Applicability
When to Use
✓When building APIs that aggregate multiple backends
✓When you need unified authentication and rate limiting
✓When external consumers should not know about internal MCP servers
Overview
How It Works
The API Gateway pattern provides a single entry point for external consumers while routing requests to the appropriate MCP servers behind the scenes. The gateway handles authentication, rate limiting, request transformation, and response aggregation.
In an MCP architecture, the gateway agent receives HTTP requests, maps them to MCP server tool calls, and returns formatted responses. This abstracts the MCP server implementation details from API consumers.
Implementation
Code Example
typescript
const routes = {
"GET /users/:id": async (params) => {
const user = await postgres.query("SELECT * FROM users WHERE id=$1", [params.id]);
const orders = await stripe.listCharges({ customer: user.stripeId, limit: 5 });
return { ...user, recentOrders: orders.data };
},
"POST /tickets": async (params, body) => {
const ticket = await zendesk.createTicket({ subject: body.subject, description: body.description });
await slack.sendMessage({ channel: "#support", text: `New ticket: ${ticket.id}` });
return ticket;
}
};
async function gateway(method, path, body) {
const route = matchRoute(`${method} ${path}`, routes);
if (!route) return { status: 404 };
try {
const result = await route.handler(route.params, body);
return { status: 200, body: result };
} catch (error) {
return { status: error.status || 500, body: { error: error.message } };
}
}Quick Info
Categoryintegration
ComplexityMedium