diff --git a/packages/coding-agent/docs/sdk.md b/packages/coding-agent/docs/sdk.md
index f1e3885..be56106 100644
--- a/packages/coding-agent/docs/sdk.md
+++ b/packages/coding-agent/docs/sdk.md
@@ -318,7 +318,7 @@ const authStorage = AuthStorage.create();
 const modelRegistry = new ModelRegistry(authStorage);
 
 // Find specific built-in model (doesn't check if API key exists)
-const opus = getModel("anthropic", "claude-opus-4-5");
+const opus = getModel("anthropic", "claude-opus-4-6");
 if (!opus) throw new Error("Model not found");
 
 // Find any model by provider/id, including custom models from models.json
@@ -841,7 +841,7 @@ const statusTool: ToolDefinition = {
   }),
 };
 
-const model = getModel("anthropic", "claude-opus-4-5");
+const model = getModel("anthropic", "claude-opus-4-6");
 if (!model) throw new Error("Model not found");
 
 // In-memory settings with overrides
diff --git a/packages/coding-agent/src/core/model-resolver.ts b/packages/coding-agent/src/core/model-resolver.ts
index 55c656b..0279484 100644
--- a/packages/coding-agent/src/core/model-resolver.ts
+++ b/packages/coding-agent/src/core/model-resolver.ts
@@ -21,7 +21,7 @@ export const defaultModelPerProvider: Record<KnownProvider, string> = {
   anthropic: "claude-opus-4-6",
   openai: "gpt-5.4",
   "azure-openai-responses": "gpt-5.2",
-  "openai-codex": "gpt-5.4",
+  "openai-codex": "gpt-5.3-codex",
   google: "gemini-2.5-pro",
   "google-gemini-cli": "gemini-2.5-pro",
   "google-antigravity": "gemini-3.1-pro-high",
diff --git a/packages/coding-agent/src/core/sdk.ts b/packages/coding-agent/src/core/sdk.ts
index c3c5068..c0cd0e4 100644
--- a/packages/coding-agent/src/core/sdk.ts
+++ b/packages/coding-agent/src/core/sdk.ts
@@ -151,7 +151,7 @@ function getDefaultAgentDir(): string {
  * // With explicit model
  * import { getModel } from '@mariozechner/pi-ai';
  * const { session } = await createAgentSession({
- *   model: getModel('anthropic', 'claude-opus-4-5'),
+ *   model: getModel('anthropic', 'claude-opus-4-6'),
  *   thinkingLevel: 'high',
  * });
  *
diff --git a/packages/coding-agent/test/model-resolver.test.ts b/packages/coding-agent/test/model-resolver.test.ts
index 2302d40..db13769 100644
--- a/packages/coding-agent/test/model-resolver.test.ts
+++ b/packages/coding-agent/test/model-resolver.test.ts
@@ -395,9 +395,12 @@ describe("resolveCliModel", () => {
 });
 
 describe("default model selection", () => {
-  test("openai defaults are gpt-5.4", () => {
+  test("openai default stays on gpt-5.4", () => {
     expect(defaultModelPerProvider.openai).toBe("gpt-5.4");
-    expect(defaultModelPerProvider["openai-codex"]).toBe("gpt-5.4");
+  });
+
+  test("openai-codex default is gpt-5.3-codex", () => {
+    expect(defaultModelPerProvider["openai-codex"]).toBe("gpt-5.3-codex");
   });
 
   test("ai-gateway default is opus 4.6", () => {
diff --git a/packages/coding-agent/test/settings-manager.test.ts b/packages/coding-agent/test/settings-manager.test.ts
index e6ef775..4aef2e8 100644
--- a/packages/coding-agent/test/settings-manager.test.ts
+++ b/packages/coding-agent/test/settings-manager.test.ts
@@ -40,7 +40,7 @@ describe("SettingsManager", () => {
 
       // Simulate user editing settings.json externally to add enabledModels
       const currentSettings = JSON.parse(readFileSync(settingsPath, "utf-8"));
-      currentSettings.enabledModels = ["claude-opus-4-5", "gpt-5.2-codex"];
+      currentSettings.enabledModels = ["claude-opus-4-6", "gpt-5.3-codex"];
       writeFileSync(settingsPath, JSON.stringify(currentSettings, null, 2));
 
       // User changes thinking level via Shift+Tab
@@ -50,8 +50,8 @@ describe("SettingsManager", () => {
       // Verify enabledModels is preserved
       const savedSettings = JSON.parse(readFileSync(settingsPath, "utf-8"));
       expect(savedSettings.enabledModels).toEqual([
-        "claude-opus-4-5",
-        "gpt-5.2-codex",
+        "claude-opus-4-6",
+        "gpt-5.3-codex",
       ]);
       expect(savedSettings.defaultThinkingLevel).toBe("high");
       expect(savedSettings.theme).toBe("dark");