fix(openrouter): forward attribution headers into LiteLLM requests

src/rotator_library/client.py

@@ -65,6 +65,43 @@ def __init__(self, message, data=None):
         self.data = data
 
 
+OPENROUTER_ATTRIBUTION_HEADER_KEYS = (
+    "HTTP-Referer",
+    "X-OpenRouter-Title",
+    "X-Title",
+    "X-OpenRouter-Categories",
+)
+
+
+def _get_request_header(request: Optional[Any], key: str) -> Optional[str]:
+    if request is None:
+        return None
+    headers = getattr(request, "headers", None)
+    if headers is None:
+        return None
+    if hasattr(headers, "get"):
+        value = headers.get(key)
+        if value is None:
+            value = headers.get(key.lower())
+        return value
+    if isinstance(headers, dict):
+        return headers.get(key) or headers.get(key.lower())
+    return None
+
+
+def _merge_openrouter_extra_headers(
+    litellm_kwargs: Dict[str, Any], request: Optional[Any]
+) -> Dict[str, Any]:
+    extra_headers = dict(litellm_kwargs.get("extra_headers") or {})
+    for key in OPENROUTER_ATTRIBUTION_HEADER_KEYS:
+        value = _get_request_header(request, key)
+        if value and key not in extra_headers:
+            extra_headers[key] = value
+    if extra_headers:
+        litellm_kwargs["extra_headers"] = extra_headers
+    return litellm_kwargs
+
+
 class RotatingClient:
     """
     A client that intelligently rotates and retries API keys using LiteLLM,
@@ -1698,6 +1735,8 @@ async def _execute_with_retry(
                         ]
 
                     litellm_kwargs = sanitize_request_payload(litellm_kwargs, model)
+                    if provider == "openrouter":
+                        litellm_kwargs = _merge_openrouter_extra_headers(litellm_kwargs, request)
 
                     for attempt in range(self.max_retries):
                         try:
@@ -2431,6 +2470,8 @@ async def _streaming_acompletion_with_retry(
                         ]
 
                     litellm_kwargs = sanitize_request_payload(litellm_kwargs, model)
+                    if provider == "openrouter":
+                        litellm_kwargs = _merge_openrouter_extra_headers(litellm_kwargs, request)
 
                     # If the provider is 'qwen_code', set the custom provider to 'qwen'
                     # and strip the prefix from the model name for LiteLLM.

tests/test_client_routing_policy.py

@@ -1,3 +1,4 @@
+import importlib
 import sys
 import asyncio
 import random
@@ -9,8 +10,13 @@
 ROOT = Path(__file__).resolve().parents[1]
 sys.path.insert(0, str(ROOT / "src"))
 
-from rotator_library.client import RotatingClient
-from rotator_library.routing_policy import RoutingPolicy, RoutingPolicyError
+client_module = importlib.import_module("rotator_library.client")
+routing_policy_module = importlib.import_module("rotator_library.routing_policy")
+
+RotatingClient = getattr(client_module, "RotatingClient")
+_merge_openrouter_extra_headers = getattr(client_module, "_merge_openrouter_extra_headers")
+RoutingPolicy = getattr(routing_policy_module, "RoutingPolicy")
+RoutingPolicyError = getattr(routing_policy_module, "RoutingPolicyError")
 
 
 def test_client_helper_rewrites_weighted_router_model():
@@ -125,3 +131,42 @@ def test_client_helper_rewrites_weighted_qwen3_5_model():
     assert decision is not None
     assert decision.strategy == "weighted"
     assert decision.excluded_providers == ["opencode_go"]
+
+
+def test_merge_openrouter_extra_headers_copies_attribution_from_request():
+    class Request:
+        headers = {
+            "HTTP-Referer": "https://opencode.ai",
+            "X-OpenRouter-Title": "OpenCode/opencode-router",
+            "X-Title": "OpenCode/opencode-router",
+            "X-OpenRouter-Categories": "cli-agent",
+        }
+
+    kwargs = _merge_openrouter_extra_headers({"messages": []}, Request())
+
+    assert kwargs["extra_headers"]["HTTP-Referer"] == "https://opencode.ai"
+    assert kwargs["extra_headers"]["X-OpenRouter-Title"] == "OpenCode/opencode-router"
+    assert kwargs["extra_headers"]["X-Title"] == "OpenCode/opencode-router"
+    assert kwargs["extra_headers"]["X-OpenRouter-Categories"] == "cli-agent"
+
+
+def test_merge_openrouter_extra_headers_preserves_existing_values():
+    class Request:
+        headers = {
+            "HTTP-Referer": "https://opencode.ai",
+            "X-OpenRouter-Title": "OpenCode/opencode-router",
+        }
+
+    kwargs = _merge_openrouter_extra_headers(
+        {
+            "extra_headers": {
+                "HTTP-Referer": "https://custom.example",
+                "Existing": "value",
+            }
+        },
+        Request(),
+    )
+
+    assert kwargs["extra_headers"]["HTTP-Referer"] == "https://custom.example"
+    assert kwargs["extra_headers"]["X-OpenRouter-Title"] == "OpenCode/opencode-router"
+    assert kwargs["extra_headers"]["Existing"] == "value"