make sure model provider field naming is correct

routstr/upstream/base.py

@@ -203,14 +203,26 @@ class BaseUpstreamProvider:
         already reported its own provider (e.g. OpenRouter returns
         ``"provider": "Fireworks"``), otherwise just ``"<provider_type>"``
         for direct upstreams.
+
+        Idempotent: re-stamping an already-stamped payload must not nest the
+        prefix repeatedly (e.g. never ``"anthropic:anthropic"``). This matters
+        because streaming paths can apply the field more than once per chunk.
         """
         if not isinstance(response_json, dict):
             return
+        provider_type = (self.provider_type or "").strip()
         existing = response_json.get("provider")
-        if isinstance(existing, str) and existing.strip():
-            response_json["provider"] = f"{self.provider_type}:{existing.strip()}"
-        else:
-            response_json["provider"] = self.provider_type
+        existing_str = existing.strip() if isinstance(existing, str) else ""
+        if not existing_str:
+            response_json["provider"] = provider_type
+            return
+        # Already stamped by a previous pass — leave it untouched.
+        if existing_str == provider_type or existing_str.startswith(
+            f"{provider_type}:"
+        ):
+            response_json["provider"] = existing_str
+            return
+        response_json["provider"] = f"{provider_type}:{existing_str}"
 
     def inject_cost_metadata(
         self,

routstr/upstream/openrouter.py

@@ -18,6 +18,33 @@ class OpenRouterUpstreamProvider(BaseUpstreamProvider):
     supports_anthropic_messages = True
     litellm_provider_prefix = "openrouter/"
 
+    def _apply_provider_field(self, response_json: object) -> None:
+        """Stamp the ``provider`` field for OpenRouter responses.
+
+        OpenRouter is a router, not the real serving provider, so a bare
+        ``"openrouter"`` value carries no useful information. Rules:
+
+        - Real upstream sub-provider (e.g. ``"GMICloud"``) -> ``"openrouter:GMICloud"``.
+        - Missing sub-provider, or one that merely echoes ``"openrouter"`` ->
+          ``"unknown"``.
+        - Idempotent: re-stamping never produces ``"openrouter:openrouter:..."``;
+          the ``openrouter:`` prefix appears at most once.
+        """
+        if not isinstance(response_json, dict):
+            return
+        provider_type = (self.provider_type or "").strip()
+        existing = response_json.get("provider")
+        sub = existing.strip() if isinstance(existing, str) else ""
+        # Strip any already-applied "openrouter:" prefixes (idempotency).
+        prefix = f"{provider_type}:"
+        while sub.lower().startswith(prefix.lower()):
+            sub = sub[len(prefix) :].strip()
+        # No real sub-provider, or it just echoes our own router name.
+        if not sub or sub.lower() == provider_type.lower():
+            response_json["provider"] = "unknown"
+            return
+        response_json["provider"] = f"{provider_type}:{sub}"
+
     def __init__(self, api_key: str, provider_fee: float = 1.06):
         """Initialize OpenRouter provider with API key.
 

tests/unit/test_provider_field_injection.py

@@ -32,11 +32,39 @@ def test_apply_provider_field_openrouter_passthrough() -> None:
 
 
 def test_apply_provider_field_openrouter_no_upstream_provider() -> None:
-    """If OpenRouter omits the provider field, fall back to provider_type."""
+    """If OpenRouter omits the provider field, the real serving provider is
+    unknown — a bare ``openrouter`` value carries no information."""
     p = _make_provider(OpenRouterUpstreamProvider, "openrouter")
     data: dict = {"id": "gen-abc"}
     p._apply_provider_field(data)
-    assert data["provider"] == "openrouter"
+    assert data["provider"] == "unknown"
+
+
+def test_apply_provider_field_openrouter_echoes_router_name() -> None:
+    """If OpenRouter reports its own name as the provider, treat as unknown."""
+    p = _make_provider(OpenRouterUpstreamProvider, "openrouter")
+    data: dict = {"provider": "openrouter"}
+    p._apply_provider_field(data)
+    assert data["provider"] == "unknown"
+
+
+def test_apply_provider_field_openrouter_idempotent_no_double_prefix() -> None:
+    """Re-stamping must never nest the prefix: openrouter only once."""
+    p = _make_provider(OpenRouterUpstreamProvider, "openrouter")
+    data: dict = {"provider": "GMICloud"}
+    p._apply_provider_field(data)
+    assert data["provider"] == "openrouter:GMICloud"
+    # Second pass (e.g. streaming) keeps a single prefix.
+    p._apply_provider_field(data)
+    assert data["provider"] == "openrouter:GMICloud"
+
+
+def test_apply_provider_field_openrouter_collapses_existing_double_prefix() -> None:
+    """A pre-existing double prefix is collapsed to a single one."""
+    p = _make_provider(OpenRouterUpstreamProvider, "openrouter")
+    data: dict = {"provider": "openrouter:openrouter:GMICloud"}
+    p._apply_provider_field(data)
+    assert data["provider"] == "openrouter:GMICloud"
 
 
 def test_apply_provider_field_strips_whitespace() -> None:
@@ -50,28 +78,24 @@ def test_apply_provider_field_blank_upstream_treated_as_missing() -> None:
     p = _make_provider(OpenRouterUpstreamProvider, "openrouter")
     data: dict = {"provider": "   "}
     p._apply_provider_field(data)
-    assert data["provider"] == "openrouter"
+    assert data["provider"] == "unknown"
 
 
 def test_apply_provider_field_non_string_upstream_treated_as_missing() -> None:
     p = _make_provider(OpenRouterUpstreamProvider, "openrouter")
     data: dict = {"provider": 42}
     p._apply_provider_field(data)
-    assert data["provider"] == "openrouter"
+    assert data["provider"] == "unknown"
 
 
 def test_apply_provider_field_idempotent_for_direct_upstream() -> None:
-    """Calling twice on a direct upstream payload should keep the same
-    value, not nest the prefix repeatedly."""
+    """Calling twice on a direct upstream payload keeps the same value and
+    never nests the prefix (no ``anthropic:anthropic``)."""
     p = _make_provider(AnthropicUpstreamProvider, "anthropic")
     data: dict = {}
     p._apply_provider_field(data)
     p._apply_provider_field(data)
-    assert data["provider"] == "anthropic:anthropic"
-    # Document current (deliberate) behavior: second pass treats the
-    # first-pass value as an upstream-reported provider. Callers should
-    # only invoke this once per chunk — guarded via the
-    # ``"provider" not in data`` checks in streaming paths.
+    assert data["provider"] == "anthropic"
 
 
 def test_apply_provider_field_ignores_non_dict() -> None: