Supra Code
How a Spanish software studio replaced a planned in-house solution with a Firma.dev integration, and cut the compliance risk entirely.
The Problem
SupraCode builds business software for companies in Spain: CRMs, ERPs, and the document workflows that tie them together. Their clients send a lot of contracts. Employee time-tracking sign-offs, which are legally mandatory in Spain. SEPA direct debit mandates when a client changes their bank account. General agreements that need to reach multiple signers and leave a clear audit trail.
When the team started scoping out e-signature functionality, building something in-house was on the table. They had the technical ability to do it. What they didn't want to take on was the legal surface area that comes with it. GDPR compliance, eIDAS alignment, audit trails that hold up in court — these aren't features you bolt on. For a small studio focused on shipping product for clients, absorbing that compliance burden made no sense.
It's about GDPR and all these rules and requirements that you have to accomplish to be 100% legal. That's something we rejected to do in-house.
— Jose, Developer, SupraCode
The Switch
Jose found Firma.dev and had the integration running in about a day. The implementation wasn't a straightforward frontend drop-in either. SupraCode specifically didn't want the signing flow handled from the client side, so they built a Supabase edge function to handle the Firma.dev API calls server-side. That added some complexity, but the integration still landed inside a single working day.
The workflow they built handles the full document lifecycle. Contracts are generated, sent to all relevant parties for signing, and tracked through to completion. Clients can see exactly when a document was signed or rejected, and by whom — which turns out to be something their customers care about a lot. For employee time-tracking documents, the recieve-and-sign flow runs every week across a 50-person workforce. All of it runs through Firma.dev without any manual steps.
It was like one day. We built an edge function, we didn't want to do it from the front-end side, we wanted it in the edge function of Supabase. We took a little longer because of that, but around one day.
— Jose, Developer, SupraCode
The Results
SupraCode's clients run 50-person teams signing documents every week. At €1 to €3 per envelope with a typical enterprise provider, that's €150 to €600 per month just for weekly employee time-tracking sign-offs, before counting any client-facing documents. At €0.029 per envelope with Firma.dev, the same volume costs under €6.
Beyond the price, the thing that landed best with SupraCode's clients was visibility. Knowing exactly when a document was signed, who signed it, and whether it was rejected gave their clients something they hadn't expected to care about until they had it. For a studio building software that other businesses rely on day to day, that kind of detail matters.
Our client was really happy to know exactly when it was signed, if it was rejected and at what time by the employee or by the client.
— Jose, Developer, SupraCode
Comparison
DocuSign
Firma.dev
GDPR / eIDAS compliance
Must be built and maintained
Yes (€0.029/envelope)
Integration time
Weeks to months
1 day
Per envelope cost
Infrastructure + maintenance
€0.029
Audit trail
Custom build required
Built in
Multi-party signing
Custom build required
Built in
Ongoing compliance updates
Your responsibility
Handled
