UAT: MCPToolAdapter never reaches a real MCP server #6969

New issue

Open

opened 2026-04-10 06:06:42 +00:00 by HAL9000 · 0 comments

HAL9000 commented

2026-04-10 06:06:42 +00:00

Owner

What was tested

Reviewed the MCP integration (docs/specification.md, MCP section) against the implementation in src/cleveragents/mcp on commit 51aab18411.

Expected behavior

MCPToolAdapter.connect() should select the appropriate transport (stdio/SSE/HTTP) and complete the MCP initialize handshake so tool discovery works.
McpClient.start() (or lazy call_tool) should succeed in connecting, discovering tools, and invoking them when an MCP server is available.

Actual behavior

MCPTransport (the default transport in src/cleveragents/mcp/adapter.py, lines 154-172) is an abstract stub whose connect() and call() methods raise NotImplementedError.
MCPToolAdapter.__init__ (lines 186-197) always instantiates MCPTransport() when no override is provided, so connect() immediately triggers NotImplementedError.
McpClient.start()/call_tool() invoke self._adapter.connect() and discover_tools(), so they also crash with the same NotImplementedError before any handshake or discovery can occur.

Steps to reproduce

In a Python shell with the current codebase, run:

from cleveragents.mcp.client import McpClient, McpClientConfig
from cleveragents.mcp.adapter import MCPServerConfig

cfg = McpClientConfig(server=MCPServerConfig(name='demo', transport='stdio', command='demo-server'))
client = McpClient(cfg)
client.start()

The call to client.start() raises NotImplementedError: MCPTransport.connect() because no concrete transport is provided.

Code location

src/cleveragents/mcp/adapter.py
src/cleveragents/mcp/client.py

## What was tested - Reviewed the MCP integration (`docs/specification.md`, MCP section) against the implementation in `src/cleveragents/mcp` on commit 51aab184112728471a44d5a91c334663cf8cd016. ## Expected behavior - `MCPToolAdapter.connect()` should select the appropriate transport (stdio/SSE/HTTP) and complete the MCP initialize handshake so tool discovery works. - `McpClient.start()` (or lazy `call_tool`) should succeed in connecting, discovering tools, and invoking them when an MCP server is available. ## Actual behavior - `MCPTransport` (the default transport in `src/cleveragents/mcp/adapter.py`, lines 154-172) is an abstract stub whose `connect()` and `call()` methods raise `NotImplementedError`. - `MCPToolAdapter.__init__` (lines 186-197) always instantiates `MCPTransport()` when no override is provided, so `connect()` immediately triggers `NotImplementedError`. - `McpClient.start()`/`call_tool()` invoke `self._adapter.connect()` and `discover_tools()`, so they also crash with the same `NotImplementedError` before any handshake or discovery can occur. ## Steps to reproduce 1. In a Python shell with the current codebase, run: ```python from cleveragents.mcp.client import McpClient, McpClientConfig from cleveragents.mcp.adapter import MCPServerConfig cfg = McpClientConfig(server=MCPServerConfig(name='demo', transport='stdio', command='demo-server')) client = McpClient(cfg) client.start() ``` 2. The call to `client.start()` raises `NotImplementedError: MCPTransport.connect()` because no concrete transport is provided. ## Code location - `src/cleveragents/mcp/adapter.py` - `src/cleveragents/mcp/client.py`

Rows
Columns