chore(otel/v2): drop bundled langtrace v1 endpoint fix

The langtrace v1 exporter host/header fix (https://app.langtrace.ai/api/trace +
x-api-key) and the shared endpoint-normalizer /api/trace carve-out are unrelated
to admin-owned OTEL v2 destinations; they change behavior on the legacy langtrace
v1 path. Moved to its own PR (#34865) so this PR only touches OTEL v2. The v2
langtrace preset and its normalizer in otel/plumbing/providers.py are unaffected.

litellm/integrations/opentelemetry.py

@@ -3093,10 +3093,6 @@ class OpenTelemetry(OTELGenAISemconvMixin, CustomLogger):
         if signal_type == "traces" and "/v2/trace/otlp" in endpoint:
             return endpoint
 
-        # Langtrace ingests traces at /api/trace (a complete path, not an OTLP base). Do not rewrite.
-        if signal_type == "traces" and endpoint.endswith("/api/trace"):
-            return endpoint
-
         # Check if endpoint already ends with the correct signal path
         target_path = f"/v1/{signal_type}"
         if endpoint.endswith(target_path):

litellm/litellm_core_utils/litellm_logging.py

@@ -3992,9 +3992,9 @@ def _init_custom_logger_compatible_class(
 
             otel_config = OpenTelemetryConfig(
                 exporter="otlp_http",
-                endpoint="https://app.langtrace.ai/api/trace",
+                endpoint="https://langtrace.ai/api/trace",
             )
-            os.environ["OTEL_EXPORTER_OTLP_TRACES_HEADERS"] = f"x-api-key={os.getenv('LANGTRACE_API_KEY')}"
+            os.environ["OTEL_EXPORTER_OTLP_TRACES_HEADERS"] = f"api_key={os.getenv('LANGTRACE_API_KEY')}"
             for callback in _in_memory_loggers:
                 if isinstance(callback, OpenTelemetry) and callback.callback_name == "langtrace":
                     return callback  # type: ignore

tests/test_litellm/integrations/test_opentelemetry.py

@@ -1928,21 +1928,12 @@ class TestOpenTelemetryEndpointNormalization(unittest.TestCase):
                 "https://example.com/prefix/v2/trace/otlp",
                 "https://example.com/prefix/v2/trace/otlp",
             ),
-            (
-                "https://app.langtrace.ai/api/trace",
-                "https://app.langtrace.ai/api/trace",
-            ),
-            (
-                "https://app.langtrace.ai/api/trace/",
-                "https://app.langtrace.ai/api/trace",
-            ),
         ]
     )
     def test_normalize_traces_nonstandard_otlp_ingest_urls_unchanged(
         self, input_url: str, expected: str
     ) -> None:
-        """Vendor full-path ingest URLs (Splunk /v2/trace/otlp, Langtrace /api/trace)
-        must not get /v1/traces appended — that 404s."""
+        """Splunk-style /v2/trace/otlp endpoints must not get /v1/traces appended."""
         otel = OpenTelemetry()
         self.assertEqual(
             otel._normalize_otel_endpoint(input_url, "traces"),
@@ -5861,45 +5852,3 @@ class TestOpenTelemetryMetricAttributeFiltering(unittest.TestCase):
                         exporter="console", attributes=attributes
                     )
                 )
-
-
-class LangtraceV1ConfigTest(unittest.TestCase):
-    def test_langtrace_uses_live_host_and_x_api_key_header(self):
-        """Regression: litellm hardcoded the stale https://langtrace.ai/api/trace (now 404)
-        with header ``api_key=``. The live ingest is https://app.langtrace.ai/api/trace and
-        the auth header is ``x-api-key``. Pins both so the stale values can't return."""
-        import litellm
-        import litellm.litellm_core_utils.litellm_logging as ll
-        from litellm.integrations.opentelemetry import OpenTelemetry
-        from litellm.integrations.otel.model.config import is_otel_v2_enabled
-
-        saved = {
-            k: os.environ.get(k)
-            for k in (
-                "LANGTRACE_API_KEY",
-                "LITELLM_OTEL_V2",
-                "OTEL_EXPORTER_OTLP_TRACES_HEADERS",
-            )
-        }
-        try:
-            ll._in_memory_loggers.clear()  # force a fresh build, not a cached logger
-            os.environ["LANGTRACE_API_KEY"] = "lt-test"
-            os.environ.pop("LITELLM_OTEL_V2", None)
-            is_otel_v2_enabled.cache_clear()
-            litellm.credential_list = []
-            logger = ll._init_custom_logger_compatible_class("langtrace", None, None)
-            assert isinstance(logger, OpenTelemetry)
-            self.assertEqual(
-                logger.config.endpoint, "https://app.langtrace.ai/api/trace"
-            )
-            self.assertEqual(
-                os.environ["OTEL_EXPORTER_OTLP_TRACES_HEADERS"], "x-api-key=lt-test"
-            )
-        finally:
-            is_otel_v2_enabled.cache_clear()
-            ll._in_memory_loggers.clear()
-            for key, value in saved.items():
-                if value is None:
-                    os.environ.pop(key, None)
-                else:
-                    os.environ[key] = value