feat(agentgateway): enhance credential detection logic for service bi…

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "sap-cloud-sdk"
-version = "0.31.0"
+version = "0.32.0"
 description = "SAP Cloud SDK for Python"
 readme = "README.md"
 license = "Apache-2.0"

src/sap_cloud_sdk/agentgateway/__init__.py

@@ -63,6 +63,7 @@
 from sap_cloud_sdk.agentgateway.agw_client import create_client, AgentGatewayClient
 from sap_cloud_sdk.agentgateway.exceptions import (
     AgentGatewaySDKError,
+    AgentGatewayServerError,
     MCPServerNotFoundError,
 )
 
@@ -82,5 +83,6 @@
     "AgentCardFilter",
     # Exceptions
     "AgentGatewaySDKError",
+    "AgentGatewayServerError",
     "MCPServerNotFoundError",
 ]

src/sap_cloud_sdk/agentgateway/_customer.py

@@ -26,14 +26,20 @@
 )
 from sap_cloud_sdk.agentgateway._token_cache import _TokenCache
 from sap_cloud_sdk.agentgateway.exceptions import AgentGatewaySDKError
+from sap_cloud_sdk.core.secret_resolver import resolve_base_mount
 
 logger = logging.getLogger(__name__)
 
-# Environment variable to override default credential path
+# Environment variable to override default credential path (points directly to credentials file)
 _CREDENTIALS_PATH_ENV = "AGW_CREDENTIALS_PATH"
 
-# Default credential path for Kyma production deployments
-_CREDENTIALS_DEFAULT_PATH = "/etc/ums/credentials/credentials"
+# servicebinding.io: scan $SERVICE_BINDING_ROOT for a binding whose 'type' file equals the expected type
+_BINDING_TYPE = "integration-credentials"
+_BINDING_TYPE_FILE = "type"
+_CREDENTIALS_FILE = "credentials"
+
+# Kyma default when SERVICE_BINDING_ROOT is not set
+_DEFAULT_BINDING_ROOT = "/bindings"
 
 # Resource URN for Agent Gateway token scope (hardcoded - production value)
 _AGW_RESOURCE_URN = "urn:sap:identity:application:provider:name:agent-gateway"
@@ -66,24 +72,38 @@ def detect_customer_agent_credentials() -> str | None:
     """Check if customer agent credentials file exists.
 
     Checks for credential file in the following order:
-    1. Path specified in AGW_CREDENTIALS_PATH env var
-    2. Default mounted path: /etc/ums/credentials/credentials
+    1. Path specified in AGW_CREDENTIALS_PATH env var (explicit override, points to file directly)
+    2. $SERVICE_BINDING_ROOT (or /bindings if unset): scans all subdirectories for one whose
+       'type' file contains 'integration-credentials', then reads 'credentials' from that directory
 
     Returns:
         Path to credentials file if found, None otherwise.
     """
-    # Check env var first (path may be customized)
+    # 1. Explicit override via env var
     path_from_env = os.environ.get(_CREDENTIALS_PATH_ENV)
     if path_from_env and os.path.isfile(path_from_env):
         logger.debug("Customer credentials found at env var path: %s", path_from_env)
         return path_from_env
 
-    # Check default mounted path
-    if os.path.isfile(_CREDENTIALS_DEFAULT_PATH):
-        logger.debug(
-            "Customer credentials found at default path: %s", _CREDENTIALS_DEFAULT_PATH
-        )
-        return _CREDENTIALS_DEFAULT_PATH
+    # 2. servicebinding.io: scan $SERVICE_BINDING_ROOT for a binding whose 'type' file equals _BINDING_TYPE
+    sbr = resolve_base_mount(_DEFAULT_BINDING_ROOT)
+    if sbr and os.path.isdir(sbr):
+        for entry in os.scandir(sbr):
+            if not entry.is_dir():
+                continue
+            type_file = os.path.join(entry.path, _BINDING_TYPE_FILE)
+            if not os.path.isfile(type_file):
+                continue
+            with open(type_file) as f:
+                if f.read().strip() != _BINDING_TYPE:
+                    continue
+            credentials_path = os.path.join(entry.path, _CREDENTIALS_FILE)
+            if os.path.isfile(credentials_path):
+                logger.debug(
+                    "Customer credentials found via servicebinding.io type scan: %s",
+                    credentials_path,
+                )
+                return credentials_path
 
     return None
 
@@ -128,16 +148,17 @@ def load_customer_credentials(path: str) -> CustomerCredentials:
     if _CredentialFields.INTEGRATION_DEPENDENCIES not in data:
         raise AgentGatewaySDKError(
             "Credentials file missing required field: integrationDependencies. "
-            'Expected format: [{"ordId": "...", "data": {"globalTenantId": "..."}}]'
+            'Expected format: [{"ordId": "...", "globalTenantId": "..."}]'
         )
 
     try:
         integration_deps = [
             IntegrationDependency(
                 ord_id=dep[_CredentialFields.ORD_ID],
-                global_tenant_id=dep[_CredentialFields.DATA][
-                    _CredentialFields.GLOBAL_TENANT_ID
-                ],
+                global_tenant_id=(
+                    dep.get(_CredentialFields.GLOBAL_TENANT_ID)
+                    or dep[_CredentialFields.DATA][_CredentialFields.GLOBAL_TENANT_ID]
+                ),
             )
             for dep in data[_CredentialFields.INTEGRATION_DEPENDENCIES]
         ]
@@ -148,7 +169,7 @@ def load_customer_credentials(path: str) -> CustomerCredentials:
     except (KeyError, TypeError) as e:
         raise AgentGatewaySDKError(
             f"Failed to parse integrationDependencies: {e}. "
-            'Expected format: [{"ordId": "...", "data": {"globalTenantId": "..."}}]'
+            'Expected format: [{"ordId": "...", "globalTenantId": "..."}]'
         )
 
     return CustomerCredentials(
@@ -216,7 +237,6 @@ def _request_token_mtls(
     credentials: CustomerCredentials,
     grant_type: str,
     timeout: float,
-    app_tid: str | None = None,
     extra_data: dict | None = None,
 ) -> dict:
     """Make mTLS token request to IAS.
@@ -225,7 +245,6 @@ def _request_token_mtls(
         credentials: Customer credentials with certificate and private key.
         grant_type: OAuth2 grant type.
         timeout: HTTP timeout in seconds.
-        app_tid: BTP Application Tenant ID of subscriber (optional).
         extra_data: Additional form data for the token request.
 
     Returns:
@@ -242,11 +261,6 @@ def _request_token_mtls(
         "resource": _AGW_RESOURCE_URN,
     }
 
-    # TODO: app_tid requirement is still being clarified with the IBD team.
-    # This parameter may be removed if it turns out to be unnecessary.
-    if app_tid:
-        data["app_tid"] = app_tid
-
     if extra_data:
         data.update(extra_data)
 
@@ -326,7 +340,6 @@ def get_system_token_mtls(
         credentials,
         grant_type=_GRANT_TYPE_CLIENT_CREDENTIALS,
         timeout=timeout,
-        app_tid=app_tid,
         extra_data={"response_type": "token"},
     )
     access_token = token_data["access_token"]
@@ -372,15 +385,17 @@ def exchange_user_token(
             return cached_token
 
     logger.info("Exchanging user token for AGW-scoped token via jwt-bearer grant")
+    extra: dict = {
+        "assertion": user_token,
+        "token_format": "jwt",
+    }
+    if app_tid:
+        extra["app_tid"] = app_tid
     token_data = _request_token_mtls(
         credentials,
         grant_type=_GRANT_TYPE_JWT_BEARER,
         timeout=timeout,
-        app_tid=app_tid,
-        extra_data={
-            "assertion": user_token,
-            "token_format": "jwt",
-        },
+        extra_data=extra,
     )
     access_token = token_data["access_token"]
 
@@ -476,26 +491,64 @@ async def _list_server_tools(
                 ]
 
 
+def _resolve_dependency(
+    credentials: CustomerCredentials,
+    ord_id: str,
+) -> IntegrationDependency:
+    """Resolve a single IntegrationDependency by ORD ID.
+
+    Args:
+        credentials: Customer credentials with integrationDependencies.
+        ord_id: ORD ID to look up.
+
+    Returns:
+        The matching IntegrationDependency.
+
+    Raises:
+        AgentGatewaySDKError: If no match is found or multiple entries share the same ORD ID.
+    """
+    matches = [d for d in credentials.integration_dependencies if d.ord_id == ord_id]
+    if not matches:
+        available = ", ".join(d.ord_id for d in credentials.integration_dependencies)
+        raise AgentGatewaySDKError(
+            f"ORD ID '{ord_id}' not found in integrationDependencies. "
+            f"Available: {available or '(none)'}"
+        )
+    if len(matches) > 1:
+        tids = ", ".join(m.global_tenant_id for m in matches)
+        raise AgentGatewaySDKError(
+            f"ORD ID '{ord_id}' matches multiple integrationDependencies with "
+            f"different tenant IDs ({tids}). Specify the tenant ID explicitly."
+        )
+    return matches[0]
+
+
 async def get_mcp_tools_customer(
     credentials: CustomerCredentials,
     system_token: str,
     timeout: float,
+    ord_id: str | None = None,
 ) -> list[MCPTool]:
-    """List all MCP tools from servers defined in credentials.
+    """List MCP tools from servers defined in credentials.
 
-    Iterates over all integrationDependencies in the credentials file and
-    discovers tools from each MCP server using a pre-fetched system token.
+    When ord_id is given, only tools from that single dependency are returned
+    and the tenant ID is derived automatically from the credentials.
+    When ord_id is omitted, tools from all integrationDependencies are returned.
 
     Args:
         credentials: Customer credentials with integrationDependencies.
         system_token: Pre-fetched raw system token for authentication.
         timeout: HTTP timeout in seconds for MCP server calls.
+        ord_id: Optional ORD ID to filter to a single server. The tenant ID
+            is derived from the credentials — no need to pass it separately.
+            Raises AgentGatewaySDKError if the ORD ID matches multiple entries.
 
     Returns:
-        List of MCPTool objects from all servers.
+        List of MCPTool objects from the matching server(s).
 
     Raises:
-        AgentGatewaySDKError: If integrationDependencies is empty.
+        AgentGatewaySDKError: If integrationDependencies is empty, or if ord_id
+            is given but not found or matches multiple tenant IDs.
     """
     dependencies = credentials.integration_dependencies
 
@@ -504,6 +557,9 @@ async def get_mcp_tools_customer(
             "integrationDependencies is empty in credentials — no MCP servers configured."
         )
 
+    if ord_id is not None:
+        dependencies = [_resolve_dependency(credentials, ord_id)]
+
     logger.info("Discovering tools from %d MCP server(s)", len(dependencies))
 
     tools: list[MCPTool] = []

src/sap_cloud_sdk/agentgateway/_mcp_session.py

@@ -0,0 +1,93 @@
+"""Shared helpers for MCP session management."""
+
+import logging
+import uuid
+
+import httpx
+from mcp import ClientSession, McpError
+from mcp.client.streamable_http import streamable_http_client
+
+from sap_cloud_sdk.agentgateway._models import MCPTool
+from sap_cloud_sdk.agentgateway.exceptions import AgentGatewayServerError
+
+logger = logging.getLogger(__name__)
+
+
+async def invoke_mcp_tool(
+    tool: MCPTool, auth_token: str, timeout: float, **kwargs
+) -> str:
+    """Open an MCP session, call a tool, and return its text result.
+
+    Handles McpError from both initialize() and call_tool(), and checks
+    result.isError, raising AgentGatewayServerError in all three cases.
+
+    Args:
+        tool: MCPTool to invoke.
+        auth_token: Raw bearer token for the Authorization header.
+        timeout: HTTP timeout in seconds.
+        **kwargs: Tool input parameters forwarded to call_tool().
+
+    Returns:
+        Tool result as a string, or "" if the response has no content.
+
+    Raises:
+        AgentGatewayServerError: If the server returns any kind of error.
+    """
+    async with httpx.AsyncClient(
+        headers={
+            "Authorization": f"Bearer {auth_token}",
+            "x-correlation-id": str(uuid.uuid4()),
+        },
+        timeout=timeout,
+    ) as http_client:
+        try:
+            async with streamable_http_client(tool.url, http_client=http_client) as (
+                read,
+                write,
+                _,
+            ):
+                async with ClientSession(read, write) as session:
+                    try:
+                        await session.initialize()
+                    except McpError as e:
+                        raise AgentGatewayServerError(
+                            f"Agent Gateway rejected MCP session for tool '{tool.name}': {e.error.message}",
+                            error_code=e.error.code,
+                        ) from e
+                    try:
+                        result = await session.call_tool(tool.name, kwargs)
+                    except McpError as e:
+                        raise AgentGatewayServerError(
+                            f"Agent Gateway returned error for tool '{tool.name}': {e.error.message}",
+                            error_code=e.error.code,
+                        ) from e
+                    if result is None:
+                        logger.warning("Tool '%s' returned a null result", tool.name)
+                        return ""
+                    if result.isError:
+                        raise AgentGatewayServerError(
+                            f"Tool '{tool.name}' returned an error: {_error_text(result.content)}"
+                        )
+                    if not result.content:
+                        return ""
+                    return str(getattr(result.content[0], "text", ""))
+        except BaseExceptionGroup as eg:
+            # anyio wraps task-group exceptions into ExceptionGroups. If the only
+            # leaf exception is AttributeError it means an older MCP library version
+            # crashed on a null result body inside call_tool. Re-raise anything else.
+            attr_errors, rest = eg.split(AttributeError)
+            if rest is not None:
+                raise
+            logger.warning(
+                "Tool '%s' returned a null result (MCP null-result bug: %s)",
+                tool.name,
+                attr_errors,
+            )
+            return ""
+
+
+def _error_text(content: list) -> str:
+    """Extract a human-readable message from MCP error content blocks."""
+    texts = [getattr(block, "text", None) for block in content]
+    message = " ".join(t for t in texts if t)
+    return message or "unknown error"