination and remain deferred together with embedded streaming support.