# MCP Gateway in 5 Minutes
Get from zero to a working gateway with tools your AI can use.
## Prerequisites
- **Rust toolchain** (1.85+): [rustup.rs](https://rustup.rs)
## 1. Install
```bash
cargo install mcp-gateway
```
Or via Homebrew (macOS/Linux):
```bash
brew tap MikkoParkkola/tap
brew install mcp-gateway
```
## 2. Create a Config
Save this as `gateway.yaml`:
```yaml
server:
port: 39400
meta_mcp:
enabled: true
capabilities:
enabled: true
directories:
- ./capabilities
backends: {}
```
## 3. Add Capabilities
Create a `capabilities/` directory and add two free capabilities (no API keys needed):
**capabilities/weather.yaml**
```yaml
fulcrum: "1.0"
name: weather
description: Get current weather for a location (free, no API key)
schema:
input:
type: object
properties:
latitude:
type: number
description: Latitude coordinate
longitude:
type: number
description: Longitude coordinate
required: [latitude, longitude]
providers:
primary:
service: rest
cost_per_call: 0
config:
base_url: https://api.open-meteo.com
path: /v1/forecast
method: GET
params:
latitude: "{latitude}"
longitude: "{longitude}"
current_weather: "true"
response_path: current_weather
cache:
strategy: exact
ttl: 300
auth:
required: false
metadata:
category: weather
tags: [weather, forecast, free]
```
**capabilities/wikipedia.yaml**
```yaml
fulcrum: "1.0"
name: wikipedia_summary
description: Get a Wikipedia article summary (free, no API key)
schema:
input:
type: object
properties:
title:
type: string
description: Article title (use underscores for spaces, e.g. "Albert_Einstein")
required: [title]
providers:
primary:
service: rest
cost_per_call: 0
config:
base_url: https://en.wikipedia.org
path: /api/rest_v1/page/summary/{title}
method: GET
headers:
Accept: "application/json"
cache:
strategy: exact
ttl: 86400
auth:
required: false
metadata:
category: knowledge
tags: [wikipedia, encyclopedia, free]
```
## 4. Start the Gateway
```bash
mcp-gateway --config gateway.yaml
```
You should see:
```
INFO mcp_gateway: Starting MCP Gateway on 127.0.0.1:39400
INFO mcp_gateway: Meta-MCP enabled (4 meta-tools)
INFO mcp_gateway: Loaded 2 capabilities
```
## 5. Test It
Search for tools:
```bash
curl -s http://localhost:39400/mcp \
-H "Content-Type: application/json" \
-d '{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "gateway_search_tools",
"arguments": { "query": "weather" }
}
}' | python3 -m json.tool
```
Invoke the weather tool:
```bash
curl -s http://localhost:39400/mcp \
-H "Content-Type: application/json" \
-d '{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "gateway_invoke",
"arguments": {
"server": "fulcrum",
"tool": "weather",
"arguments": { "latitude": 60.17, "longitude": 24.94 }
}
}
}' | python3 -m json.tool
```
## 6. Connect to Claude Desktop
Add this to your Claude Desktop config (`~/Library/Application Support/Claude/claude_desktop_config.json` on macOS):
```json
{
"mcpServers": {
"gateway": {
"type": "http",
"url": "http://localhost:39400/mcp"
}
}
}
```
Restart Claude Desktop. You now have access to all gateway tools via the 4 meta-tools.
See [examples/claude-desktop.json](../examples/claude-desktop.json) for a full example config.
## Next Steps
- **Add more capabilities**: Copy any YAML from the `capabilities/` directory that ships with the gateway. 25+ work with zero config.
- **Add MCP server backends**: Point `backends:` at existing MCP servers (stdio, HTTP, or SSE).
- **Enable caching**: Add `cache: { enabled: true, default_ttl: 60s }` to your config.
- **Enable auth**: Add `auth: { enabled: true, bearer_token: "auto" }` for token-based access control.
- **Install from registry**: Run `mcp-gateway cap search finance` and `mcp-gateway cap install stock_quote`.
- **Full config reference**: See the [README](../README.md#configuration-reference) or [examples/gateway-full.yaml](../examples/gateway-full.yaml).
