fix(cli): wait for consistent ACP model choices (#46613)

packages/cli/src/acp/service.ts

@@ -412,7 +412,11 @@ async function loadCatalog(client: OpenCodeClient, cwd: string): Promise<Catalog
       client.skill.list({ location }),
     ])
     const models = modelResult.data.filter((model) => model.enabled)
-    const defaultModel = defaultResult.data ?? models[0]
+    const preferred = defaultResult.data
+    // Parallel reads can straddle initialization; select only from this model list.
+    const defaultModel = preferred
+      ? models.find((model) => model.providerID === preferred.providerID && model.id === preferred.id)
+      : models[0]
     const agents = agentResult.data.filter((agent) => agent.mode !== "subagent" && !agent.hidden)
     const defaultAgent = agents.find((agent) => agent.mode === "primary") ?? agents[0]
     if (defaultModel && defaultAgent) {

packages/cli/test/acp/service-directory.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, test } from "bun:test"
 import type { McpServer, SessionConfigOption } from "@agentclientprotocol/sdk"
 import { makeACPFixture, makeSession, secondModel } from "./service-fixture"
+import { flattenSelectOptions, requireSelectOption } from "./subprocess"
 
 describe("acp service directory behavior", () => {
   test("creates sessions from a catalog shared by concurrent callers in the same cwd", async () => {
@@ -72,6 +73,41 @@ describe("acp service directory behavior", () => {
     ])
   })
 
+  test.each(["empty", "missing the default"])(
+    "retries when the model list is %s but the default is ready",
+    async (initial) => {
+      await using fixture = makeACPFixture({
+        fetch(request, context) {
+          if (
+            request.path === "/api/model" &&
+            context.requests.filter((request) => request.path === "/api/model").length === 1
+          ) {
+            return Response.json({
+              location: {
+                directory: "/workspace",
+                project: { id: "global", directory: "/workspace", canonical: "/workspace" },
+              },
+              data: initial === "empty" ? [] : [secondModel],
+            })
+          }
+          if (request.method === "POST" && request.path === "/api/session") {
+            return Response.json({ data: makeSession("ses_ready") })
+          }
+          return undefined
+        },
+      })
+
+      const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+      const model = requireSelectOption(session.configOptions, "model")
+      const choices = flattenSelectOptions(model).map((option) => option.value)
+
+      expect(choices).toContain("test/second-model")
+      expect(choices).toContain("test/test-model")
+      expect(model.currentValue).toBe("test/test-model")
+      expect(fixture.requests.filter((request) => request.path === "/api/model")).toHaveLength(2)
+    },
+  )
+
   test("does not cache a failed catalog load", async () => {
     let modelCalls = 0
     await using fixture = makeACPFixture({