diff --git a/src/server/__tests__/providers.test.ts b/src/server/__tests__/providers.test.ts
index 23bc26c6..8d01edf7 100644
--- a/src/server/__tests__/providers.test.ts
+++ b/src/server/__tests__/providers.test.ts
@@ -313,6 +313,18 @@ describe('ProviderService', () => {
           },
         })
       })
+
+      test('activating ChatGPT Official only persists activeId for Task 1', async () => {
+        const svc = new ProviderService()
+
+        await svc.activateProvider('openai-official')
+
+        const config = await readProvidersConfig()
+        expect(config.activeId).toBe('openai-official')
+        await expect(
+          fs.readFile(path.join(tmpDir, 'cc-haha', 'settings.json'), 'utf-8'),
+        ).rejects.toThrow()
+      })
     })
 
     test('should throw 404 for non-existent id', async () => {
@@ -740,6 +752,14 @@ describe('ProviderService', () => {
       expect(active).toBeNull()
     })
 
+    test('should return null for explicit ChatGPT Official proxy lookup', async () => {
+      const svc = new ProviderService()
+
+      const active = await svc.getProviderForProxy('openai-official')
+
+      expect(active).toBeNull()
+    })
+
     test('should return the active provider proxy config', async () => {
       const svc = new ProviderService()
       const provider = await svc.addProvider(sampleInput())
@@ -751,6 +771,15 @@ describe('ProviderService', () => {
       expect(active!.apiKey).toBe(provider.apiKey)
       expect(active!.apiFormat).toBe('anthropic')
     })
+
+    test('should return null when ChatGPT Official is the active provider', async () => {
+      const svc = new ProviderService()
+      await svc.activateProvider('openai-official')
+
+      const active = await svc.getProviderForProxy()
+
+      expect(active).toBeNull()
+    })
   })
 
   describe('testProvider', () => {
diff --git a/src/server/services/providerService.ts b/src/server/services/providerService.ts
index a9783bfd..cc0fba8e 100644
--- a/src/server/services/providerService.ts
+++ b/src/server/services/providerService.ts
@@ -358,6 +358,10 @@ export class ProviderService {
     index.activeId = id
     await this.writeIndex(index)
 
+    if (isOpenAIOfficialProviderId(id)) {
+      return
+    }
+
     if (provider.presetId === 'official') {
       await this.clearProviderFromSettings()
     } else {
@@ -418,6 +422,12 @@ export class ProviderService {
   }
 
   async getProviderRuntimeEnv(id: string): Promise<Record<string, string>> {
+    if (isOpenAIOfficialProviderId(id)) {
+      // Task 1 only persists the built-in provider selection. Task 3 wires the
+      // dedicated OAuth runtime env for ChatGPT Official sessions.
+      return {}
+    }
+
     const provider = await this.getProvider(id)
     return this.buildManagedEnv(provider, {
       proxyPath: `/proxy/providers/${provider.id}`,
@@ -528,6 +538,9 @@ export class ProviderService {
     apiFormat: ApiFormat
   } | null> {
     if (providerId) {
+      if (isOpenAIOfficialProviderId(providerId)) {
+        return null
+      }
       const provider = await this.getProvider(providerId)
       return {
         baseUrl: provider.baseUrl,
@@ -538,6 +551,9 @@ export class ProviderService {
 
     const index = await this.readIndex()
     if (!index.activeId) return null
+    if (isOpenAIOfficialProviderId(index.activeId)) {
+      return null
+    }
     const provider = await this.getProvider(index.activeId).catch(() => null)
     if (!provider) return null
     return {