Firma.dev

Firma.dev is a REST API for embedding electronic signatures into your own product. It covers the full signing lifecycle: an embeddable template editor so users can design documents from inside your app, an embeddable signing experience for signers who sign without leaving your interface, plus standard email-based signing requests for cases where you'd rather send signers a hosted link. It also includes customer workspaces for clean per-customer data separation, and webhooks for every signing event.

It supports PDF and DOCX uploads with automatic server-side conversion, a full audit trail with timestamps and IP addresses, and white-labeling so the signing flow looks like your product, not a third party's.

Pricing is pay-as-you-go at just €0.049 per envelope (about 5 cents USD), with no monthly fees, no contracts, and no per-seat pricing. It's designed to support compliance with the ESIGN Act, UETA, eIDAS (SES and AdES), GDPR and HIPAA, and runs on AWS infrastructure in the EU (Paris region) that maintains SOC 2 and ISO 27001 certifications.

Typical use cases include SaaS companies embedding signing into their own product, agencies sending contracts across many clients, and businesses that want a simple way to get their own paperwork signed without building an in-house solution.