`ctx.request.get()`

Returns the value of a specific request header field (case-insensitive).

Syntax

ctx.request.get(field)  // or ctx.get(field)

Parameters

Name	Type	Required	Description
`field`	`string`	Yes	The header field name. Case-insensitive. `"Referrer"` and `"Referer"` are treated as aliases.

Returns

string — The header value, or an empty string `""` if not present.

Examples

import Koa from 'koa';

const app = new Koa();

app.use(async (ctx) => {
  const auth = ctx.get('Authorization');
  const ua = ctx.get('User-Agent');

  if (!auth) ctx.throw(401, 'Authorization header required');

  ctx.body = { ua };
});

app.listen(3000);

Output

curl -H 'Authorization: Bearer token123' localhost:3000
{"ua":"curl/8.7.1"}

Notes

Returns `""` (empty string) rather than `undefined` when the header is absent, making it safe to call `.startsWith()` etc. without null checks. The `Referrer`/`Referer` normalisation follows the HTTP spec.