fix(langfuse): honor ssl_verify=False and SSL_VERIFY on the v4 OTLP exporter

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/integrations/langfuse/langfuse_sdk.py

@@ -431,22 +431,24 @@ def _build_verified_span_exporter(*, public_key: object, secret_key: object, bas
     bundle and client certificate; v4 ships every observation through its own
     OTLP exporter, so a private-CA deployment would fail TLS on every export in
     a background thread while ``auth_check`` (still on the httpx client) stays
-    green. Only built when custom TLS material is configured; endpoint and
-    headers mirror ``langfuse._client.span_processor``.
+    green. Only built when TLS is configured away from the default (a CA bundle,
+    a client certificate, or verification switched off); endpoint and headers
+    mirror ``langfuse._client.span_processor``.
     """
     import litellm
+    from litellm.llms.custom_httpx.http_handler import get_ssl_verify
 
-    ca_bundle: Final = litellm.ssl_verify if isinstance(litellm.ssl_verify, str) else None
+    ssl_verify: Final = get_ssl_verify()
     configured_certificate: Final = os.getenv("SSL_CERTIFICATE") or litellm.ssl_certificate
     client_certificate: Final = configured_certificate if isinstance(configured_certificate, str) else None
-    if ca_bundle is None and client_certificate is None:
+    if ssl_verify is True and client_certificate is None:
         return None
     from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
 
     export_path: Final = os.getenv("LANGFUSE_OTEL_TRACES_EXPORT_PATH")
     endpoint: Final = f"{base_url}/{export_path}" if export_path else f"{base_url}/api/public/otel/v1/traces"
     encoded_auth: Final = b64encode(f"{public_key}:{secret_key}".encode()).decode("ascii")
-    return OTLPSpanExporter(
+    exporter: Final = OTLPSpanExporter(
         endpoint=endpoint,
         headers={  # mutable-ok: the exporter copies these into its session headers
             "Authorization": "Basic " + encoded_auth,
@@ -454,9 +456,12 @@ def _build_verified_span_exporter(*, public_key: object, secret_key: object, bas
             "x-langfuse-sdk-version": version("langfuse"),
             "x-langfuse-public-key": str(public_key),
         },
-        certificate_file=ca_bundle,
+        certificate_file=ssl_verify if isinstance(ssl_verify, str) else None,
         client_certificate_file=client_certificate,
     )
+    if ssl_verify is False:
+        exporter._certificate_file = False  # pyright: ignore[reportPrivateUsage]  # the ctor coerces a False certificate_file back to True
+    return exporter
 
 
 def acquire_langfuse_client(

tests/test_litellm/integrations/langfuse/test_langfuse_sdk.py

@@ -955,7 +955,8 @@ def test_ssl_exporter_is_only_built_with_custom_tls_material(monkeypatch, tmp_pa
     import litellm
     from litellm.integrations.langfuse.langfuse_sdk import _build_verified_span_exporter
 
-    monkeypatch.delenv("SSL_CERTIFICATE", raising=False)
+    for name in ("SSL_CERTIFICATE", "SSL_VERIFY", "SSL_CERT_FILE"):
+        monkeypatch.delenv(name, raising=False)
     monkeypatch.setattr(litellm, "ssl_verify", True)
     monkeypatch.setattr(litellm, "ssl_certificate", None)
     assert (
@@ -973,6 +974,38 @@ def test_ssl_exporter_is_only_built_with_custom_tls_material(monkeypatch, tmp_pa
     assert exporter._headers["x-langfuse-sdk-version"] == installed_langfuse_version()
 
 
+@pytest.mark.parametrize("switch", ["attribute", "env"])
+def test_ssl_exporter_disables_verification_when_litellm_does(monkeypatch, switch):
+    """v2 exported through the httpx client, so ``ssl_verify=False`` reached ingestion; v4's exporter must match."""
+    import litellm
+    from litellm.integrations.langfuse.langfuse_sdk import _build_verified_span_exporter
+
+    for name in ("SSL_CERTIFICATE", "SSL_VERIFY", "SSL_CERT_FILE"):
+        monkeypatch.delenv(name, raising=False)
+    monkeypatch.setattr(litellm, "ssl_certificate", None)
+    if switch == "attribute":
+        monkeypatch.setattr(litellm, "ssl_verify", False)
+    else:
+        monkeypatch.setattr(litellm, "ssl_verify", True)
+        monkeypatch.setenv("SSL_VERIFY", "False")
+
+    exporter = _build_verified_span_exporter(public_key="pk", secret_key="sk", base_url="https://lf.internal.example")
+    assert exporter is not None
+    assert exporter._certificate_file is False
+    assert exporter._client_cert is None
+
+    posted = []
+
+    def post(self, url, **kwargs):
+        posted.append((url, kwargs["verify"]))
+        raise ConnectionError("stop before the network")
+
+    monkeypatch.setattr("requests.Session.post", post)
+    with pytest.raises(ConnectionError):
+        exporter._export(b"payload")
+    assert posted[0] == ("https://lf.internal.example/api/public/otel/v1/traces", False)
+
+
 def test_second_client_on_the_same_key_does_not_build_another_provider():
     """A discarded TracerProvider is pinned forever by its atexit hook."""
     import gc