diff --git a/electron/services/providers/provider-runtime-sync.ts b/electron/services/providers/provider-runtime-sync.ts
index eeb5d2d8..19c1e891 100644
--- a/electron/services/providers/provider-runtime-sync.ts
+++ b/electron/services/providers/provider-runtime-sync.ts
@@ -30,7 +30,7 @@ import { listAgentsSnapshot } from '../../utils/agent-config';
 
 /** OpenClaw Codex OAuth hooks only apply to the canonical `openai` provider id. */
 const OPENAI_OAUTH_RUNTIME_PROVIDER = 'openai';
-const OPENAI_OAUTH_DEFAULT_MODEL_REF = `${OPENAI_OAUTH_RUNTIME_PROVIDER}/gpt-5.5`;
+const OPENAI_OAUTH_DEFAULT_MODEL_REF = `${OPENAI_OAUTH_RUNTIME_PROVIDER}/gpt-5.6-sol`;
 
 /**
  * Provider types that are not in the built-in provider registry (no `providerConfig.api`).
diff --git a/electron/shared/providers/registry.ts b/electron/shared/providers/registry.ts
index 1b60bbad..90cae87e 100644
--- a/electron/shared/providers/registry.ts
+++ b/electron/shared/providers/registry.ts
@@ -31,11 +31,11 @@ export const PROVIDER_DEFINITIONS: ProviderDefinition[] = [
     requiresApiKey: true,
     category: 'official',
     envVar: 'OPENAI_API_KEY',
-    defaultModelId: 'gpt-5.5',
+    defaultModelId: 'gpt-5.6-sol',
     isOAuth: true,
     supportsApiKey: true,
     showModelId: true,
-    modelIdPlaceholder: 'gpt-5.5',
+    modelIdPlaceholder: 'gpt-5.6-sol',
     supportedAuthModes: ['api_key', 'oauth_browser'],
     defaultAuthMode: 'api_key',
     supportsMultipleAccounts: true,
diff --git a/electron/utils/browser-oauth.ts b/electron/utils/browser-oauth.ts
index 95d3e9de..6b89355c 100644
--- a/electron/utils/browser-oauth.ts
+++ b/electron/utils/browser-oauth.ts
@@ -19,7 +19,7 @@ import {
 export type BrowserOAuthProviderType = 'openai';
 
 const OPENAI_RUNTIME_PROVIDER_ID = 'openai';
-const OPENAI_OAUTH_DEFAULT_MODEL = 'gpt-5.5';
+const OPENAI_OAUTH_DEFAULT_MODEL = 'gpt-5.6-sol';
 
 class BrowserOAuthManager extends EventEmitter {
   private activeAccountId: string | null = null;
diff --git a/src/lib/providers.ts b/src/lib/providers.ts
index 20c3f246..548aa3ed 100644
--- a/src/lib/providers.ts
+++ b/src/lib/providers.ts
@@ -172,9 +172,9 @@ export const PROVIDER_TYPE_INFO: ProviderTypeInfo[] = [
     requiresApiKey: true,
     isOAuth: true,
     supportsApiKey: true,
-    defaultModelId: 'gpt-5.5',
+    defaultModelId: 'gpt-5.6-sol',
     showModelId: true,
-    modelIdPlaceholder: 'gpt-5.5',
+    modelIdPlaceholder: 'gpt-5.6-sol',
     apiKeyUrl: 'https://platform.openai.com/api-keys',
   },
   {
diff --git a/tests/unit/provider-runtime-sync.test.ts b/tests/unit/provider-runtime-sync.test.ts
index 93158cb4..baecc972 100644
--- a/tests/unit/provider-runtime-sync.test.ts
+++ b/tests/unit/provider-runtime-sync.test.ts
@@ -234,7 +234,7 @@ describe('provider-runtime-sync refresh strategy', () => {
     expect(gateway.debouncedRestart).not.toHaveBeenCalled();
   });
 
-  it('uses gpt-5.5 as the browser OAuth default model for OpenAI', async () => {
+  it('uses gpt-5.6-sol as the browser OAuth default model for OpenAI', async () => {
     mocks.getProvider.mockResolvedValue(
       createProvider({
         id: 'openai-personal',
@@ -257,7 +257,7 @@ describe('provider-runtime-sync refresh strategy', () => {
 
     expect(mocks.setOpenClawDefaultModelWithOverride).toHaveBeenCalledWith(
       'openai',
-      'openai/gpt-5.5',
+      'openai/gpt-5.6-sol',
       {
         baseUrl: 'https://chatgpt.com/backend-api/codex',
         api: 'openai-chatgpt-responses',
diff --git a/tests/unit/providers.test.ts b/tests/unit/providers.test.ts
index 2ae8be6b..0fc02878 100644
--- a/tests/unit/providers.test.ts
+++ b/tests/unit/providers.test.ts
@@ -201,7 +201,7 @@ describe('provider metadata', () => {
 
     expect(openai).toMatchObject({
       showModelId: true,
-      defaultModelId: 'gpt-5.5',
+      defaultModelId: 'gpt-5.6-sol',
       isOAuth: true,
       supportsApiKey: true,
     });
@@ -216,7 +216,7 @@ describe('provider metadata', () => {
       expect(shouldShowProviderModelId(provider, true)).toBe(true);
     }
 
-    expect(resolveProviderModelForSave(openai, '   ', false)).toBe('gpt-5.5');
+    expect(resolveProviderModelForSave(openai, '   ', false)).toBe('gpt-5.6-sol');
     expect(resolveProviderModelForSave(google, '   ', false)).toBe('gemini-3.1-pro-preview');
     expect(resolveProviderModelForSave(minimax, '   ', false)).toBe('MiniMax-M3');
     expect(resolveProviderModelForSave(minimaxCn, '   ', false)).toBe('MiniMax-M3');