LexCallida
LexCallida replaced a modified self-hosted DocuSEAL instance with Firma.dev's e-signature API, getting full white-label customization and competitive pricing without maintaining their own infrastructure.
Customization Was the Dealbreaker
LexCallida is building a SaaS platform for lawyers in Brazil. The application lets attorneys register their lawsuits, track case status across every court in the country, and get notified when deadlines or new filings appear. They also offer an electronic guardian feature that monitors tax IDs for new lawsuits automatically. The product is in advanced development, with heavy testing underway.
Before Firma.dev, Eros Stein had a self-hosted instance of DocuSEAL running with custom modifications. The open source version was free, but the things that actually mattered for a production product were paywalled. Custom branding, company logos, color customization, anything that would make the signing experience feel native to LexCallida's application rather than a third-party tool. Eros had made some modifications himself, but the limitations were real.
Basically, customization. I could not have my own company's logo there. I could also have names and things like that. Colors, things that your software allows us to do, we could not have there.
— Eros Stein, Developer, LexCallida
Built the Integration with AI
Firma.dev's REST API works with any language, so Eros connected it to his C# and .NET stack directly.
The result is an embedded signing experience where users never leave the LexCallida application. That was the whole point. Eros didn't want any branding from DocuSEAL or Firma.dev visible to his end users. The lawyer opens the app, signs a contract with their client, and the entire flow looks and feels like it belongs to LexCallida. With Firma.dev's white-label customization, including colors set directly through the dashboard, he got exactly that.
It's a solution that allowed us to make for the user, to make it look like he never actually left the app. I don't want any information regarding DocuSEAL or Firma or anything. I want the user to feel like, okay, this is the application because this is the application I trust.
— Eros Stein, Developer, LexCallida
Price and Capabilities, Not Just Cost Savings
The switch from DocuSEAL wasn't primarily about saving money. Eros was running his own VPS for the self-hosted instance at roughly $100 a year. For a legal tech platform where contract signing happens per-client rather than in high volume, the raw cost difference isn't dramatic. What changed was the capabilities.
Firma.dev's pricing is competitive at €0.029 per envelope, but the real value for LexCallida is what comes included: full white-label branding, embedded editors, API access, and audit logs. Eros specifically checked the audit trail after signing test contracts, and also built a mirroring layer in his own application as an extra safety net for legal purposes. For a platform serving lawyers, that kind of documentation trail matters.
Your price is very competitive, so that's something we really enjoy. But the biggest thing I would have to say is integration and customization.
— Eros Stein, Developer, LexCallida
Comparison
DocuSign
Firma.dev
White-label branding
Paywalled (Pro license required)
Yes (€0.029/envelope)
Custom colors/logos
Paywalled
Included (dashboard or API)
Per-envelope cost
$0.20/doc via API (Pro) or free without API
€0.029/envelope
Infrastructure
Self-managed VPS required
Fully managed
.NET SDK
Not available
Not available (API works with any language)
Embedded signing editor
Pro license require
Built-in
Audit trail
Basic
Built-in with detailed logs
Ongoing maintenance
Your responsibility
Handled
