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Static file serving middleware.


$ npm install koa-send


  • maxage Browser cache max-age in milliseconds. defaults to 0
  • hidden Allow transfer of hidden files. defaults to false
  • root Root directory to restrict file access
  • gzip Try to serve the gzipped version of a file automatically when gzip is supported by a client and if the requested file with .gz extension exists. defaults to true.
  • format If not false (defaults to true), format the path to serve static file servers and not require a trailing slash for directories, so that you can do both /directory and /directory/
  • setHeaders Function to set custom headers on response.

Root path

Note that root is required, defaults to '' and will be resolved, removing the leading / to make the path relative and this path must not contain "..", protecting developers from concatenating user input. If you plan on serving files based on user input supply a root directory from which to serve from.

For example to serve files from ./public:

app.use(function *(){
  yield send(this, this.path, { root: __dirname + '/public' });

To serve developer specified files:

app.use(function *(){
  yield send(this, 'path/to/my.js');


The function is called as fn(res, path, stats), where the arguments are:

  • res: the response object
  • path: the resolved file path that is being sent
  • stats: the stats object of the file that is being sent.

You should only use the setHeaders option when you wish to edit the Cache-Control or Last-Modified headers, because doing it before is useless (it's overwritten by send), and doing it after is too late because the headers are already sent.

If you want to edit any other header, simply set them before calling send.

Example (Koa@2) with async/await

var send = require('koa-send');
var Koa = require('koa');
var app = new Koa();
// $ GET /package.json 
// $ GET / 
app.use(async function (ctx, next){
  if ('/' == ctx.path) return ctx.body = 'Try GET /package.json';
  await send(ctx, ctx.path);
console.log('listening on port 3000');


var send = require('koa-send');
var koa = require('koa');
var app = koa();
// $ GET /package.json 
// $ GET / 
app.use(function *(){
  if ('/' == this.path) return this.body = 'Try GET /package.json';
  yield send(this, this.path);
console.log('listening on port 3000');