Skip to content
Switch branches/tags

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time


NPM version NPM download codebeat badge Build Status Coverage Status Gitter

Koa-Authz is an authorization middleware for Koa, it's based on Node-Casbin:


use casbin v2.x

npm install casbin@2 koa-authz@2 --save

use casbin v3.x

npm install casbin@3 koa-authz@3 --save

Simple Example

const casbin = require('casbin')
const Koa = require('koa')
const app = new Koa()
const authz = require('koa-authz')

// response
app.use(async (ctx, next) => {
  const start = new Date()
  await next()
  console.log(new Date() - start)

// use authz middleware
  newEnforcer: async() => {
    // load the casbin model and policy from files, database is also supported.
    const enforcer = await casbin.newEnforcer('authz_model.conf', 'authz_policy.csv')
    return enforcer

// reload routes
const router = require('koa-router')({prefix: '/user'})
router.get('/', (ctx) => {
  ctx.body = {name: 'Chalin', age: 26}
router.put('/', (ctx) => {
  ctx.body = {status: 'success'}
app.use(router.routes(), router.allowedMethods())


Use a customized authorizer

This package provides BasicAuthorizer, it uses HTTP Basic Authentication as the authentication method. If you want to use another authentication method like OAuth, you needs to extends BasicAuthorizer as below:

class MyAuthorizer extends BasicAuthorizer {
  // override function
  getUserName () {
    const { username } = this.ctx.state.user
    return username

  newEnforcer: async () => {
    // load the casbin model and policy from files, database is also supported.
    const enforcer = await casbin.newEnforcer('examples/authz_model.conf', 'examples/authz_policy.csv')
    return enforcer
  authorizer: (ctx, option) => new MyAuthorizer(ctx, option)

How to control the access

The authorization determines a request based on {subject, object, action}, which means what subject can perform what action on what object. In this plugin, the meanings are:

  1. subject: the logged-on user name
  2. object: the URL path for the web resource like "dataset1/item1"
  3. action: HTTP method like GET, POST, PUT, DELETE, or the high-level actions you defined like "read-file", "write-blog"

For how to write authorization policy and other details, please refer to the Casbin's documentation.

Getting Help


This project is licensed under the Apache 2.0 license.