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REST framework for Node.js, Express and MongoDB


REST framework for Node.js, Express and MongoDB

Arrest lets you write RESTful web services in minutes. It works with Express 4.x, implements simple CRUD semantics on MongoDB and the resulting web services are compatible with the $resource service of AngularJS.

How to Install

npm install arrest

Super Simple Sample

The following sample application shows how to attach a simple REST API to and express application. In the sample, the path /api is linked to a data collection on a MongoDB instance running on localhost:

var arrest = require('arrest')
  , express = require('express')
  , bodyParser = require('body-parser')
  , app = express()
arrest.use(app, '/api', new arrest.RestMongoAPI('mongodb://localhost:27017', 'data'));

Now you can query your data collection like this:

curl "http://localhost:3000/api"

You can add a new item:

curl "http://localhost:3000/api" -d "name=Jimbo&surname=Johnson"

(for complex objects, just do a POST with a JSON body)

You can query a specific item by appeding the identifier of the record (the _id attribute):

curl "http://localhost:3000/api/51acc04f196573941f000002"

You can update an item:

curl "http://localhost:3000/api/51acc04f196573941f000002" "name=Jimbo&surname=Smith"

And finally you can delete an item:

curl "http://localhost:3000/api/51acc04f196573941f000002" -X DELETE

To use this REST service in an AngularJS application, all you need to do is to include the ngResource service and, in a controller, create a $resource object:

var api = new $resource('/api/:_id', { _id: '@_id' }, {});
$ = api.query();

Default API routes

By default, each time you call arrest.use specifying a different path, the following routes are added to your Express app:

app.get('/path', arrest.RestAPI._query);
app.get('/path/:id', arrest.RestAPI._get);
app.put('/path', arrest.RestAPI._create);'/path', arrest.RestAPI._create);'/path/:id', arrest.RestAPI._update);
app.delete('/path/:id', arrest.RestAPI._remove);

Creating a custom API

To create a custom API, start by defining a sub class of RestMongoAPI (or RestAPI if you don't need MongoDB support):

var util = require('util')
  , arrest = require('arrest')
function MyAPI() {, 'mongodb://localhost:27017', 'my_collection');
util.inherits(MyAPI, RestMongoAPI);

You can now customize, for example, how the queries on the entire collection are performed: the following example checks that a query parameter q is passed to the web service:

MyAPI.prototype._query = function(req, res) {
  if (!req.query.q) {
    arrest.sendError(res, 400, 'q parameter is missing');
  } else {
    this.query({ name: req.query.q}, arrest.responseCallback(res));

To add a new web services, modify the routes array, adding the required entries. The array contains objects with to following format:

  method: 'get|post|put|patch|delete|any other valid http method',
  mount: '/path/to/the/new/webservice/:with/:needed/:paramenters',
  handler: this.handler_function }

The default routes are:

  { method: 'get',    mount: '',     handler: this._query },
  { method: 'get',    mount: '/:id', handler: this._get },
  { method: 'put',    mount: '',     handler: this._create },
  { method: 'post',   mount: '',     handler: this._create },
  { method: 'post',   mount: '/:id', handler: this._update },
  { method: 'delete', mount: '/:id', handler: this._remove }

For example:

function MyAPI() {, 'mongodb://localhost:27017', 'my_collection');
  this.routes.push({ method: 'get', mount: '/greet/:name', handler: this._hello });
util.inherits(MyAPI, arrest.RestMongoAPI);
MyAPI.prototype._hello = function(req, res) {
  res.jsonp({ hello: });

And, as a last step, remember to use the new API:

arrest.use(app, "/api", new MyAPI());