express-limit 

_express-limit_ is a small project that add rate limitations to your API.

Installation

``console
npm install --save express-limit
`

Usage

`js
const limit = require("express-limit").limit;

app.get(
"/api/users",
limit({
max: 5, // 5 requests
period: 60 * 1000, // per minute (60 seconds)
}),
function (req, res) {
res.status(200).json({});
}
);
`

Options

`js
{
(max = 60), // Maximum request per period
(period = 60 * 1000), // Period in milliseconds
(prefix = "rate-limit-"), // Prefix of the key
(status = 429), // Status code in case of rate limit reached
(message = "Too many requests"), // Message in case of rate limit reached
(identifier = (request) => {
// The identifier function/value of the key (IP by default, could be "req.user.id")
return request.ip || request.ips; // Read from Default properties
}),
(headers = {
// Headers names
remaining: "X-RateLimit-Remaining",
reset: "X-RateLimit-Reset",
limit: "X-RateLimit-Limit",
}),
(store = new Store()); // The storage, default storage: in-memory
}
`

In some cases, you could want to skip the limitation you made for trusted client.
In this case, you can add a special field in the request object:

`js
req._skip_limits = true;
`

Also, you could want to add specific limitations for a special client.
In this case, you can add a special field in the request object:

`js
req._custom_limits = {
max: 1000, // 1000 requests
period: 60 * 1000, // per minutes
};
`

Just don't forget where you place this modification! It could be applied for all routes!

Available Stores

Actually, two stores have been made:

- InMemoryStore (default store, nothing to do)

`js
const RateLimiter = require("express-limit").RateLimiter;
const InMemoryStore = require("express-limit").InMemoryStore;

const store = new InMemoryStore();

const limit = (options = {}) => {
options.store = store;

return new RateLimiter(options).middleware;
};

app.get(
"/api/users",
limit({
max: 5, // 5 requests
period: 60 * 1000, // per minute (60 seconds)
}),
function (req, res) {
res.status(200).json({});
}
);
`

- RedisStore

`js
const redis = require("redis");
const client = redis.createClient();

const RateLimiter = require("express-limit").RateLimiter;
const RedisStore = require("express-limit").RedisStore;

const store = new RedisStore(client);

const limit = (options = {}) => {
options.store = store;

return new RateLimiter(options).middleware;
};

app.get(
"/api/users",
limit({
max: 5, // 5 requests
period: 60 * 1000, // per minute (60 seconds)
}),
function (req, res) {
res.status(200).json({});
}
);
`

- RedisLegacyStore (node-redis v3 or node-redis v4 with legacyMode true)

`js
const redis = require("redis");
const client = redis.createClient({
legacyMode: true,
});

const RateLimiter = require("express-limit").RateLimiter;
const RedisLegacyStore = require("express-limit").RedisLegacyStore;

const store = new RedisLegacyStore(client);

const limit = (options = {}) => {
options.store = store;

return new RateLimiter(options).middleware;
};

app.get(
"/api/users",
limit({
max: 5, // 5 requests
period: 60 * 1000, // per minute (60 seconds)
}),
function (req, res) {
res.status(200).json({});
}
);
``

Keep in touch!