fix: match mcp headers in provider data to Responses API shape (#2263)

llama_stack/providers/remote/tool_runtime/model_context_protocol/config.py

@@ -10,8 +10,8 @@ from pydantic import BaseModel
 
 
 class MCPProviderDataValidator(BaseModel):
-    # mcp_endpoint => list of headers to send
-    mcp_headers: dict[str, list[str]] | None = None
+    # mcp_endpoint => dict of headers to send
+    mcp_headers: dict[str, dict[str, str]] | None = None
 
 
 class MCPProviderConfig(BaseModel):

llama_stack/providers/remote/tool_runtime/model_context_protocol/model_context_protocol.py

@@ -18,7 +18,7 @@ from llama_stack.apis.tools import (
 from llama_stack.distribution.request_headers import NeedsRequestProviderData
 from llama_stack.log import get_logger
 from llama_stack.providers.datatypes import ToolGroupsProtocolPrivate
-from llama_stack.providers.utils.tools.mcp import convert_header_list_to_dict, invoke_mcp_tool, list_mcp_tools
+from llama_stack.providers.utils.tools.mcp import invoke_mcp_tool, list_mcp_tools
 
 from .config import MCPProviderConfig
 
@@ -69,5 +69,5 @@ class ModelContextProtocolToolRuntimeImpl(ToolGroupsProtocolPrivate, ToolRuntime
             for uri, values in provider_data.mcp_headers.items():
                 if canonicalize_uri(uri) != canonicalize_uri(mcp_endpoint_uri):
                     continue
-                headers.update(convert_header_list_to_dict(values))
+                headers.update(values)
         return headers

llama_stack/providers/utils/tools/mcp.py

@@ -51,16 +51,6 @@ async def sse_client_wrapper(endpoint: str, headers: dict[str, str]):
         raise
 
 
-def convert_header_list_to_dict(header_list: list[str]) -> dict[str, str]:
-    headers = {}
-    for header in header_list:
-        parts = header.split(":")
-        if len(parts) == 2:
-            k, v = parts
-            headers[k.strip()] = v.strip()
-    return headers
-
-
 async def list_mcp_tools(endpoint: str, headers: dict[str, str]) -> ListToolDefsResponse:
     tools = []
     async with sse_client_wrapper(endpoint, headers) as session:

tests/integration/tool_runtime/test_mcp.py

@@ -40,9 +40,9 @@ def test_mcp_invocation(llama_stack_client, mcp_server):
 
     provider_data = {
         "mcp_headers": {
-            uri: [
-                f"Authorization: Bearer {AUTH_TOKEN}",
-            ],
+            uri: {
+                "Authorization": f"Bearer {AUTH_TOKEN}",
+            },
         },
     }
     auth_headers = {