fix(acp): wait for a cold location's plugins before the first catalog read

packages/cli/src/acp/catalog.ts

@@ -124,15 +124,17 @@ export const make = Effect.fnUntraced(function* (client: OpenCodeClient) {
   } satisfies Interface
 })
 
-const load = (client: OpenCodeClient, cwd: string) =>
-  read(client, cwd).pipe(
-    // Providers may still be discovering models after startup.
-    Effect.retry({
-      while: (error) => error._tag === "ACPCatalogNotReadyError",
-      schedule: Schedule.spaced("25 millis").pipe(Schedule.upTo({ duration: "5 seconds" })),
-    }),
-    Effect.withSpan("cli.acp.catalog.load"),
+const poll = Schedule.spaced("25 millis").pipe(Schedule.upTo({ duration: "5 seconds" }))
+
+// A cold Location lists no plugins until activation finishes, and providers may still discover models after that.
+const load = Effect.fn("cli.acp.catalog.load")(function* (client: OpenCodeClient, cwd: string) {
+  yield* client.plugin
+    .list({ location: { directory: cwd } })
+    .pipe(Effect.repeat({ until: (plugins) => plugins.data.length > 0, schedule: poll }), Effect.ignore)
+  return yield* read(client, cwd).pipe(
+    Effect.retry({ while: (error) => error._tag === "ACPCatalogNotReadyError", schedule: poll }),
   )
+})
 
 const read = Effect.fnUntraced(function* (client: OpenCodeClient, cwd: string) {
   const location = { directory: cwd }

packages/cli/test/acp/catalog.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test } from "bun:test"
 import { currentValue } from "./select-options"
-import { rpcError, secondModel, startSession } from "./wire-fixture"
+import { rpcError, secondModel, startSession, startWire } from "./wire-fixture"
 
 describe("acp catalog and config options over the wire", () => {
   test("switches model, effort, and mode against the warm catalog", async () => {
@@ -33,4 +33,34 @@ describe("acp catalog and config options over the wire", () => {
       data: { modelId: "test/missing-model" },
     })
   })
+
+  test("answers the first session after a cold location activates its plugins (#52729, #52472)", async () => {
+    await using acp = await startWire()
+    const plugins = acp.server.catalog.plugins.splice(0)
+    acp.server.catalog.models.splice(1)
+    await acp.initialize()
+    const activated = Bun.sleep(200).then(() => {
+      acp.server.catalog.plugins.push(...plugins)
+      acp.server.catalog.models.push(secondModel)
+    })
+
+    const session = await acp.newSession()
+    const selected = await acp.request("session/set_config_option", {
+      sessionId: session.sessionId,
+      configId: "model",
+      value: "test/second-model",
+    })
+    await activated
+
+    expect(session.configOptions).toContainEqual(
+      expect.objectContaining({
+        id: "model",
+        options: [
+          { value: "test/second-model", name: "test/Second Model" },
+          { value: "test/test-model", name: "test/Test Model" },
+        ],
+      }),
+    )
+    expect(currentValue(selected, "model")).toBe("test/second-model")
+  })
 })

packages/cli/test/acp/wire-fixture.ts

@@ -24,6 +24,7 @@ import type { Command } from "@opencode/schema/command"
 import { Form } from "@opencode/schema/form"
 import type { Location } from "@opencode/schema/location"
 import type { Model } from "@opencode/schema/model"
+import type { Plugin } from "@opencode/schema/plugin"
 import type { Session } from "@opencode/schema/session"
 import type { SessionMessage } from "@opencode/schema/session-message"
 import type { TokenUsage } from "@opencode/schema/token-usage"
@@ -40,6 +41,7 @@ type CommandInfo = typeof Command.Info.Encoded
 type LocationRef = typeof Location.PublicRef.Encoded
 type ModelInfo = typeof Model.Info.Encoded
 type ModelRef = typeof Model.Ref.Encoded
+type PluginInfo = typeof Plugin.Info.Encoded
 type SessionInfo = typeof Session.Info.Encoded
 type SessionMessageInfo = typeof SessionMessage.Info.Encoded
 type TokenUsageInfo = typeof TokenUsage.Info.Encoded
@@ -155,6 +157,7 @@ type Catalog = {
   models: ModelInfo[]
   agents: AgentInfo[]
   commands: CommandInfo[]
+  plugins: PluginInfo[]
 }
 
 export type InitializeOptions = {
@@ -559,6 +562,14 @@ function startServer(options: WireOptions, changed: () => void) {
     models: [testModel, secondModel],
     agents: [buildAgent, planAgent],
     commands: [reviewCommand],
+    plugins: [
+      {
+        id: "opencode.models.dev",
+        source: { type: "builtin" },
+        features: { server: true },
+        state: { status: "active" },
+      },
+    ],
   }
   const requests: ServerRequest[] = []
   const submissions: Submission[] = []
@@ -697,6 +708,7 @@ function startServer(options: WireOptions, changed: () => void) {
       "/api/model/default": { GET: catalogRoute(() => catalog.models[0] ?? null) },
       "/api/agent": { GET: catalogRoute(() => catalog.agents) },
       "/api/command": { GET: catalogRoute(() => catalog.commands) },
+      "/api/plugin": { GET: catalogRoute(() => catalog.plugins) },
       "/api/session": {
         GET: route((_req, query) => {
           const sessions = [...fake.sessions.values()]