API Key Authentication

Secure Your Phoenix API with API Keys

The Zuplo API Gateway protects your backend API from unauthorized access, abuse, and overload. Add API key authentication to your Phoenix 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 Phoenix 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 Phoenix 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 Phoenix 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 Phoenix API with the Shared Secret

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

Elixir

 defmodule MyAppWeb.Plugs.ValidateSharedSecret do
  import Plug.Conn
  require Logger

  def init(options), do: options

  def call(conn, _opts) do
    case System.get_env("SHARED_SECRET") do
      nil ->
        conn
        |> send_resp(500, "Server configuration error")
        |> halt()

      expected_secret ->
        case get_req_header(conn, "x-shared-secret") do
          [] ->
            conn
            |> send_resp(401, "No secret provided")
            |> halt()

          [secret] ->
            if valid_secret?(secret, expected_secret) do
              conn
            else
              conn
              |> send_resp(401, "Invalid secret")
              |> halt()
            end
        end
    end
  end

  defp valid_secret?(secret, expected_secret) do
    Plug.Crypto.secure_compare(secret, expected_secret)
  end
end

# Example usage in a Phoenix Router

defmodule MyAppWeb.Router do
  use MyAppWeb, :router

  pipeline :protected do
    plug MyAppWeb.Plugs.ValidateSharedSecret
  end

  scope "/api", MyAppWeb do
    pipe_through :protected

    get "/protected", ProtectedController, :index
  end
end

defmodule MyAppWeb.ProtectedController do
  use MyAppWeb, :controller

  def index(conn, _params) do
    json(conn, %{message: "Access granted"})
  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 Phoenix 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 Phoenix API in minutes.

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