fix(mcp_proxy_for_aws/utils.py): add override for bedrock-agentcore service name detection

README.md

@@ -79,7 +79,7 @@ docker build -t mcp-proxy-for-aws .
 |----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------|---	|
 | `endpoint`	          | MCP endpoint URL (e.g., `https://your-service.us-east-1.amazonaws.com/mcp`)	                                                                                                                                                            | N/A	                                                                        |Yes	|
 | ---	                 | ---	                                                                                                                                                                                                                                    | ---	                                                                        |---	|
-| `--service`	         | AWS service name for SigV4 signing	                                                                                                                                                                                                     | Inferred from endpoint if not provided	                                     |No	|
+| `--service`	         | AWS service name for SigV4 signing, if omitted we try to infer this from the url	                                                                                                                                                       | Inferred from endpoint if not provided	                                     |No	|
 | `--profile`	         | AWS profile for AWS credentials to use	                                                                                                                                                                                                 | Uses `AWS_PROFILE` environment variable if not set                          |No	|
 | `--region`	          | AWS region to use	                                                                                                                                                                                                                      | Uses `AWS_REGION` environment variable if not set, defaults to `us-east-1`	 |No	|
 | `--metadata`	        | Metadata to inject into MCP requests as key=value pairs (e.g., `--metadata KEY1=value1 KEY2=value2`)                                                                                                                                    | `AWS_REGION` is automatically injected based on `--region` if not provided    |No	|
@@ -279,6 +279,15 @@ uv sync
 
 ---
 
+## Troubleshooting
+
+### Handling `Authentication error - Invalid credentials`
+We try to autodetect the service from the url, sometimes this fails, ensure that `--service` is set correctly to the
+service you are attempting to connect to.
+Otherwise the SigV4 signing will not be able to be verified by the service you connect to, resulting in this error.
+Also ensure that you have valid IAM credentials on your machine before retrying.
+
+
 ## Development & Contributing
 
 For development setup, testing, and contribution guidelines, see:

mcp_proxy_for_aws/utils.py

@@ -18,10 +18,9 @@
 import httpx
 import logging
 import os
-import re
 from fastmcp.client.transports import StreamableHttpTransport
 from mcp_proxy_for_aws.sigv4_helper import create_sigv4_client
-from typing import Any, Dict, Optional
+from typing import Any, Dict, Optional, Tuple
 from urllib.parse import urlparse
 
 
@@ -72,34 +71,61 @@ def client_factory(
     )
 
 
+def get_service_name_and_region_from_endpoint(endpoint: str) -> Tuple[str, str]:
+    """Extract service name and region from an endpoint URL.
+
+    Args:
+        endpoint: The endpoint URL to parse
+
+    Returns:
+        Tuple of (service_name, region). Either value may be empty string if not found.
+
+    Notes:
+        - Matches bedrock-agentcore endpoints (gateway and runtime)
+        - Matches AWS API Gateway endpoints (service.region.api.aws)
+        - Falls back to extracting first hostname segment as service name
+    """
+    # Parse AWS service from endpoint URL
+    parsed = urlparse(endpoint)
+    hostname = parsed.hostname or ''
+    match hostname.split('.'):
+        case [*_, 'bedrock-agentcore', region, 'amazonaws', 'com']:
+            return 'bedrock-agentcore', region  # gateway and runtime
+        case [service, region, 'api', 'aws']:
+            return service, region
+        case [service, *_]:
+            # Fallback: extract first segment as service name
+            return service, ''
+        case _:
+            logger.warning('Could not parse endpoint, no hostname found')
+            return '', ''
+
+
 def determine_service_name(endpoint: str, service: Optional[str] = None) -> str:
-    """Validate and determine the service name.
+    """Validate and determine the service name and possibly region from an endpoint.
 
     Args:
         endpoint: The endpoint URL
         service: Optional service name
 
     Returns:
         Validated service name
+        Validated region
 
     Raises:
         ValueError: If service cannot be determined
     """
     if service:
         return service
 
-    # Parse AWS service from endpoint URL
-    parsed = urlparse(endpoint)
-    hostname = parsed.hostname or ''
-
-    # Extract service name (first part before first dot or dash)
-    service_match = re.match(r'^([^.]+)', hostname)
-    determined_service = service_match.group(1) if service_match else None
+    logger.info('Resolving service name')
+    endpoint_service, _ = get_service_name_and_region_from_endpoint(endpoint)
+    determined_service = service or endpoint_service
 
     if not determined_service:
         raise ValueError(
-            f"Could not determine AWS service name from endpoint '{endpoint}'. "
-            'Please provide the service name explicitly using --service argument.'
+            f"Could not determine AWS service name and region from endpoint '{endpoint}' and they were not provided."
+            'Please provide the service name explicitly using --service argument and the region via --region argument.'
         )
     return determined_service
 
@@ -122,14 +148,10 @@ def determine_aws_region(endpoint: str, region: Optional[str]) -> str:
         return region
 
     # Parse AWS region from endpoint URL
-    parsed = urlparse(endpoint)
-    hostname = parsed.hostname or ''
-
-    # Extract region name (pattern: service.region.api.aws or service-name.region.api.aws)
-    region_match = re.search(r'\.([a-z0-9-]+)\.api\.aws', hostname)
-    if region_match:
+    _, endpoint_region = get_service_name_and_region_from_endpoint(endpoint)
+    if endpoint_region:
         logger.debug('Region determined through endpoint URL')
-        return region_match.group(1)
+        return endpoint_region
 
     environment_region = os.getenv('AWS_REGION')
     if environment_region:

tests/unit/test_utils.py

@@ -136,6 +136,20 @@ def test_validate_service_name_service_parsing_with_dot(self):
         result = determine_service_name(endpoint)
         assert result == 'service'
 
+    def test_validate_service_name_bedrock_agentcore(self):
+        """Test parsing service name for bedrock-agentcore endpoints."""
+        # Test various bedrock-agentcore endpoint formats
+        test_cases = [
+            'https://my-agent.gateway.bedrock-agentcore.us-west-2.amazonaws.com',  # Clean gateway
+            'https://bedrock-agentcore.us-east-1.amazonaws.com',  # Clean runtime
+            'https://bedrock-agentcore.us-east-1.amazonaws.com/runtimes/arn%3Aaws%3Abedrock-agentcore%3Aus-east-1%3A216123456714%3Aruntime%2Fhosted_agent_99wdf-hYKYrgAHVr/invocations',
+            'https://gateway-quick-start-242206-rsdehprct2.gateway.bedrock-agentcore.eu-central-1.amazonaws.com/mcp',
+        ]
+
+        for endpoint in test_cases:
+            result = determine_service_name(endpoint)
+            assert result == 'bedrock-agentcore', f'Failed for endpoint: {endpoint}'
+
     def test_validate_service_name_service_parsing_simple_hostname(self):
         """Test parsing service from simple hostname."""
         endpoint = 'https://myservice'