MCP Playground

A Python toolkit for interacting with remote Model Context Protocol (MCP) endpoints. Supports Streamable HTTP (default) and SSE transports, with LLM-powered tool selection across multiple providers.

Quick Start

git clone https://github.com/zanetworker/mcp-playground.git
cd mcp-playground
pip install -e ".[all]"

Usage

Context Manager (recommended)

import asyncio
from mcp_playground import MCPClient

async def main():
    async with MCPClient("http://localhost:8000/mcp") as client:
        tools = await client.list_tools()
        print(f"Found {len(tools)} tools")

        result = await client.call_tool("add", arguments={"a": 10, "b": 5})
        print(f"Result: {result.content}")

asyncio.run(main())

SSE Transport (legacy servers)

async with MCPClient("http://localhost:8000/sse", transport="sse") as client:
    tools = await client.list_tools()

Custom Auth / Headers

import httpx

http = httpx.AsyncClient(headers={"Authorization": "Bearer token"})
async with MCPClient("http://localhost:8000/mcp", http_client=http) as client:
    tools = await client.list_tools()

One-Shot Usage

For simple scripts that don't need a persistent connection:

client = MCPClient("http://localhost:8000/mcp")
tools = await client.list_tools()  # auto-connects and disconnects

LLM-Powered Tool Selection

Let an LLM choose and execute the right MCP tool based on natural language:

import os
from mcp_playground import MCPClient
from mcp_playground.llm_bridge import OpenAIBridge

async with MCPClient("http://localhost:8000/mcp") as client:
    bridge = OpenAIBridge(client, api_key=os.environ["OPENAI_API_KEY"])
    result = await bridge.process_query("Add 10 and 5")

    if result["tool_call"]:
        print(f"Tool: {result['tool_call']['name']}")
        print(f"Result: {result['tool_result'].content}")

Supported LLM Providers

Provider	Bridge Class	Default Model
OpenAI	OpenAIBridge	gpt-4o
Anthropic	AnthropicBridge	claude-sonnet-4-20250514
Ollama	OllamaBridge	llama3.3
OpenRouter	OpenRouterBridge	any model ID

Interactive Playground (Streamlit)

cd mcp-streamlit-app
pip install -r requirements.txt
streamlit run app.py

Features:

• Transport selector (Streamable HTTP / SSE)
• Multi-provider LLM support (OpenAI, Anthropic, Ollama, OpenRouter)
• Chat modes: Auto, Chat-only, Tools-only
• Tool discovery and invocation
• Real-time connection status

API Reference

MCPClient

client = MCPClient(
    endpoint="http://localhost:8000/mcp",
    transport="streamable-http",  # or "sse"
    timeout=30.0,
    http_client=None,  # optional httpx.AsyncClient
)

Methods:

Method	Description
list_tools()	List available tools from the MCP endpoint
call_tool(name, arguments={})	Invoke a tool with parameters
invoke_tool(name, kwargs)	Backward-compatible alias for call_tool()
check_connection()	Check if the endpoint is reachable
get_endpoint_info()	Get endpoint metadata
connect() / disconnect()	Manual session lifecycle

ToolInvocationResult

result = await client.call_tool("add", arguments={"a": 1, "b": 2})
result.content             # Text content as string
result.error_code          # 0 for success, 1 for error
result.structured_content  # Structured output (dict), if available
result.raw_content         # Raw content blocks from the SDK

Error Handling

from mcp_playground import MCPClient, MCPConnectionError, MCPTimeoutError

try:
    async with MCPClient("http://localhost:8000/mcp") as client:
        tools = await client.list_tools()
except MCPConnectionError as e:
    print(f"Connection failed: {e}")
except MCPTimeoutError as e:
    print(f"Timed out: {e}")

Requirements

• Python >= 3.10
• mcp >= 1.26.0
• httpx >= 0.28.0
• pydantic >= 2.0.0

Optional (for LLM integration):

• openai >= 2.28.0
• anthropic >= 0.84.0
• ollama >= 0.6.0

Development

pip install -e ".[dev]"
pytest                # run tests
black .               # format code
ruff check .          # lint

License

MIT