fix(ai): record an integer $ai_http_status in the LangChain callback handler

.sampo/changesets/langchain-http-status-int.md

@@ -0,0 +1,5 @@
+---
+pypi/posthog: patch
+---
+
+The LangChain callback handler now records `$ai_http_status` as an integer for failed generations. An error that carries a string `code` and no status code (such as OpenAI's `rate_limit_exceeded`) gave a string status; it now gives `0`, as an error without a status already did.

posthog/ai/langchain/callbacks.py

@@ -1036,8 +1036,12 @@ def _get_http_status(error: BaseException) -> int:
     # OpenAI: https://github.com/openai/openai-python/blob/main/src/openai/_exceptions.py
     # Anthropic: https://github.com/anthropics/anthropic-sdk-python/blob/main/src/anthropic/_exceptions.py
     # Google: https://github.com/googleapis/python-api-core/blob/main/google/api_core/exceptions.py
-    status_code = getattr(error, "status_code", getattr(error, "code", 0))
-    return status_code
+    # `code` is a string on some errors (OpenAI's "rate_limit_exceeded"), so only ints count
+    for attribute in ("status_code", "code"):
+        value = getattr(error, attribute, None)
+        if isinstance(value, int) and not isinstance(value, bool):
+            return value
+    return 0
 
 
 def _get_langchain_run_name(

posthog/test/ai/langchain/test_callbacks.py

@@ -2953,3 +2953,64 @@ def test_stop_reason_resolution(
 
     props = mock_client.capture.call_args.kwargs["properties"]
     assert props.get("$ai_stop_reason") == expected
+
+
+class TestGetHttpStatus:
+    def test_uses_the_status_code_of_an_http_error(self):
+        from posthog.ai.langchain.callbacks import _get_http_status
+
+        error = Exception("rate limited")
+        error.status_code = 429  # type: ignore[attr-defined]
+
+        assert _get_http_status(error) == 429
+
+    def test_uses_an_integer_code_when_there_is_no_status_code(self):
+        from posthog.ai.langchain.callbacks import _get_http_status
+
+        error = Exception("quota")
+        error.code = 503  # type: ignore[attr-defined]
+
+        assert _get_http_status(error) == 503
+
+    def test_ignores_a_string_code(self):
+        """OpenAI's APIError carries code="rate_limit_exceeded" and no status code."""
+        from posthog.ai.langchain.callbacks import _get_http_status
+
+        error = Exception("Rate limit reached")
+        error.code = "rate_limit_exceeded"  # type: ignore[attr-defined]
+
+        assert _get_http_status(error) == 0
+
+    def test_falls_back_to_zero_without_a_status(self):
+        from posthog.ai.langchain.callbacks import _get_http_status
+
+        assert _get_http_status(Exception("boom")) == 0
+
+    def test_an_error_event_records_an_integer_status(self):
+        import httpx
+        import openai
+        from unittest.mock import MagicMock
+        from uuid import uuid4
+
+        from posthog.ai.langchain import CallbackHandler
+
+        client = MagicMock()
+        client.privacy_mode = False
+        callback = CallbackHandler(client)
+        run_id = uuid4()
+        callback._set_llm_metadata(
+            serialized={},
+            run_id=run_id,
+            messages=[{"role": "user", "content": "test"}],
+            metadata={"ls_provider": "openai", "ls_model_name": "gpt-5.6-sol"},
+        )
+        error = openai.APIError(
+            "Rate limit reached",
+            request=httpx.Request("POST", "https://api.openai.com/v1/chat/completions"),
+            body={"code": "rate_limit_exceeded", "message": "Rate limit reached"},
+        )
+
+        callback._pop_run_and_capture_generation(run_id, None, error)
+
+        properties = client.capture.call_args_list[0][1]["properties"]
+        assert properties["$ai_http_status"] == 0