feat: add gpt-5.2 support (#6698)

letta/constants.py

@@ -246,6 +246,11 @@ LLM_MAX_TOKENS = {
     "gpt-5.1-codex": 272000,
     "gpt-5.1-codex-mini": 272000,
     "gpt-5.1-codex-max": 272000,
+    # gpt-5.2
+    "gpt-5.2": 272000,
+    "gpt-5.2-2025-12-11": 272000,
+    "gpt-5.2-pro": 272000,
+    "gpt-5.2-pro-2025-12-11": 272000,
     # reasoners
     "o1": 200000,
     # "o1-pro": 200000,  # responses API only

letta/llm_api/openai_client.py

@@ -83,9 +83,9 @@ def does_not_support_minimal_reasoning(model: str) -> bool:
 def supports_none_reasoning_effort(model: str) -> bool:
     """Check if the model supports 'none' reasoning effort.
 
-    Currently, only GPT-5.1 models support the 'none' reasoning effort level.
+    Currently, GPT-5.1 and GPT-5.2 models support the 'none' reasoning effort level.
     """
-    return model.startswith("gpt-5.1")
+    return model.startswith("gpt-5.1") or model.startswith("gpt-5.2")
 
 
 def is_openai_5_model(model: str) -> bool:

letta/schemas/llm_config.py

@@ -269,6 +269,17 @@ class LLMConfig(BaseModel):
                 verbosity="medium",
                 max_tokens=16384,
             )
+        elif model_name == "gpt-5.2":
+            return cls(
+                model="gpt-5.2",
+                model_endpoint_type="openai",
+                model_endpoint="https://api.openai.com/v1",
+                model_wrapper=None,
+                context_window=272000,
+                reasoning_effort="none",  # Default to "none" for GPT-5.2
+                verbosity="medium",
+                max_tokens=16384,
+            )
         elif model_name == "letta":
             return cls(
                 model="memgpt-openai",

tests/configs/llm_model_configs/openai-gpt-5.2.json

@@ -0,0 +1,8 @@
+{
+  "context_window": 32000,
+  "model": "gpt-5.2",
+  "model_endpoint_type": "openai",
+  "model_endpoint": "https://api.openai.com/v1",
+  "model_wrapper": null,
+  "reasoning_effort": "low"
+}