feat(perplexity): add integration attribution header

litellm/llms/perplexity/chat/transformation.py

@@ -27,6 +27,21 @@ class PerplexityChatConfig(OpenAIGPTConfig):
         dynamic_api_key = api_key or get_secret_str("PERPLEXITYAI_API_KEY") or get_secret_str("PERPLEXITY_API_KEY")
         return api_base, dynamic_api_key
 
+    def validate_environment(
+        self,
+        headers: dict,
+        model: str,
+        messages: list[AllMessageValues],
+        optional_params: dict,
+        litellm_params: dict,
+        api_key: str | None = None,
+        api_base: str | None = None,
+    ) -> dict:
+        headers.setdefault("X-Pplx-Integration", "litellm")
+        return super().validate_environment(
+            headers, model, messages, optional_params, litellm_params, api_key, api_base
+        )
+
     def get_supported_openai_params(self, model: str) -> list:
         """
         Perplexity supports a subset of OpenAI params

tests/test_litellm/llms/perplexity/chat/test_perplexity_chat_transformation.py

@@ -19,6 +19,21 @@ from litellm.types.utils import Usage
 class TestPerplexityChatTransformation:
     """Test suite for Perplexity chat transformation functionality."""
 
+    @pytest.mark.parametrize(
+        ("headers", "expected"),
+        [({}, "litellm"), ({"X-Pplx-Integration": "custom"}, "custom")],
+    )
+    def test_integration_header_default_is_caller_overridable(self, headers, expected):
+        result = PerplexityChatConfig().validate_environment(
+            headers=headers,
+            model="sonar",
+            messages=[],
+            optional_params={},
+            litellm_params={},
+        )
+
+        assert result["X-Pplx-Integration"] == expected
+
     def test_enhance_usage_with_citation_tokens(self):
         """Test extraction of citation tokens from API response."""
         config = PerplexityChatConfig()