Koa

Mount the Files gateway on a Koa app. Sets ctx.respond = false and bridges ctx.req/ctx.res to the Web Request/Response the gateway speaks.

files-sdk/koa mounts a createFilesRouter on a Koa app. Koa wraps the Node IncomingMessage/ServerResponse as ctx.req/ctx.res, so the binding bridges them to the Web Request/Response the gateway speaks (the same Readable.toWeb/fromWeb seam as the Express adapter). Setting ctx.respond = false steps Koa back so the gateway writes the raw response itself, and a client disconnect is wired through to abort the upstream read on a proxied download.

import Koa from "koa";
import { createFiles } from "files-sdk";
import { s3 } from "files-sdk/s3";
import { createFilesRouter } from "files-sdk/api";
import { createRouteHandler } from "files-sdk/koa";

const router = createFilesRouter({
  files: createFiles({ adapter: s3({ bucket: "uploads" }) }),
  allowedOrigins: ["https://app.example.com"],
  authorize: async ({ req }) => {
    /* throw to deny, or return a per-user constraint — see /ui/server/authorization */
  },
});

const app = new Koa();
const files = createRouteHandler(router);

// Gate the route before any body parser (see below). Pair with @koa/router if
// you prefer: router.all("/api/files", (ctx) => files(ctx)).
app.use((ctx, next) => (ctx.path === "/api/files" ? files(ctx) : next()));

app.listen(3000);

See the gateway options for the full configuration and the authorize model for locking it down.