Add integration header to Perplexity requests

src/api_perplexity_search.py

@@ -27,6 +27,7 @@
 import random
 import re
 from typing import Any, Dict, Iterable, List, Optional
+from urllib.parse import urlparse
 
 import httpx
 
@@ -216,11 +217,15 @@ def _backoff_delay(attempt: int) -> float:
 
 
 def _perplexity_headers() -> Dict[str, str]:
-    return {
+    headers = {
         "Authorization": f"Bearer {PERPLEXITY_API_KEY}",
         "Content-Type": "application/json",
         "Accept": "application/json",
     }
+    # Identify this integration to Perplexity; skipped for custom endpoints.
+    if urlparse(PERPLEXITY_ENDPOINT).hostname == "api.perplexity.ai":
+        headers["X-Pplx-Integration"] = "telegrambot-openai-api"
+    return headers
 
 
 def _extract_perplexity_content(response_data: Dict[str, Any]) -> str:

tests/test_perplexity_headers.py

@@ -0,0 +1,27 @@
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "src"))
+
+import api_perplexity_search  # noqa: E402
+
+
+def test_default_endpoint_sends_integration_header(monkeypatch):
+    monkeypatch.setattr(
+        api_perplexity_search,
+        "PERPLEXITY_ENDPOINT",
+        "https://api.perplexity.ai/chat/completions",
+    )
+    headers = api_perplexity_search._perplexity_headers()
+    assert headers["X-Pplx-Integration"] == "telegrambot-openai-api"
+    assert [k.lower() for k in headers].count("x-pplx-integration") == 1
+
+
+def test_custom_endpoint_omits_integration_header(monkeypatch):
+    for endpoint in (
+        "https://proxy.example.com/chat/completions",
+        "https://api.perplexity.ai.example.com/chat/completions",
+    ):
+        monkeypatch.setattr(api_perplexity_search, "PERPLEXITY_ENDPOINT", endpoint)
+        headers = api_perplexity_search._perplexity_headers()
+        assert "X-Pplx-Integration" not in headers