OpenSign

OpenSign is an open source document e-signing application, positioned as a DocuSign alternative. It lets users sign, organize, share, and deliver PDF documents, and can run as a hosted free version or on your own server.

Documents can be annotated with hand-drawn, uploaded image, typed, and saved signatures. It supports Sign yourself, reusable templates, one-click signatures, multi-signer invitations with shared links and enforced signing sequence, email OTP verification for guest signers, expiring documents, signer rejection with a reason, and the OpenSign Drive document vault.

It records audit trails with time-stamps, IP addresses, emails, and phone numbers, and generates a completion certificate when a document is finished. It offers an API and integrations with cloud storage, CRMs, and Zapier. Self-hosting uses Docker Compose; the default MongoDB instance is not persistent, so supply a MongoDB URL to retain data.