mcp-playground

MCP Playground 🛠️🌩️

A Streamlit-based playground that lets you chat with large language models and seamlessly plug in external Multi-Server Command Protocol (MCP) tools. Spin up multiple FastMCP servers (Weather & Currency) alongside a Streamlit client, all orchestrated with Docker Compose. The client is provider-agnostic (OpenAI • Amazon Bedrock • Anthropic • Google Gemini) thanks to LangChain + LangGraph.

📖 Learn More

Want a deep dive into how it all works? Check out the detailed walkthrough in this Medium article:
https://medium.com/@elkhan.alizada/your-own-ai-agent-playground-build-it-with-streamlit-langgraph-and-docker-4caeb6fe0ac4

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🖥️🔌 Main Interface – Connected View

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🏗️ Architecture

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✨ Key Features

Feature	Description
🔌 Multi-Server MCP	Register any number of MCP servers; the agent auto-detects available tools & routes calls.
🖥️ Streamlit Chat UI	Rich chat experience with history, sidebar controls and live tool execution output.
🧩 Provider-Agnostic	One LangChain interface for OpenAI, Bedrock, Anthropic, Google, Groq. Switch on the fly.
🤖 React Agent via LangGraph	create_react_agent enables dynamic tool selection and reasoning.
🐳 Docker-First	Separate Dockerfiles for client & each server + a single docker-compose.yaml.
📦 Extensible	Drop-in new MCP servers or providers without touching UI code.

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📂 Project Layout

mcp-playground/
├─ docker-compose.yaml          # One-command orchestration
├─ client/                      # Streamlit UI
│  ├─ app.py                    # Main entry-point
│  ├─ config.py                 # Typed settings & defaults
│  ├─ servers_config.json       # MCP endpoint catalogue
│  ├─ ui_components/            # Streamlit widgets
│  └─ ...
└─ servers/
   ├─ server1/                  # Weather Service MCP
   │  └─ main.py
   └─ server2/                  # Currency Exchange MCP
      └─ main.py

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🚀 Quick Start

1 · Prerequisites

• Docker ≥ 24 & Docker Compose
• At least one LLM provider key (e.g. OPENAI_API_KEY) or AWS creds for Bedrock.

2 · Clone & Run

git clone https://github.com/your-org/mcp-playground.git
cd mcp-playground
docker compose up --build

Service	URL	Default Port
Streamlit Client	http://localhost:8501	8501
Weather MCP	http://localhost:8000	8000
Currency MCP	http://localhost:8001	8001

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⚙️ Configuration

All runtime settings are concentrated in client/config.py and environment variables.

Variable	Purpose
MODEL_ID	Provider selector (OpenAI, Bedrock, Anthropic, Google, Groq).
TEMPERATURE	Sampling temperature (sidebar slider).
MAX_TOKENS	Token limit (sidebar).

MODEL_OPTIONS = {
    'OpenAI': 'gpt-4o',
    'Antropic': 'claude-3-5-sonnet-20240620',
    'Google': 'gemini-2.0-flash-001',
    'Bedrock': 'us.anthropic.claude-3-7-sonnet-20250219-v1:0',
    'Groq': 'meta-llama/llama-4-scout-17b-16e-instruct'
}

MCP endpoints live in servers_config.json – edit to add/remove servers without code changes.

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💬 Using the Playground

1. Select Provider · Pick your LLM in the sidebar and paste the corresponding credentials.
2. Connect MCP Servers · Toggle connections; available tools appear in the MCP Tools list.
3. Chat · Type a question.
   • If connected, the React agent decides whether to call an MCP tool (e.g. get_current_weather).
   • Otherwise it falls back to plain LLM chat.
4. Inspect Tool Calls · Tool invocations are streamed back as YAML blocks with inputs & outputs.

Try: "What will the weather be in Baku tomorrow and how much is 100 USD in AZN?"

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🛠️ Included MCP Servers

Weather Service :8000

mcp = FastMCP("Weather Service", host="0.0.0.0", port=8000)

@mcp.tool()
async def get_current_weather(location: str) -> dict: ...

@mcp.tool()
async def get_forecast(location: str, days: int = 3) -> dict: ...

Currency Exchange :8001

mcp = FastMCP("Currency Exchange", host="0.0.0.0", port=8001)

@mcp.tool()
async def get_currency_rates(date: str = None) -> dict: ...

@mcp.tool()
async def convert_currency(amount: float, from_currency: str, to_currency: str, date: str = None) -> dict: ...

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🙏 Acknowledgements

• LangChain
• LangGraph
• FastMCP
• Streamlit

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