`app.silent`

Suppresses Koa's built-in error logging to `stderr` when set to `true`.

Syntax

app.silent = true | false

Parameters

Name	Type	Required	Description
`value`	`boolean`	Yes	When `true`, Koa will not log errors to `stderr`. Useful when you supply your own `app.on('error', ...)` handler. Defaults to `false`.

Returns

void — Setter; returns nothing.

Examples

import Koa from 'koa';

const app = new Koa();
app.silent = true;

app.on('error', (err, ctx) => {
  // Custom structured logging
  console.error(JSON.stringify({ msg: err.message, path: ctx.path }));
});

app.use(async (ctx) => {
  ctx.throw(400, 'Bad input');
});

app.listen(3000);

Output

{"msg":"Bad input","path":"/"}

Notes

By default Koa logs 5xx errors via `console.error`; 4xx errors are never logged (they are expected client errors). Set `app.silent = true` when you attach a structured logger via `app.on('error', ...)` to avoid duplicate output.