flask-limiter's Introduction

Flask-Limiter

Flask-Limiter provides rate limiting features to flask applications.

It allows configuring various backends to persist the rate limits, which is provided by the limits library.

Quickstart

Add the rate limiter to your flask app. The following example uses the default in memory implementation for storage.

from flask import Flask
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address

app = Flask(__name__)
limiter = Limiter(
    app,
    key_func=get_remote_address,
    default_limits=["2 per minute", "1 per second"],
)

@app.route("/slow")
@limiter.limit("1 per day")
def slow():
    return "24"

@app.route("/fast")
def fast():
    return "42"

@app.route("/ping")
@limiter.exempt
def ping():
    return 'PONG'

app.run()

Test it out. The fast endpoint respects the default rate limit while the slow endpoint uses the decorated one. ping has no rate limit associated with it.

$ curl localhost:5000/fast
42
$ curl localhost:5000/fast
42
$ curl localhost:5000/fast
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>429 Too Many Requests</title>
<h1>Too Many Requests</h1>
<p>2 per 1 minute</p>
$ curl localhost:5000/slow
24
$ curl localhost:5000/slow
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>429 Too Many Requests</title>
<h1>Too Many Requests</h1>
<p>1 per 1 day</p>
$ curl localhost:5000/ping
PONG
$ curl localhost:5000/ping
PONG
$ curl localhost:5000/ping
PONG
$ curl localhost:5000/ping
PONG