fix(opencode): update Cerebras SDK reasoning replay (#34826)

Co-authored-by: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>

packages/opencode/package.json

@@ -59,7 +59,7 @@
     "@ai-sdk/amazon-bedrock": "4.0.112",
     "@ai-sdk/anthropic": "3.0.82",
     "@ai-sdk/azure": "3.0.49",
-    "@ai-sdk/cerebras": "2.0.41",
+    "@ai-sdk/cerebras": "2.0.60",
     "@ai-sdk/cohere": "3.0.27",
     "@ai-sdk/deepinfra": "2.0.41",
     "@ai-sdk/gateway": "3.0.104",

packages/opencode/test/session/llm.test.ts

@@ -832,6 +832,80 @@ describe("session.llm.stream", () => {
     },
   )
 
+  const cerebrasFixture = { providerID: "cerebras", modelID: "gpt-oss-120b" }
+  it.instance(
+    "replays Cerebras assistant reasoning using the provider-supported field",
+    () =>
+      Effect.gen(function* () {
+        const fixture = loadFixture(cerebrasFixture.providerID, cerebrasFixture.modelID)
+        const request = waitRequest(
+          "/chat/completions",
+          new Response(createChatStream("Hello"), {
+            status: 200,
+            headers: { "Content-Type": "text/event-stream" },
+          }),
+        )
+
+        const resolved = yield* Provider.use.getModel(
+          ProviderV2.ID.make(cerebrasFixture.providerID),
+          ModelV2.ID.make(fixture.model.id),
+        )
+        const sessionID = SessionID.make("session-test-cerebras-reasoning")
+        const agent = {
+          name: "test",
+          mode: "primary",
+          options: {},
+          permission: [{ permission: "*", pattern: "*", action: "allow" }],
+        } satisfies Agent.Info
+
+        const user = {
+          id: MessageID.make("msg_user-cerebras-reasoning"),
+          sessionID,
+          role: "user",
+          time: { created: Date.now() },
+          agent: agent.name,
+          model: { providerID: ProviderV2.ID.make(cerebrasFixture.providerID), modelID: resolved.id },
+        } satisfies SessionV1.User
+
+        yield* drain({
+          user,
+          sessionID,
+          model: resolved,
+          agent,
+          system: ["You are a helpful assistant."],
+          messages: [
+            { role: "user", content: "Hello" },
+            {
+              role: "assistant",
+              content: [
+                { type: "reasoning", text: "thinking" },
+                { type: "text", text: "Previous answer" },
+              ],
+            },
+            { role: "user", content: "Continue" },
+          ] satisfies ModelMessage[],
+          tools: {},
+        })
+
+        const capture = yield* Effect.promise(() => request)
+        const messages = capture.body.messages as Array<Record<string, unknown>>
+        const assistant = messages.find((msg) => msg.role === "assistant")
+
+        expect(assistant?.reasoning).toBe("thinking")
+        expect(assistant && "reasoning_content" in assistant).toBe(false)
+      }),
+    {
+      config: () => ({
+        enabled_providers: [cerebrasFixture.providerID],
+        provider: {
+          [cerebrasFixture.providerID]: {
+            options: { apiKey: "test-key", baseURL: `${state.server!.url.origin}/v1` },
+          },
+        },
+      }),
+    },
+  )
+
   const alibabaQwenFixture = { providerID: "alibaba", modelID: "qwen-plus" }
   it.instance(
     "service stream cancellation cancels provider response body promptly",