Agents: allow gpt-5.3-codex-spark in fallback and thinking (#14990)

* Agents: allow gpt-5.3-codex-spark in fallback and thinking

* Fix: model picker issue for openai-codex/gpt-5.3-codex-spark

Fixed an issue in the model picker.

src/agents/pi-embedded-runner/model.test.ts

@@ -172,6 +172,43 @@ describe("resolveModel", () => {
     });
   });
 
+  it("builds an openai-codex fallback for gpt-5.3-codex-spark", () => {
+    const templateModel = {
+      id: "gpt-5.2-codex",
+      name: "GPT-5.2 Codex",
+      provider: "openai-codex",
+      api: "openai-codex-responses",
+      baseUrl: "https://chatgpt.com/backend-api",
+      reasoning: true,
+      input: ["text", "image"] as const,
+      cost: { input: 1.75, output: 14, cacheRead: 0.175, cacheWrite: 0 },
+      contextWindow: 272000,
+      maxTokens: 128000,
+    };
+
+    vi.mocked(discoverModels).mockReturnValue({
+      find: vi.fn((provider: string, modelId: string) => {
+        if (provider === "openai-codex" && modelId === "gpt-5.2-codex") {
+          return templateModel;
+        }
+        return null;
+      }),
+    } as unknown as ReturnType<typeof discoverModels>);
+
+    const result = resolveModel("openai-codex", "gpt-5.3-codex-spark", "/tmp/agent");
+
+    expect(result.error).toBeUndefined();
+    expect(result.model).toMatchObject({
+      provider: "openai-codex",
+      id: "gpt-5.3-codex-spark",
+      api: "openai-codex-responses",
+      baseUrl: "https://chatgpt.com/backend-api",
+      reasoning: true,
+      contextWindow: 272000,
+      maxTokens: 128000,
+    });
+  });
+
   it("builds an anthropic forward-compat fallback for claude-opus-4-6", () => {
     const templateModel = {
       id: "claude-opus-4-5",
@@ -283,6 +320,12 @@ describe("resolveModel", () => {
     expect(result.error).toBe("Unknown model: openai-codex/gpt-4.1-mini");
   });
 
+  it("errors for unknown gpt-5.3-codex-* variants", () => {
+    const result = resolveModel("openai-codex", "gpt-5.3-codex-unknown", "/tmp/agent");
+    expect(result.model).toBeUndefined();
+    expect(result.error).toBe("Unknown model: openai-codex/gpt-5.3-codex-unknown");
+  });
+
   it("uses codex fallback even when openai-codex provider is configured", () => {
     // This test verifies the ordering: codex fallback must fire BEFORE the generic providerCfg fallback.
     // If ordering is wrong, the generic fallback would use api: "openai-responses" (the default)

src/agents/pi-embedded-runner/model.ts

@@ -20,6 +20,7 @@ type InlineProviderConfig = {
 };
 
 const OPENAI_CODEX_GPT_53_MODEL_ID = "gpt-5.3-codex";
+const OPENAI_CODEX_GPT_53_SPARK_MODEL_ID = "gpt-5.3-codex-spark";
 
 const OPENAI_CODEX_TEMPLATE_MODEL_IDS = ["gpt-5.2-codex"] as const;
 
@@ -39,7 +40,11 @@ function resolveOpenAICodexGpt53FallbackModel(
   if (normalizedProvider !== "openai-codex") {
     return undefined;
   }
-  if (trimmedModelId.toLowerCase() !== OPENAI_CODEX_GPT_53_MODEL_ID) {
+  const loweredModelId = trimmedModelId.toLowerCase();
+  if (
+    loweredModelId !== OPENAI_CODEX_GPT_53_MODEL_ID &&
+    loweredModelId !== OPENAI_CODEX_GPT_53_SPARK_MODEL_ID
+  ) {
     return undefined;
   }