How to Add E-Signatures to Your Rork App

Rork builds production-ready React Native apps from a prompt. You describe what you want, it generates a working iOS and Android app. But when that app needs to send contracts, collect signatures, or handle compliance documents, you need something purpose-built for that. Firma.dev connects to Rork apps through a lightweight serverless backend, giving your mobile app a complete e-signature system without bolting on an expensive enterprise tool.

How it works (the short version)

Rork apps are frontend-only, which means you can't call external APIs directly from the app without exposing your credentials in the app bundle. So the integration uses a lightweight backend, typically a Supabase Edge Function or Vercel serverless function, that sits between your Rork app and the Firma.dev API.

The flow is straightforward: your mobile app sends a request to your backend, the backend calls Firma.dev to create a signing request, and the signer recieves the document via email or directly inside your app through an embedded WebView. When the document is signed, Firma.dev sends a webhook to your backend so you can update your database or trigger a push notification.

If you're already using Supabase as your Rork app's backend (which many Rork developers do), you can reuse that same infrastructure. One Edge Function, one secret, and you're live.

Under the hood

For developers who want to understand the architecture before jumping into the docs:

The integration has three parts. First, a backend endpoint (Supabase Edge Function is the recommended path) that stores your Firma.dev API key as a secret and exposes a send-signing-request function. This function calls Firma.dev's create-and-send endpoint with template and recipient details, then returns the signing request ID to your mobile app.

Second, a React Native WebView component that loads Firma.dev's embedded signing URL using the signing_request_user_id from the API response. This lets signers complete the document without leaving your app. You install react-native-webview via Expo, point it at https://app.firma.dev/signing/{id}, and the signing experience renders natively in your mobile UI.

Third, a webhook handler (another Edge Function, deployed with --no-verify-jwt) that listens for events like signing_request.completed and updates your database or sends push notifications accordingly.

You can also connect Firma.dev's Docs MCP server to your AI coding tools while building, so your assistant can reference the full API documentation as it generates integration code for your Rork app.

What you get

Once connected, your Rork app can send documents for signature from any template you've built in Firma.dev, embed the signing experience directly in a mobile WebView, track signing status through webhooks, and trigger downstream actions like push notifications when documents are completed.

Every signature is legally binding under the ESIGN Act, UETA, and eIDAS (SES and AdES). All document data is stored in the EU on AWS infrastructure in Paris and Stockholm.

If you're building a multi-tenant product, Firma.dev's Customer Workspaces give each of your customers their own isolated signing environment with separate templates and usage tracking.

Pricing that works for mobile apps

Most e-signature providers charge per user per month, which makes zero sense for a mobile app where signing is one feature among many. Firma.dev charges €0.029 (roughly 3 cents USD) per envelope. No monthly fees, no per-user charges, no contracts. You ship the feature and only pay when envelopes actually get sent.

For a Rork app that's just getting traction, that means you can launch with e-signatures on day one without committing to a $300/month SaaS contract you might not need yet.

Get started

The full Rork integration guide on docs.firma.dev walks through every step: setting up your backend endpoint, calling it from your React Native code, embedding the signing WebView, and handling webhooks. If you've shipped a Rork app with a Supabase backend before, you'll have signing requests running in under an hour.

Get started with Firma.dev for free, no credit card required.