# 🧩 Unit 2 (Part 2): Building MCP Clients

Now that we've built and deployed an MCP server using Gradio, it’s time to build **MCP clients** that can interact with it — both in the browser (JavaScript) and backend (Python). We’ll also show how to build a UI-driven MCP client using Gradio itself.

---

## 📁 Configuring MCP Clients

### MCP Configuration Files

MCP clients typically read from a `mcp.json` file to know how to connect to servers. Here's a basic example:

```json
{
  "servers": [
    {
      "name": "MCP Server",
      "transport": {
        "type": "sse",
        "url": "http://localhost:7860/gradio_api/mcp/sse"
      }
    }
  ]
}
```

- **`type: sse`** – Use this for remote servers (like Hugging Face Spaces)
- **`type: stdio`** – Use this for local scripts or CLI tools

### Example for Remote (Hugging Face Space):

```json
{
  "servers": [
    {
      "name": "Sentiment Tool",
      "transport": {
        "type": "sse",
        "url": "https://japhari-mcp-sentiment.hf.space/gradio_api/mcp/sse"
      }
    }
  ]
}
```

---

## 🧠 Python Client using `smolagents`

### Install dependencies:

```bash
pip install "smolagents[mcp]" "gradio[mcp]"
```

### Simple Python Client:

```python
from smolagents import ToolCollection, CodeAgent, InferenceClientModel
from mcp.client.sse import SSEServerParameters

server = SSEServerParameters(url="http://localhost:7860/gradio_api/mcp/sse")

with ToolCollection.from_mcp(server, trust_remote_code=True) as tools:
    agent = CodeAgent(tools=[*tools.tools], model=InferenceClientModel())
    agent.run("What is the sentiment of 'I love MCP?'")
```

This client connects to your server, loads available tools, and allows LLM-driven execution.

---

## 🌐 JavaScript Client using HuggingFace.js (Example)

If you're using a UI front end (e.g., React or Vue), you can call your MCP server using any SSE-capable HTTP client.

```json
{
  "mcpServers": {
    "mcp": {
      "url": "http://localhost:7860/gradio_api/mcp/sse"
    }
  }
}
```

This config can be used with tools like `mcp-remote` or integrated into a custom JS agent.

---

## 🖥 Gradio as an MCP Client (UI Agent)

### Concept

Gradio isn’t just for building servers — it can also be used to build **UI wrappers around MCP Clients**. This is powerful when you want a browser interface for tools provided by another MCP server.

---

### Step-by-Step Example

Install necessary libraries:

```bash
pip install "smolagents[mcp]" "gradio[mcp]" mcp
```

Create a new file: `app.py`

```python
import gradio as gr
from smolagents import InferenceClientModel, CodeAgent
from smolagents.mcp_client import MCPClient

try:
    # Connect to a remote MCP server
    mcp_client = MCPClient({
        "url": "http://localhost:7860/gradio_api/mcp/sse"
        # or test this working remote one:
        # "url": "https://abidlabs-mcp-tools.hf.space/gradio_api/mcp/sse"
    })
    tools = mcp_client.get_tools()
    model = InferenceClientModel()
    agent = CodeAgent(tools=[*tools], model=model)

    # Gradio UI
    demo = gr.ChatInterface(
        fn=lambda msg, history: str(agent.run(msg)),
        type="messages",
        title="Agent with MCP Tools",
        examples=["What is the sentiment of 'That’s awesome!'"],
        description="A UI MCP Client that connects to a remote tool server"
    )

    demo.launch()
finally:
    mcp_client.disconnect()
```

---

### Deploy to Hugging Face Spaces

1. Go to [https://huggingface.co/spaces](https://huggingface.co/spaces)
2. Click **“Create new Space”**
3. Choose **Gradio** SDK
4. Name it something like: `mcp-client-ui`
5. Create `requirements.txt`:

```
gradio[mcp]
smolagents[mcp]
```

6. Push it:

```bash
git init
git add app.py requirements.txt
git commit -m "MCP client UI"
git remote add origin https://huggingface.co/spaces/YOUR_USERNAME/mcp-client-ui
git push -u origin main
```