Custom API Routes

By default Mastra automatically exposes registered agents and workflows via the server. For additional behavior you can define your own HTTP routes.

Routes are provided with a helper registerApiRoute from @mastra/core/server. Routes can live in the same file as the Mastra instance but separating them helps keep configuration concise.

src/mastra/index.ts


import { Mastra } from "@mastra/core/mastra";
import { registerApiRoute } from "@mastra/core/server";
 
export const mastra = new Mastra({
  // ...
  server: {
    apiRoutes: [
      registerApiRoute("/my-custom-route", {
        method: "GET",
        handler: async (c) => {
          const mastra = c.get("mastra");
          const agents = await mastra.getAgent("my-agent");
 
          return c.json({ message: "Custom route" });
        },
      }),
    ],
  },
});

Once registered, a custom route will be accessible from the root of the server. For example:


curl http://localhost:4111/my-custom-route

Each route’s handler receives the Hono Context. Within the handler you can access the Mastra instance to fetch or call agents and workflows.

To add route-specific middleware pass a middleware array when calling registerApiRoute.

src/mastra/index.ts


import { Mastra } from "@mastra/core/mastra";
import { registerApiRoute } from "@mastra/core/server";
 
export const mastra = new Mastra({
  // ...
  server: {
    apiRoutes: [
      registerApiRoute("/my-custom-route", {
        method: "GET",
        middleware: [
          async (c, next) => {
            console.log(`${c.req.method} ${c.req.url}`);
            await next();
          }
        ],
        handler: async (c) => {
          return c.json({ message: "Custom route with middleware" });
        }
      })
    ]
  }
});