feat(agentgateway): add Agent Gateway module for MCP tool discovery and invocation

[prashantrakheja]

Description

Add the Agent Gateway module (sap_cloud_sdk.agentgateway) — a framework-agnostic client for discovering and invoking MCP tools via SAP Agent Gateway.

Key capabilities:

• Automatic flow detection: Detects LoB (BTP Destination Service) vs Customer (mTLS file-based credentials) based on environment
• Tool discovery: Lists MCP tools from all configured servers
• Tool invocation: Calls MCP tools with user principal propagation (jwt-bearer token exchange)
• LLM-safe tool naming: Sanitizes and namespaces tool names to conform to LLM API constraints (64 chars, ^[a-zA-Z0-9-_]+$)
• LangChain integration: Converter to transform MCP tools into LangChain StructuredTool objects

Type of Change

• New feature (non-breaking change that adds functionality)

How to Test

from sap_cloud_sdk.agentgateway import create_client

# Customer agent flow (reads servers from credentials integrationDependencies)
agw_client = create_client()
tools = await agw_client.list_mcp_tools()
result = await agw_client.call_mcp_tool(tool=tools[0], user_token="jwt")

# LoB agent flow (uses BTP Destination Service)
agw_client = create_client(tenant_subdomain="my-tenant")
tools = await agw_client.list_mcp_tools()
result = await agw_client.call_mcp_tool(tool=tools[0], user_token="jwt")

Unit tests:

uv run pytest tests/agentgateway/unit/ -v

Checklist

• My code follows the project's Code Guidelines
• I have added type hints for all public APIs
• I have added unit tests covering the new functionality
• I have added or updated the user guide (user-guide.md) in the module directory
• All existing tests pass locally
• My commits follow Conventional Commits format
• No confidential or SAP-internal information is included

[cla-assistant]

All committers have signed the CLA.

[NicoleMGomes]

Missing user-guide.md