feat(core): add plugin list endpoint

Adds a plugin.list HTTP endpoint that reports currently loaded plugins, wires it through protocol, server, and generated clients, and merges it into sdk-next's plugin API. Also updates the sample plugin to register a primary agent instead of a subagent for local testing.

.opencode/plugins/sample-agent.ts

@@ -3,9 +3,9 @@ export default {
   setup: async (ctx) => {
     await ctx.agent.transform((agents) => {
       agents.update("sample-plugin-agent", (agent) => {
-        agent.description = "Example subagent registered by .opencode/plugins/sample-agent.ts"
-        agent.mode = "subagent"
-        agent.prompt = [
+        agent.description = "Example primary agent registered by .opencode/plugins/sample-agent.ts"
+        agent.mode = "primary"
+        agent.system = [
           "You are the sample plugin agent for this repository.",
           "Use this agent to verify that local plugin auto-discovery can add agents.",
           "Keep responses concise and explain which plugin registered you when asked.",

packages/client/src/generated/client.ts

@@ -4,6 +4,8 @@ import type {
   LocationGetOutput,
   AgentListInput,
   AgentListOutput,
+  PluginListInput,
+  PluginListOutput,
   SessionListInput,
   SessionListOutput,
   SessionCreateInput,
@@ -310,6 +312,20 @@ export function make(options: ClientOptions) {
           requestOptions,
         ),
     },
+    plugin: {
+      list: (input?: PluginListInput, requestOptions?: RequestOptions) =>
+        request<PluginListOutput>(
+          {
+            method: "GET",
+            path: `/api/plugin`,
+            query: { location: input?.["location"] },
+            successStatus: 200,
+            declaredStatuses: [401, 400],
+            empty: false,
+          },
+          requestOptions,
+        ),
+    },
     session: {
       list: (input?: SessionListInput, requestOptions?: RequestOptions) =>
         request<SessionListOutput>(

packages/client/src/generated/types.ts

@@ -168,6 +168,21 @@ export type AgentListOutput = {
   }>
 }
 
+export type PluginListInput = {
+  readonly location?: {
+    readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
+  }["location"]
+}
+
+export type PluginListOutput = {
+  readonly location: {
+    readonly directory: string
+    readonly workspaceID?: string
+    readonly project: { readonly id: string; readonly directory: string }
+  }
+  readonly data: ReadonlyArray<{ readonly id: string }>
+}
+
 export type SessionListInput = {
   readonly workspace?: {
     readonly workspace?: string | undefined

packages/core/src/plugin.ts

@@ -21,12 +21,15 @@ import { ToolRegistry } from "./tool/registry"
 
 export const ID = Plugin.ID
 export type ID = typeof ID.Type
+export const Info = Plugin.Info
+export type Info = Plugin.Info
 export const Event = Plugin.Event
 
 export interface Interface {
   readonly add: (id: ID, effect: PluginDefinition["effect"]) => Effect.Effect<void>
   readonly remove: (id: ID) => Effect.Effect<void>
   readonly wait: (id: ID) => Effect.Effect<void>
+  readonly list: () => Effect.Effect<Info[]>
 }
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/v2/Plugin") {}
@@ -139,6 +142,9 @@ export const layer = Layer.effect(
       add,
       remove,
       wait,
+      list: Effect.fn("Plugin.list")(function* () {
+        return Array.from(active.keys()).map((id) => ({ id }))
+      }),
     })
     host = yield* PluginHost.make(service)
     return service

packages/protocol/src/api.ts

@@ -13,6 +13,7 @@ import { SkillGroup } from "./groups/skill"
 import { EventGroup, makeEventGroup } from "./groups/event"
 import type { Definition } from "@opencode-ai/schema/event"
 import { AgentGroup } from "./groups/agent"
+import { PluginGroup } from "./groups/plugin"
 import { HealthGroup } from "./groups/health"
 import { PtyGroup } from "./groups/pty"
 import { ShellGroup } from "./groups/shell"
@@ -42,6 +43,7 @@ const makeApiFromGroup = <
     .add(HealthGroup)
     .add(LocationGroup.middleware(locationMiddleware))
     .add(AgentGroup.middleware(locationMiddleware))
+    .add(PluginGroup.middleware(locationMiddleware))
     .add(makeSessionGroup(sessionLocationMiddleware))
     .add(MessageGroup.middleware(sessionLocationMiddleware))
     .add(ModelGroup.middleware(locationMiddleware))

packages/protocol/src/client.ts

@@ -20,6 +20,7 @@ export const groupNames = {
   "server.health": "health",
   "server.location": "location",
   "server.agent": "agent",
+  "server.plugin": "plugin",
   "server.session": "session",
   "server.message": "message",
   "server.model": "model",

packages/protocol/src/groups/plugin.ts

@@ -0,0 +1,27 @@
+import { Location } from "@opencode-ai/schema/location"
+import { Plugin } from "@opencode-ai/schema/plugin"
+import { Schema } from "effect"
+import { HttpApiEndpoint, HttpApiGroup, OpenApi } from "effect/unstable/httpapi"
+import { LocationQuery, locationQueryOpenApi } from "./location"
+
+export const PluginGroup = HttpApiGroup.make("server.plugin")
+  .add(
+    HttpApiEndpoint.get("plugin.list", "/api/plugin", {
+      query: LocationQuery,
+      success: Location.response(Schema.Array(Plugin.Info)),
+    })
+      .annotateMerge(locationQueryOpenApi)
+      .annotateMerge(
+        OpenApi.annotations({
+          identifier: "v2.plugin.list",
+          summary: "List plugins",
+          description: "Retrieve currently loaded plugins.",
+        }),
+      ),
+  )
+  .annotateMerge(
+    OpenApi.annotations({
+      title: "plugins",
+      description: "Experimental plugin routes.",
+    }),
+  )

packages/schema/src/plugin.ts

@@ -6,6 +6,11 @@ import { define, inventory } from "./event"
 export const ID = Schema.String.pipe(Schema.brand("Plugin.ID"))
 export type ID = typeof ID.Type
 
+export interface Info extends Schema.Schema.Type<typeof Info> {}
+export const Info = Schema.Struct({
+  id: ID,
+}).annotate({ identifier: "Plugin.Info" })
+
 const Added = define({
   type: "plugin.added",
   schema: { id: ID },

packages/sdk-next/src/opencode.ts

@@ -44,7 +44,7 @@ export const create = Effect.fn("OpenCode.create")(function* () {
     // `PluginContext`, so `ctx.agent.transform` and every other hook behave exactly
     // as they do for a config-discovered plugin. Define agent profiles here at
     // startup, then select one per Session with `sessions.create({ agent })`.
-    plugin: plugins.register,
+    plugin: Object.assign(plugins.register, client.plugin),
   }
 })
 

packages/server/src/handlers.ts

@@ -10,6 +10,7 @@ import { CommandHandler } from "./handlers/command"
 import { SkillHandler } from "./handlers/skill"
 import { EventHandler } from "./handlers/event"
 import { AgentHandler } from "./handlers/agent"
+import { PluginHandler } from "./handlers/plugin"
 import { HealthHandler } from "./handlers/health"
 import { PtyHandler } from "./handlers/pty"
 import { ShellHandler } from "./handlers/shell"
@@ -26,6 +27,7 @@ export const handlers = Layer.mergeAll(
   HealthHandler,
   LocationHandler,
   AgentHandler,
+  PluginHandler,
   SessionHandler,
   MessageHandler,
   ModelHandler,

packages/server/src/handlers/plugin.ts

@@ -0,0 +1,13 @@
+import { PluginV2 } from "@opencode-ai/core/plugin"
+import { Effect } from "effect"
+import { HttpApiBuilder } from "effect/unstable/httpapi"
+import { Api } from "../api"
+import { response } from "../location"
+
+export const PluginHandler = HttpApiBuilder.group(Api, "server.plugin", (handlers) =>
+  handlers.handle("plugin.list", () =>
+    Effect.gen(function* () {
+      return yield* response(PluginV2.Service.use((plugin) => plugin.list()))
+    }),
+  ),
+)