fix codex context window and add a few tests

packages/ai/src/models.generated.ts

@@ -2287,6 +2287,23 @@ export const MODELS = {
 			contextWindow: 128000,
 			maxTokens: 32000,
 		} satisfies Model<"azure-openai-responses">,
+		"gpt-5.4": {
+			id: "gpt-5.4",
+			name: "GPT-5.4",
+			api: "azure-openai-responses",
+			provider: "azure-openai-responses",
+			baseUrl: "",
+			reasoning: true,
+			input: ["text", "image"],
+			cost: {
+				input: 2.5,
+				output: 15,
+				cacheRead: 0.25,
+				cacheWrite: 0,
+			},
+			contextWindow: 272000,
+			maxTokens: 128000,
+		} satisfies Model<"azure-openai-responses">,
 		"o1": {
 			id: "o1",
 			name: "o1",
@@ -5420,6 +5437,23 @@ export const MODELS = {
 			contextWindow: 128000,
 			maxTokens: 32000,
 		} satisfies Model<"openai-responses">,
+		"gpt-5.4": {
+			id: "gpt-5.4",
+			name: "GPT-5.4",
+			api: "openai-responses",
+			provider: "openai",
+			baseUrl: "https://api.openai.com/v1",
+			reasoning: true,
+			input: ["text", "image"],
+			cost: {
+				input: 2.5,
+				output: 15,
+				cacheRead: 0.25,
+				cacheWrite: 0,
+			},
+			contextWindow: 272000,
+			maxTokens: 128000,
+		} satisfies Model<"openai-responses">,
 		"o1": {
 			id: "o1",
 			name: "o1",
@@ -5677,6 +5711,23 @@ export const MODELS = {
 			contextWindow: 128000,
 			maxTokens: 128000,
 		} satisfies Model<"openai-codex-responses">,
+		"gpt-5.4": {
+			id: "gpt-5.4",
+			name: "GPT-5.4",
+			api: "openai-codex-responses",
+			provider: "openai-codex",
+			baseUrl: "https://chatgpt.com/backend-api",
+			reasoning: true,
+			input: ["text", "image"],
+			cost: {
+				input: 2.5,
+				output: 15,
+				cacheRead: 0.25,
+				cacheWrite: 0,
+			},
+			contextWindow: 272000,
+			maxTokens: 128000,
+		} satisfies Model<"openai-codex-responses">,
 	},
 	"opencode": {
 		"big-pickle": {
@@ -6104,6 +6155,23 @@ export const MODELS = {
 			contextWindow: 400000,
 			maxTokens: 128000,
 		} satisfies Model<"openai-responses">,
+		"gpt-5.3-codex-spark": {
+			id: "gpt-5.3-codex-spark",
+			name: "GPT-5.3 Codex Spark",
+			api: "openai-responses",
+			provider: "opencode",
+			baseUrl: "https://opencode.ai/zen/v1",
+			reasoning: true,
+			input: ["text"],
+			cost: {
+				input: 1.75,
+				output: 14,
+				cacheRead: 0.175,
+				cacheWrite: 0,
+			},
+			contextWindow: 128000,
+			maxTokens: 128000,
+		} satisfies Model<"openai-responses">,
 		"gpt-5.4": {
 			id: "gpt-5.4",
 			name: "GPT-5.4",
@@ -6118,7 +6186,7 @@ export const MODELS = {
 				cacheRead: 0.25,
 				cacheWrite: 0,
 			},
-			contextWindow: 1050000,
+			contextWindow: 272000,
 			maxTokens: 128000,
 		} satisfies Model<"openai-responses">,
 		"kimi-k2.5": {
@@ -7987,13 +8055,13 @@ export const MODELS = {
 			reasoning: true,
 			input: ["text", "image"],
 			cost: {
-				input: 0.41,
+				input: 0.44999999999999996,
-				output: 2.06,
+				output: 2.2,
-				cacheRead: 0.07,
+				cacheRead: 0.22499999999999998,
 				cacheWrite: 0,
 			},
 			contextWindow: 262144,
-			maxTokens: 4096,
+			maxTokens: 65535,
 		} satisfies Model<"openai-completions">,
 		"nex-agi/deepseek-v3.1-nex-n1": {
 			id: "nex-agi/deepseek-v3.1-nex-n1",
@@ -10333,9 +10401,9 @@ export const MODELS = {
 			reasoning: true,
 			input: ["text"],
 			cost: {
-				input: 0.6,
+				input: 0.7999999999999999,
-				output: 1.9,
+				output: 2.56,
-				cacheRead: 0.119,
+				cacheRead: 0.16,
 				cacheWrite: 0,
 			},
 			contextWindow: 202752,

packages/ai/test/openai-codex-stream.test.ts

@@ -231,7 +231,7 @@ describe("openai-codex streaming", () => {
 		await streamResult.result();
 	});
 
-	it("clamps gpt-5.3-codex minimal reasoning effort to low", async () => {
+	it.each(["gpt-5.3-codex", "gpt-5.4"])("clamps %s minimal reasoning effort to low", async (modelId) => {
 		const tempDir = mkdtempSync(join(tmpdir(), "pi-codex-stream-"));
 		process.env.PI_CODING_AGENT_DIR = tempDir;
 
@@ -303,8 +303,8 @@ describe("openai-codex streaming", () => {
 		global.fetch = fetchMock as typeof fetch;
 
 		const model: Model<"openai-codex-responses"> = {
-			id: "gpt-5.3-codex",
+			id: modelId,
-			name: "GPT-5.3 Codex",
+			name: modelId,
 			api: "openai-codex-responses",
 			provider: "openai-codex",
 			baseUrl: "https://chatgpt.com/backend-api",

packages/ai/test/supports-xhigh.test.ts

@@ -14,6 +14,12 @@ describe("supportsXhigh", () => {
 		expect(supportsXhigh(model!)).toBe(false);
 	});
 
+	it("returns true for GPT-5.4 models", () => {
+		const model = getModel("openai-codex", "gpt-5.4");
+		expect(model).toBeDefined();
+		expect(supportsXhigh(model!)).toBe(true);
+	});
+
 	it("returns false for OpenRouter Opus 4.6 (openai-completions API)", () => {
 		const model = getModel("openrouter", "anthropic/claude-opus-4.6");
 		expect(model).toBeDefined();

packages/coding-agent/test/model-resolver.test.ts

@@ -373,6 +373,11 @@ describe("resolveCliModel", () => {
 });
 
 describe("default model selection", () => {
+	test("openai defaults are gpt-5.4", () => {
+		expect(defaultModelPerProvider.openai).toBe("gpt-5.4");
+		expect(defaultModelPerProvider["openai-codex"]).toBe("gpt-5.4");
+	});
+
 	test("ai-gateway default is opus 4.6", () => {
 		expect(defaultModelPerProvider["vercel-ai-gateway"]).toBe("anthropic/claude-opus-4-6");
 	});