fix: surface GPT-5.3 Codex for ChatGPT OAuth providers (#9379)

letta/schemas/providers/chatgpt_oauth.py

@@ -36,6 +36,8 @@ TOKEN_REFRESH_BUFFER_SECONDS = 300
 # Model list based on opencode-openai-codex-auth plugin presets
 # Reasoning effort levels are configured via llm_config.reasoning_effort
 CHATGPT_MODELS = [
+    # GPT-5.3 codex
+    {"name": "gpt-5.3-codex", "context_window": 272000},
     # GPT-5.2 models (supports none/low/medium/high/xhigh reasoning)
     {"name": "gpt-5.2", "context_window": 272000},
     {"name": "gpt-5.2-codex", "context_window": 272000},

letta/server/server.py

@@ -1333,8 +1333,31 @@ class SyncServer(object):
                     # Get typed provider to access schema defaults (e.g., base_url)
                     typed_provider = provider.cast_to_subtype()
 
-                    # Sync models if not synced yet
-                    if provider.last_synced is None:
+                    provider_llm_models = None
+                    should_sync_models = provider.last_synced is None
+
+                    # ChatGPT OAuth uses a hardcoded model list. If that list changes,
+                    # backfill already-synced providers that are missing new handles.
+                    if (
+                        provider.provider_type == ProviderType.chatgpt_oauth
+                        and not should_sync_models
+                    ):
+                        expected_models = await typed_provider.list_llm_models_async()
+                        expected_handles = {model.handle for model in expected_models}
+                        provider_llm_models = await self.provider_manager.list_models_async(
+                            actor=actor,
+                            model_type="llm",
+                            provider_id=provider.id,
+                            enabled=True,
+                        )
+                        existing_handles = {
+                            model.handle for model in provider_llm_models
+                        }
+                        should_sync_models = not expected_handles.issubset(
+                            existing_handles
+                        )
+
+                    if should_sync_models:
                         models = await typed_provider.list_llm_models_async()
                         embedding_models = await typed_provider.list_embedding_models_async()
                         await self.provider_manager.sync_provider_models_async(
@@ -1346,12 +1369,13 @@ class SyncServer(object):
                         await self.provider_manager.update_provider_last_synced_async(provider.id, actor=actor)
 
                     # Read from database
-                    provider_llm_models = await self.provider_manager.list_models_async(
-                        actor=actor,
-                        model_type="llm",
-                        provider_id=provider.id,
-                        enabled=True,
-                    )
+                    if provider_llm_models is None:
+                        provider_llm_models = await self.provider_manager.list_models_async(
+                            actor=actor,
+                            model_type="llm",
+                            provider_id=provider.id,
+                            enabled=True,
+                        )
                     for model in provider_llm_models:
                         llm_config = LLMConfig(
                             model=model.name,

tests/test_providers.py

@@ -19,10 +19,16 @@ from letta.schemas.providers import (
     VLLMProvider,
     ZAIProvider,
 )
+from letta.schemas.providers.chatgpt_oauth import CHATGPT_MODELS
 from letta.schemas.secret import Secret
 from letta.settings import model_settings
 
 
+def test_chatgpt_oauth_model_allowlist_includes_gpt_5_3_codex():
+    model_names = {model["name"] for model in CHATGPT_MODELS}
+    assert "gpt-5.3-codex" in model_names
+
+
 def test_openai():
     provider = OpenAIProvider(
         name="openai",

tests/test_server_providers.py

@@ -1,5 +1,6 @@
 """Tests for provider initialization via ProviderManager.sync_base_providers and provider model persistence."""
 
+import json
 import uuid
 from unittest.mock import AsyncMock, MagicMock, patch
 
@@ -2660,6 +2661,70 @@ async def test_byok_provider_last_synced_skips_sync_when_set(default_user, provi
     assert f"test-byok-cached-{test_id}/gpt-4o" in byok_handles
 
 
+@pytest.mark.asyncio
+async def test_chatgpt_oauth_byok_resyncs_when_allowlist_expands(
+    default_user, provider_manager
+):
+    """ChatGPT OAuth providers should backfill newly added hardcoded models."""
+    test_id = generate_test_id()
+    provider_name = f"test-chatgpt-oauth-{test_id}"
+
+    oauth_credentials = json.dumps(
+        {
+            "access_token": "test-access-token",
+            "refresh_token": "test-refresh-token",
+            "account_id": "test-account-id",
+            "expires_at": 4_102_444_800,  # year 2100 (seconds)
+        }
+    )
+
+    byok_provider = await provider_manager.create_provider_async(
+        ProviderCreate(
+            name=provider_name,
+            provider_type=ProviderType.chatgpt_oauth,
+            api_key=oauth_credentials,
+        ),
+        actor=default_user,
+        is_byok=True,
+    )
+
+    # Simulate a stale provider model cache that predates gpt-5.3-codex.
+    stale_models = [
+        LLMConfig(
+            model="gpt-5.2-codex",
+            model_endpoint_type="chatgpt_oauth",
+            model_endpoint="https://chatgpt.com/backend-api/codex/responses",
+            context_window=272000,
+            handle=f"{provider_name}/gpt-5.2-codex",
+            provider_name=provider_name,
+            provider_category=ProviderCategory.byok,
+        )
+    ]
+    await provider_manager.sync_provider_models_async(
+        provider=byok_provider,
+        llm_models=stale_models,
+        embedding_models=[],
+        organization_id=default_user.organization_id,
+    )
+    await provider_manager.update_provider_last_synced_async(
+        byok_provider.id, actor=default_user
+    )
+
+    server = SyncServer(init_with_default_org_and_user=False)
+    server.default_user = default_user
+    server.provider_manager = provider_manager
+    server._enabled_providers = []
+
+    byok_models = await server.list_llm_models_async(
+        actor=default_user,
+        provider_category=[ProviderCategory.byok],
+        provider_name=provider_name,
+    )
+
+    byok_handles = {model.handle for model in byok_models}
+    assert f"{provider_name}/gpt-5.3-codex" in byok_handles
+
+
 @pytest.mark.asyncio
 async def test_base_provider_updates_last_synced_on_sync(default_user, provider_manager):
     """Test that base provider sync updates the last_synced timestamp."""