API Key Authentication

Secure Your API with API Keys

The Zuplo API Gateway protects your backend API from unauthorized access, abuse, and overload. Add API key authentication to your API in minutes.

Secure Access

Authenticate every request before it reaches your backend.

Control Costs

Set rate limits and quotas to prevent runaway usage.

Ensure Reliability

Shield your backend from overload with traffic management.

How it works

The Zuplo API Gateway sits between your clients and your backend, providing a secure layer of protection and control.

Client

Zuplo API Gateway

Customer VPC

Backend

Step-by-step tutorial

It takes only a few minutes to put Zuplo in front of your backend, adding API key authentication, and configuring your origin to trust requests from Zuplo using shared secrets.

Create a Route in Zuplo

First, create a new route in your Zuplo project that will proxy requests to your backend. This route will be the entry point for your API consumers.

Learn how to create routes

📄 OpenAPI native. Import your existing OpenAPI spec to instantly create routes and power your API documentation .

Add API Key Authentication Policy

Add the API Key Authentication policy to your route. This policy validates incoming API keys and ensures only authorized consumers can access your API.

Adding API Key Authentication policy in Zuplo

API Key Authentication docs

🔐 Leaked key? No problem. As a GitHub Secret Scanning partner, Zuplo can automatically revoke exposed keys before they can be exploited.

Add Set Header Policy

Add the Set Header policy to your route. This policy sets the shared secret header on requests to ensure only requests from Zuplo are accepted by your API.

Set Header Policy docs

Secure Your API with the Shared Secret

Configure your backend to validate the shared secret header set by Zuplo. This ensures that only requests coming through your Zuplo gateway are accepted.

ruby

 require "cuba"
require "rack/protection"
require "openssl"

# Middleware to validate shared secret
module ValidateSharedSecret
  def self.call(env)
    request = Rack::Request.new(env)

    secret = request.env["HTTP_X_SHARED_SECRET"]
    expected_secret = ENV["SHARED_SECRET"]

    halt_with_500 unless expected_secret

    halt_with_401("No secret provided") unless secret
    halt_with_401("Invalid secret") unless valid_secret?(secret, expected_secret)

    yield
  end

  def self.halt_with_500
    [500, { "Content-Type" => "application/json" }, [{ error: "Server configuration error" }.to_json]]
  end

  def self.halt_with_401(message)
    [401, { "Content-Type" => "application/json" }, [{ error: message }.to_json]]
  end

  def self.valid_secret?(secret, expected_secret)
    return false if secret.bytesize != expected_secret.bytesize

    secure_compare(secret, expected_secret)
  end

  def self.secure_compare(a, b)
    OpenSSL.fixed_length_secure_compare(a, b)
  end
end

Cuba.define do
  on "protected" do
    on ValidateSharedSecret do
      res.headers["Content-Type"] = "application/json"
      res.write({ message: "Access granted" }.to_json)
    end
  end
end 

Call Your API Through Zuplo

Now you can call your API through Zuplo using an API key. The request will be authenticated at the gateway, and securely forwarded to your backend.

bash

 curl -X GET \
  'https://your-api.zuplo.dev/your-route' \
  -H 'Authorization: Bearer YOUR_API_KEY' 

Ready to secure your API?

Get started with Zuplo for free and add API key authentication to your API in minutes.

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