Flask Allowed Hosts is a Flask extension that provides host validation for API endpoints. It allows you to enforce that requests are only accepted from specific hosts, providing an additional layer of security for your Flask application.

Install the package using pip:

pip install flask-allowedhosts

To limit access to your routes using flask-allowedhosts follow these simple steps:

1. Import the limit_hosts decorator from flask_allowedhosts.
2. Define the list of allowed hosts.
3. Apply the @limit_hosts decorator to the desired endpoint(s).

from flask import Flask, request, jsonify
from flask_allowedhosts import limit_hosts

app = Flask(__name__)

ALLOWED_HOSTS = ['127.0.0.1', 'localhost']


@app.route("/api/greet")
@limit_hosts(allowed_hosts=ALLOWED_HOSTS)
def greet_endpoint():
    name = request.args.get("name", "Friend")
    greeting = {"greeting": f"Hello There {name}!"}
    return jsonify(greeting), 200


if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)

Now only the allowed hosts set in ALLOWED_HOSTS can access the protected endpoint(s). Requests from other hosts will receive a 403 Forbidden error.

The default value for allowed_hosts is an empty list, which means requests from all hosts are allowed.

Contributions are welcome! If you have any suggestions, bug reports, or feature requests, please open an issue or submit a pull request.

This project is licensed under the [MIT] License - see the LICENSE.md file for details.