Fixie gives your Lovable app a static outbound IP address so it can call APIs, webhooks, and internal tools that require IP whitelisting.

Lovable apps run their backend logic as Supabase Edge Functions, which use a dynamic range of outbound IP addresses by default. That's a problem if you're integrating with a third-party API, corporate firewall, or partner system that only accepts traffic from an approved IP list. Routing those specific outbound calls through Fixie means the destination sees a fixed Fixie IP address instead of a changing Supabase IP.

This guide doesn't use the Supabase CLI or dashboard. Everything happens inside Lovable, using prompts and its built-in Secrets panel.

This page is for HTTP and HTTPS requests from a Lovable app. For raw TCP connections like databases, use Fixie Socks instead.

Create a Fixie HTTP/S proxy

Create a Fixie account and create a new Proxy Application, then open the proxy's Details page to copy your proxy URL. It will look like:

http://fixie:YOUR_TOKEN@YOUR_SUBDOMAIN.usefixie.com:80

Pick your Fixie proxy's region (US or EU) before creating it, matching wherever your Lovable project is deployed for lowest latency. Region can't be changed after a proxy is created; if you picked the wrong one, create a new proxy in the correct region instead.

Each Fixie proxy group has two static IP addresses, listed on the same Details page. Add both to the allowlist on the third-party API or firewall you're integrating with.

Add the Fixie URL as a secret in Lovable

• Open your Lovable project and go to the Cloud tab
• Go to Secrets
• Add a new secret named FIXIE_URL
• Paste in your Fixie proxy URL as the value and save

This makes FIXIE_URL available to your project's backend functions without ever putting the proxy URL (or its credentials) in your source code or chat prompts.

Ask Lovable to route a request through Fixie

Whichever backend function makes the outbound call you want on a static IP, describe the change in a prompt rather than editing code directly. For example:

Update the [name] backend function so its request to [destination URL] goes through an HTTP proxy. Read the proxy URL from the FIXIE_URL secret and use Deno.createHttpClient with that proxy URL to create the client used for the fetch call.

Lovable will edit the underlying Supabase Edge Function to create a proxy-aware client with Deno.createHttpClient and pass it into fetch, roughly:

const client = Deno.createHttpClient({
  proxy: { url: Deno.env.get("FIXIE_URL")! },
});

const response = await fetch("https://api.example.com/endpoint", { client });

Only requests made with this client are routed through Fixie. Any other request in the same function still leaves from Supabase's normal, changing IP range, so be specific in your prompt about which call needs the static IP if the function makes more than one.

Verify the static IP

Publish your changes, then trigger the function from your app (for example, click the button or run the flow that calls it) and check what IP the destination actually sees.

Troubleshooting Lovable static IP requests

If the destination still sees the wrong IP address:

• Confirm FIXIE_URL is set under the Cloud tab's Secrets panel in the same Lovable project, and that your latest changes have been published.
• Confirm the function was actually updated to use Deno.createHttpClient. Open Code view in Lovable, use the search tool (Cmd/Ctrl+F or the file search) to look for createHttpClient in your edge function, and check that the client it returns is passed into the fetch call, not just created and left unused.
• Confirm both Fixie static IP addresses (not the proxy hostname) are on the destination's allowlist, the hostname resolves to a load balancer, not the static IPs directly.