fix(providers): forward default_headers to Anthropic/Bedrock clients

CHANGELOG.md

@@ -7,6 +7,21 @@ the GitHub Release body, so a release with no entry here fails.
 
 Versioning follows [docs/versioning.md](docs/versioning.md).
 
+## [0.11.1] - 2026-09-24
+
+### Fixed
+
+- `build_protocol_client` now forwards `cfg["default_headers"]` to
+  `AnthropicClient` for both `protocol: anthropic` and `protocol: bedrock`.
+  Previously the headers were silently dropped, so gateway routing/auth headers
+  never reached those requests. Consumers that shimmed the builder to work
+  around this (ApodexHarness `miroharness.infra.protocol_client`) can revert to
+  a pure alias after upgrading.
+- Anthropic/Bedrock clients now also send `X-Title`, matching the Responses
+  client.
+- The `protocol: responses` builder now merges `cfg["default_headers"]` with
+  its `X-Title` header instead of discarding them.
+
 ## [0.11.0] - 2026-09-14
 
 ### Added

agent_core/providers/protocol_client.py

@@ -110,7 +110,9 @@ def _effort_str(cfg: dict[str, Any]) -> str:
     return effort.strip() if isinstance(effort, str) else ""
 
 
-def _build_anthropic(cfg: dict[str, Any], *, bedrock: bool = False) -> LLMClient:
+def _build_anthropic(
+    cfg: dict[str, Any], title: str, *, bedrock: bool = False
+) -> LLMClient:
     """Native Anthropic Messages API with extended thinking.
 
     Responses carry thinking + signature blocks, kept verbatim
@@ -119,7 +121,8 @@ def _build_anthropic(cfg: dict[str, Any], *, bedrock: bool = False) -> LLMClient
     ``{base_url}/v1/messages`` (direct) or ``{base_url}/model/{id}/invoke``
     (``bedrock=True``, AWS Bedrock runtime, Bearer API-key auth + the
     ``anthropic_version`` body stamp). Optional ``effort`` →
-    ``output_config.effort``.
+    ``output_config.effort``. ``default_headers`` (gateway routing / auth
+    headers) is merged over ``X-Title``, as in the Responses builder.
 
     ``thinking_type`` selects the request shape (default ``adaptive``). Live-
     verified against api.anthropic.com + Bedrock 2026-07-09 (see
@@ -169,6 +172,7 @@ def _build_anthropic(cfg: dict[str, Any], *, bedrock: bool = False) -> LLMClient
         max_tokens=max_tokens,
         thinking=thinking,
         effort=effort,
+        default_headers={"X-Title": title, **(cfg.get("default_headers") or {})},
         bedrock=bedrock,
     )
 
@@ -227,7 +231,7 @@ def _build_responses(cfg: dict[str, Any], title: str) -> LLMClient:
         base_url=cfg.get("base_url"),
         temperature=cfg.get("temperature"),
         max_output_tokens=cfg.get("max_tokens", 32768),
-        default_headers={"X-Title": title},
+        default_headers={"X-Title": title, **(cfg.get("default_headers") or {})},
         reasoning=reasoning or None,
         store=False,
     )
@@ -245,9 +249,9 @@ def build_protocol_client(cfg: dict[str, Any], *, title: str) -> LLMClient | Non
     """
     protocol = protocol_of(cfg)
     if protocol == "anthropic":
-        return _build_anthropic(cfg)
+        return _build_anthropic(cfg, title)
     if protocol == "bedrock":
-        return _build_anthropic(cfg, bedrock=True)
+        return _build_anthropic(cfg, title, bedrock=True)
     if protocol == "responses":
         return _build_responses(cfg, title)
     return None

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "apodex-agent-core"
-version = "0.11.0"
+version = "0.11.1"
 description = "Shared, product-neutral runtime primitives for Apodex agents"
 readme = "README.md"
 license = "Apache-2.0"

tests/test_provider_protocol_reasoning.py

@@ -527,3 +527,46 @@ def test_absent_or_valid_protocol_is_not_logged(cfg, caplog):
     with caplog.at_level(logging.WARNING):
         protocol_of(cfg)
     assert "unknown llm.protocol" not in caplog.text
+
+
+@pytest.mark.parametrize("protocol", ["anthropic", "bedrock"])
+def test_anthropic_builders_forward_default_headers(monkeypatch, protocol):
+    # Regression: the builder used to drop cfg["default_headers"], so gateway
+    # routing/auth headers never reached Anthropic or Bedrock requests.
+    import agent_core.providers.anthropic as anthropic_mod
+
+    seen = {}
+
+    def fake_init(self, *args, **kwargs):
+        seen.update(kwargs)
+
+    monkeypatch.setattr(anthropic_mod.AnthropicClient, "__init__", fake_init)
+    headers = {"X-Route": "gw-a"}
+    build_protocol_client(
+        {"model": "claude-x", "protocol": protocol, "api_key": "k",
+         "default_headers": headers}, title="T")
+    assert seen["default_headers"] == {"X-Title": "T", "X-Route": "gw-a"}
+    assert headers == {"X-Route": "gw-a"}
+    assert seen["bedrock"] is (protocol == "bedrock")
+
+    build_protocol_client({"model": "claude-x", "protocol": protocol}, title="T")
+    assert seen["default_headers"] == {"X-Title": "T"}
+
+
+def test_openai_responses_builder_merges_default_headers(monkeypatch):
+    # Gateway headers from cfg must reach the Responses client alongside X-Title.
+    import agent_core.providers.openai_responses as responses_mod
+
+    seen = {}
+
+    def fake_init(self, *args, **kwargs):
+        seen.update(kwargs)
+
+    monkeypatch.setattr(responses_mod.OpenAIResponsesClient, "__init__", fake_init)
+    build_protocol_client(
+        {"model": "gpt-x", "protocol": "responses", "api_key": "k",
+         "default_headers": {"X-Route": "gw-a"}}, title="T")
+    assert seen["default_headers"] == {"X-Title": "T", "X-Route": "gw-a"}
+
+    build_protocol_client({"model": "gpt-x", "protocol": "responses"}, title="T")
+    assert seen["default_headers"] == {"X-Title": "T"}