# @opencode-ai/sdk-next Effect-native scoped OpenCode host for in-process applications. This transitional package will replace the existing generated `@opencode-ai/sdk` after its consumers migrate. The SDK executes Server's assembled HTTP router in memory. It opens no listener and performs no network I/O, while preserving the same routing, middleware, handlers, codecs, and errors as the network client. ```ts import { OpenCode } from "@opencode-ai/sdk-next" const opencode = yield * OpenCode.create() const session = yield * opencode.sessions.get({ sessionID }) ``` It also exports `Tool` and exposes local-only `tools.register(...)`, replacing the former `@opencode-ai/core/public` facade. Registration uses Core's host-level `ApplicationTools` service shared by the host's Locations; each Location retains its own `ToolRegistry` for overlay, lookup, and settlement. Closing the owning Effect Scope releases router resources, location services, fibers, and scoped tool registrations. `sessions.events({ sessionID, after })` replays durable events after the optional aggregate sequence, then emits newly committed durable events. `sessions.interrupt(...)` targets execution owned by this host, and `sessions.message(...)` retrieves one projected Session message. The same constructor is available as a service Layer: ```ts 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` adapts `OpenCode.create()` for dependency injection; it does not define another host implementation.