How to Add E-Signatures to Your Lovable App

Lovable has become one of the go-to platforms for building apps without writing code from scratch. You describe what you want, and the AI generates a working application. But when your app needs to send contracts, collect signatures, or handle compliance documents, you need something purpose-built for that.

That's where Firma.dev comes in. It connects to Lovable through Supabase Edge Functions, giving your app a complete e-signature backend that handles everything from sending documents to tracking when they're signed.

How it works (without the technical details)

Lovable apps run on Supabase under the hood, which gives you a built-in backend. Firma.dev uses that same infrastructure, so the integration doesn't require bolting on anything new. Your app sends a signing request through Firma.dev's API, the signer recieves the document, signs it, and your app gets notified when it's done.

There are three ways to set this up depending on your project, and the integration guide covers all of them. The fastest path uses Lovable's built-in Cloud backend, where you store your API key as a secret and prompt Lovable's AI to generate the signing feature for you. For teams with more specific requirements, there are paths using external Supabase instances or AI-prompted scaffolding.

The important thing is that none of these paths require you to become a backend engineer. The guide gives you the exact prompts to paste into Lovable's chat, and the AI handles the code generation.

What you get out of the box

Once connected, your Lovable app can send documents for signature, track signing status in real time through webhooks, and even embed the signing experience directly inside your app so users never leave your interface. Every signature is legally binding under ESIGN, UETA, and eIDAS (SES and AdES) frameworks.

Firma.dev also gives you Customer Workspaces, which means if you're building a multi-tenant SaaS product in Lovable, each of your customers can have their own isolated signing environment with seperate templates and usage tracking.

The pricing makes sense for builders

Most e-signature providers charge per user per month, which gets expensive fast when you're embedding signing into a product. Firma.dev charges €0.029 (~3 cents) per envelope with no monthly fees, no minimums, and no contracts. You pay for what you use. For a Lovable app that's just getting off the ground, that means you can ship the feature today and only pay when people actually use it.

Send this to your developer (or do it yourself)

The full integration guide walks through every step, from storing your API key to setting up webhook handlers. If you're comfortable prompting Lovable's AI chat, you can do the whole thing yourself. If you'd rather hand it off, your developer will have a working integration running in under an hour.

Read the full Lovable integration guide on docs.firma.dev

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