Koa deploys, but the app is unreachable

If the build passes and the URL still fails, Koa is either not listening where the platform expects or it crashed while starting.

Last updated November 9, 2026

Check the logs

npx ezhst logs --tail 200

An exception here means the app crashed at boot. A missing variable is a common reason.

Check host and port

Call app.listen(Number(process.env.PORT), "0.0.0.0").

src/index.ts

import Koa from "koa";

const app = new Koa();

app.use((ctx) => {
  ctx.body = "Hello from EasyHost";
});

app.listen(Number(process.env.PORT), "0.0.0.0");

Check the start command

Koa starts with scripts.start, then main, index.js or server.js.

npx ezhst build show

Known cause for Koa

Koa ships without a router or body parser. Add @koa/router and koa-bodyparser for the examples on this site.

See the Koa hub for every Koa guide, or free Koa hosting for what is included.

Start for free

Install the skill, choose Global or Local, then tell your agent to deploy. No credit card, no config files.

npx ezhst skill install