mcp-test

pytest integration and CLI for testing MCP servers.

[](https://pypi.org/project/mcp-pytest/)

pip install mcp-pytest

> After installing, the CLI command is mcp-test. The Python import is from mcp_test import MCPClient.

No other MCP testing tools exist. If you're building a Python MCP server, you need this.

List tools your server exposes:

mcp-test list "python my_server.py"

Call a tool:

mcp-test call "python my_server.py" search '{"query": "hello"}'

Smoke test (verify server starts and tools respond):

mcp-test check "python my_server.py" --smoke

Write real tests for your MCP server:

# conftest.py
# (no extra setup needed — the mcp_server fixture is auto-registered)

# test_my_server.py
def test_tools_exist(mcp_server):
    tools = mcp_server.list_tools()
    assert len(tools) > 0, "Server should expose at least one tool"

def test_search_returns_results(mcp_server):
    result = mcp_server.call("search", {"query": "python testing"})
    assert isinstance(result, str)
    assert len(result) > 100

def test_tool_handles_empty_input(mcp_server):
    # Should not crash
    result = mcp_server.call_raw("search", {"query": ""})
    assert result.get("isError") is False or "error" in str(result)

Run with:

pytest --mcp-server "python my_server.py"

Or set in pytest.ini:

[pytest]
mcp_server_command = python my_server.py

Use directly in code (no pytest needed):

from mcp_test import MCPClient

with MCPClient(["python", "my_server.py"]) as server:
    # List all tools
    tools = server.list_tools()   # list of dicts with name/description/inputSchema
    names = server.tool_names()   # just the names

    # Call a tool
    result = server.call("search", {"query": "hello"})   # returns text or list
    raw = server.call_raw("search", {"quer