# Connecting MCP Inspector to SingleStore MCP Server
This document provides detailed instructions for connecting the MCP Inspector to the SingleStore MCP Server.
## Starting the Server
1. Start the server with:
```bash
npm run start:inspector
```
2. Look for the following lines in the server output:
```
MCP SingleStore SSE server listening on port 8081
MCP Inspector compatible endpoints:
- http://localhost:8081/stream
- http://localhost:8081/mcp-sse
```
## Connecting MCP Inspector
There are several ways to start the MCP Inspector:
### Option 1: Using the Combined Script
Run:
```bash
npm run inspector
```
This script will start both the server and the MCP Inspector.
### Option 2: Starting the Inspector Separately
If the server is already running:
```bash
npx @modelcontextprotocol/inspector
```
### Connection Options
When the MCP Inspector opens, try one of the following URLs in order of recommendation:
1. Standard MCP Inspector connection endpoint:
```
http://localhost:8081/connect?transportType=sse
```
2. Primary SSE Stream endpoint:
```
http://localhost:8081/stream
```
3. Alternative SSE endpoint:
```
http://localhost:8081/mcp-sse
```
4. Root server URL:
```
http://localhost:8081
```
Make sure "SSE" is selected as the transport type in the dropdown.
## Troubleshooting
If you encounter connection issues:
1. **Debug Headers**:
```bash
npm run debug:headers
```
This will check the Content-Type headers returned by different endpoints.
2. **Test SSE Connection**:
```bash
npm run test:sse
```
This will test if the SSE connection is working properly.
3. **Check Server Logs**:
Look for messages like:
- `[SSE] Connection attempt from 127.0.0.1 with transport sse`
- `[SSE] Set Content-Type header: text/event-stream`
4. **Common Issues**:
- If you see `Invalid content type, expected "text/event-stream"`, try using the `/stream` or `/mcp-sse` endpoints
- If you see connection timeouts, ensure the server is running and the port is correct
- Try restarting both the server and the MCP Inspector
5. **Manual Testing**:
You can try a direct curl request:
```bash
curl -N http://localhost:8081/stream
```
You should see events streaming in.
## Endpoint Reference
| Endpoint | Purpose |
|----------|---------|
| `/` | Root endpoint - server information |
| `/connect?transportType=sse` | Standard MCP Inspector connection endpoint (recommended) |
| `/stream` | Primary SSE endpoint for MCP Inspector |
| `/mcp-sse` | Alternative SSE endpoint with different header setting |
| `/sse` | Standard SSE endpoint |
| `/health` | Health check endpoint |
| `/tools` | List available tools |
| `/call-tool` | Execute a tool (POST) |
## Common Connection URLs
Below are the complete connection URLs to try in the MCP Inspector, in order of most likely to work:
1. `http://localhost:8081/connect?transportType=sse`
2. `http://localhost:8081/stream`
3. `http://localhost:8081/mcp-sse`
4. `http://localhost:8081`