Making API requests with a static IP from a Node app on Sevalla

Recommended setup

Use Fixie HTTP/S proxy for HTTP and HTTPS requests to an API, webhook provider, or service that allowlists outbound IP addresses. Store the proxy value in FIXIE_URL, then configure Node.js to route outbound traffic through Fixie before connecting to API allowlisting.

Set up Fixie on Sevalla

Create a Fixie HTTP/S proxy in the Fixie dashboard. Copy the proxy value into Sevalla environment variables as FIXIE_URL, and copy the outbound IPs into the destination allowlist.

Implementation

The example below shows the core application-side change. Keep credentials in environment variables and avoid committing proxy, database, or API secrets.

Make an HTTP request through FIXIE_URL

const axios = require('axios');

const fixieUrl = new URL(process.env.FIXIE_URL);

axios.get('https://api.example.com/data', {
  proxy: {
    protocol: 'http',
    host: fixieUrl.hostname,
    // URL drops default ports, so fall back to 80 for Fixie's standard proxy port.
    port: Number(fixieUrl.port) || 80,
    auth: {
      username: fixieUrl.username,
      password: fixieUrl.password,
    },
  },
}).then((response) => {
  console.log(response.status);
});

Good to know

• Sevalla builds Node apps with Nixpacks by default, so no Dockerfile changes are needed, just the environment variable.
• Setting it from the CLI looks like sevalla apps env-vars create <app-id> --key FIXIE_URL --value "<proxy-url>", which keeps the value out of the repo.

Allowlist and test the static IPs

1. Open the Fixie dashboard and copy the outbound IP addresses for this proxy.
2. Add both IPs to the API provider.
3. Deploy the updated Node.js app on Sevalla.
4. Run a small connection test before sending production traffic.

Related guides

• Making API requests with a static IP from a Node app on Heroku
• Making API requests with a static IP from a Node app on Vercel
• Making API requests with a static IP from a Node app on Render
• Making API requests with a static IP from a Node app on Fly.io
• Making API requests with a static IP from a Node app on Koyeb
• Making API requests with a static IP from a Node app on AWS Lambda

Related docs

• Node.js implementation examples
• Sevalla setup documentation
• API allowlisting connection guide