effectify Plugin service: migrate from Instance.state to Effect service pattern

Replace the legacy Instance.state() lazy-init pattern with the standard
Effect service pattern (Interface, Service class, Layer, promise facades).
Register Plugin.Service in InstanceServices and add its layer to the
instance lookup.

packages/opencode/specs/effect-migration.md

@@ -126,7 +126,7 @@ Done now:
 
 Still open and likely worth migrating:
 
-- [ ] `Plugin`
+- [x] `Plugin`
 - [ ] `ToolRegistry`
 - [ ] `Pty`
 - [ ] `Worktree`

packages/opencode/src/effect/instances.ts

@@ -10,6 +10,7 @@ import { ProviderAuth } from "@/provider/auth"
 import { Question } from "@/question"
 import { Skill } from "@/skill/skill"
 import { Snapshot } from "@/snapshot"
+import { Plugin } from "@/plugin"
 import { InstanceContext } from "./instance-context"
 import { registerDisposer } from "./instance-registry"
 
@@ -26,6 +27,7 @@ export type InstanceServices =
   | File.Service
   | Skill.Service
   | Snapshot.Service
+  | Plugin.Service
 
 // NOTE: LayerMap only passes the key (directory string) to lookup, but we need
 // the full instance context (directory, worktree, project). We read from the
@@ -46,6 +48,7 @@ function lookup(_key: string) {
     Layer.fresh(File.layer),
     Layer.fresh(Skill.defaultLayer),
     Layer.fresh(Snapshot.defaultLayer),
+    Layer.fresh(Plugin.layer),
   ).pipe(Layer.provide(ctx))
 }
 

packages/opencode/src/plugin/index.ts

@@ -5,13 +5,15 @@ import { Log } from "../util/log"
 import { createOpencodeClient } from "@opencode-ai/sdk"
 import { Server } from "../server/server"
 import { BunProc } from "../bun"
-import { Instance } from "../project/instance"
 import { Flag } from "../flag/flag"
 import { CodexAuthPlugin } from "./codex"
 import { Session } from "../session"
 import { NamedError } from "@opencode-ai/util/error"
 import { CopilotAuthPlugin } from "./copilot"
 import { gitlabAuthPlugin as GitlabAuthPlugin } from "@gitlab/opencode-gitlab-auth"
+import { Effect, Layer, ServiceMap } from "effect"
+import { InstanceContext } from "@/effect/instance-context"
+import { runPromiseInstance } from "@/effect/runtime"
 
 export namespace Plugin {
   const log = Log.create({ service: "plugin" })
@@ -19,126 +21,163 @@ export namespace Plugin {
   // Built-in plugins that are directly imported (not installed from npm)
   const INTERNAL_PLUGINS: PluginInstance[] = [CodexAuthPlugin, CopilotAuthPlugin, GitlabAuthPlugin]
 
-  const state = Instance.state(async () => {
-    const client = createOpencodeClient({
-      baseUrl: "http://localhost:4096",
-      directory: Instance.directory,
-      headers: Flag.OPENCODE_SERVER_PASSWORD
-        ? {
-            Authorization: `Basic ${Buffer.from(`${Flag.OPENCODE_SERVER_USERNAME ?? "opencode"}:${Flag.OPENCODE_SERVER_PASSWORD}`).toString("base64")}`,
-          }
-        : undefined,
-      fetch: async (...args) => Server.Default().fetch(...args),
-    })
-    const config = await Config.get()
-    const hooks: Hooks[] = []
-    const input: PluginInput = {
-      client,
-      project: Instance.project,
-      worktree: Instance.worktree,
-      directory: Instance.directory,
-      get serverUrl(): URL {
-        return Server.url ?? new URL("http://localhost:4096")
-      },
-      $: Bun.$,
-    }
+  export interface Interface {
+    readonly trigger: <
+      Name extends Exclude<keyof Required<Hooks>, "auth" | "event" | "tool">,
+      Input = Parameters<Required<Hooks>[Name]>[0],
+      Output = Parameters<Required<Hooks>[Name]>[1],
+    >(
+      name: Name,
+      input: Input,
+      output: Output,
+    ) => Effect.Effect<Output>
+    readonly list: () => Effect.Effect<Hooks[]>
+    readonly init: () => Effect.Effect<void>
+  }
 
-    for (const plugin of INTERNAL_PLUGINS) {
-      log.info("loading internal plugin", { name: plugin.name })
-      const init = await plugin(input).catch((err) => {
-        log.error("failed to load internal plugin", { name: plugin.name, error: err })
+  export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/Plugin") {}
+
+  export const layer = Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const instance = yield* InstanceContext
+      const hooks: Hooks[] = []
+
+      yield* Effect.promise(async () => {
+        const client = createOpencodeClient({
+          baseUrl: "http://localhost:4096",
+          directory: instance.directory,
+          headers: Flag.OPENCODE_SERVER_PASSWORD
+            ? {
+                Authorization: `Basic ${Buffer.from(`${Flag.OPENCODE_SERVER_USERNAME ?? "opencode"}:${Flag.OPENCODE_SERVER_PASSWORD}`).toString("base64")}`,
+              }
+            : undefined,
+          fetch: async (...args) => Server.Default().fetch(...args),
+        })
+        const config = await Config.get()
+        const input: PluginInput = {
+          client,
+          project: instance.project,
+          worktree: instance.worktree,
+          directory: instance.directory,
+          get serverUrl(): URL {
+            return Server.url ?? new URL("http://localhost:4096")
+          },
+          $: Bun.$,
+        }
+
+        for (const plugin of INTERNAL_PLUGINS) {
+          log.info("loading internal plugin", { name: plugin.name })
+          const init = await plugin(input).catch((err) => {
+            log.error("failed to load internal plugin", { name: plugin.name, error: err })
+          })
+          if (init) hooks.push(init)
+        }
+
+        let plugins = config.plugin ?? []
+        if (plugins.length) await Config.waitForDependencies()
+
+        for (let plugin of plugins) {
+          // ignore old codex plugin since it is supported first party now
+          if (plugin.includes("opencode-openai-codex-auth") || plugin.includes("opencode-copilot-auth")) continue
+          log.info("loading plugin", { path: plugin })
+          if (!plugin.startsWith("file://")) {
+            const lastAtIndex = plugin.lastIndexOf("@")
+            const pkg = lastAtIndex > 0 ? plugin.substring(0, lastAtIndex) : plugin
+            const version = lastAtIndex > 0 ? plugin.substring(lastAtIndex + 1) : "latest"
+            plugin = await BunProc.install(pkg, version).catch((err) => {
+              const cause = err instanceof Error ? err.cause : err
+              const detail = cause instanceof Error ? cause.message : String(cause ?? err)
+              log.error("failed to install plugin", { pkg, version, error: detail })
+              Bus.publish(Session.Event.Error, {
+                error: new NamedError.Unknown({
+                  message: `Failed to install plugin ${pkg}@${version}: ${detail}`,
+                }).toObject(),
+              })
+              return ""
+            })
+            if (!plugin) continue
+          }
+          // Prevent duplicate initialization when plugins export the same function
+          // as both a named export and default export (e.g., `export const X` and `export default X`).
+          // Object.entries(mod) would return both entries pointing to the same function reference.
+          await import(plugin)
+            .then(async (mod) => {
+              const seen = new Set<PluginInstance>()
+              for (const [_name, fn] of Object.entries<PluginInstance>(mod)) {
+                if (seen.has(fn)) continue
+                seen.add(fn)
+                hooks.push(await fn(input))
+              }
+            })
+            .catch((err) => {
+              const message = err instanceof Error ? err.message : String(err)
+              log.error("failed to load plugin", { path: plugin, error: message })
+              Bus.publish(Session.Event.Error, {
+                error: new NamedError.Unknown({
+                  message: `Failed to load plugin ${plugin}: ${message}`,
+                }).toObject(),
+              })
+            })
+        }
       })
-      if (init) hooks.push(init)
-    }
 
-    let plugins = config.plugin ?? []
-    if (plugins.length) await Config.waitForDependencies()
-
-    for (let plugin of plugins) {
-      // ignore old codex plugin since it is supported first party now
-      if (plugin.includes("opencode-openai-codex-auth") || plugin.includes("opencode-copilot-auth")) continue
-      log.info("loading plugin", { path: plugin })
-      if (!plugin.startsWith("file://")) {
-        const lastAtIndex = plugin.lastIndexOf("@")
-        const pkg = lastAtIndex > 0 ? plugin.substring(0, lastAtIndex) : plugin
-        const version = lastAtIndex > 0 ? plugin.substring(lastAtIndex + 1) : "latest"
-        plugin = await BunProc.install(pkg, version).catch((err) => {
-          const cause = err instanceof Error ? err.cause : err
-          const detail = cause instanceof Error ? cause.message : String(cause ?? err)
-          log.error("failed to install plugin", { pkg, version, error: detail })
-          Bus.publish(Session.Event.Error, {
-            error: new NamedError.Unknown({
-              message: `Failed to install plugin ${pkg}@${version}: ${detail}`,
-            }).toObject(),
-          })
-          return ""
-        })
-        if (!plugin) continue
-      }
-      // Prevent duplicate initialization when plugins export the same function
-      // as both a named export and default export (e.g., `export const X` and `export default X`).
-      // Object.entries(mod) would return both entries pointing to the same function reference.
-      await import(plugin)
-        .then(async (mod) => {
-          const seen = new Set<PluginInstance>()
-          for (const [_name, fn] of Object.entries<PluginInstance>(mod)) {
-            if (seen.has(fn)) continue
-            seen.add(fn)
-            hooks.push(await fn(input))
+      const trigger = Effect.fn("Plugin.trigger")(function* <
+        Name extends Exclude<keyof Required<Hooks>, "auth" | "event" | "tool">,
+        Input = Parameters<Required<Hooks>[Name]>[0],
+        Output = Parameters<Required<Hooks>[Name]>[1],
+      >(name: Name, input: Input, output: Output) {
+        if (!name) return output
+        yield* Effect.promise(async () => {
+          for (const hook of hooks) {
+            const fn = hook[name]
+            if (!fn) continue
+            // @ts-expect-error if you feel adventurous, please fix the typing, make sure to bump the try-counter if you
+            // give up.
+            // try-counter: 2
+            await fn(input, output)
           }
         })
-        .catch((err) => {
-          const message = err instanceof Error ? err.message : String(err)
-          log.error("failed to load plugin", { path: plugin, error: message })
-          Bus.publish(Session.Event.Error, {
-            error: new NamedError.Unknown({
-              message: `Failed to load plugin ${plugin}: ${message}`,
-            }).toObject(),
+        return output
+      })
+
+      const list = Effect.fn("Plugin.list")(function* () {
+        return hooks
+      })
+
+      const init = Effect.fn("Plugin.init")(function* () {
+        yield* Effect.promise(async () => {
+          const config = await Config.get()
+          for (const hook of hooks) {
+            await (hook as any).config?.(config)
+          }
+          Bus.subscribeAll(async (input) => {
+            for (const hook of hooks) {
+              hook["event"]?.({
+                event: input,
+              })
+            }
           })
         })
-    }
+      })
 
-    return {
-      hooks,
-      input,
-    }
-  })
+      return Service.of({ trigger, list, init })
+    }),
+  )
 
   export async function trigger<
     Name extends Exclude<keyof Required<Hooks>, "auth" | "event" | "tool">,
     Input = Parameters<Required<Hooks>[Name]>[0],
     Output = Parameters<Required<Hooks>[Name]>[1],
   >(name: Name, input: Input, output: Output): Promise<Output> {
-    if (!name) return output
-    for (const hook of await state().then((x) => x.hooks)) {
-      const fn = hook[name]
-      if (!fn) continue
-      // @ts-expect-error if you feel adventurous, please fix the typing, make sure to bump the try-counter if you
-      // give up.
-      // try-counter: 2
-      await fn(input, output)
-    }
-    return output
+    return runPromiseInstance(Service.use((svc) => svc.trigger(name, input, output)))
   }
 
   export async function list() {
-    return state().then((x) => x.hooks)
+    return runPromiseInstance(Service.use((svc) => svc.list()))
   }
 
   export async function init() {
-    const hooks = await state().then((x) => x.hooks)
-    const config = await Config.get()
-    for (const hook of hooks) {
-      // @ts-expect-error this is because we haven't moved plugin to sdk v2
-      await hook.config?.(config)
-    }
-    Bus.subscribeAll(async (input) => {
-      const hooks = await state().then((x) => x.hooks)
-      for (const hook of hooks) {
-        hook["event"]?.({
-          event: input,
-        })
-      }
-    })
+    return runPromiseInstance(Service.use((svc) => svc.init()))
   }
 }