OpenSign

OpenSign provides a self‑hosted, open‑source platform for electronic signing of PDF documents. It implements encryption‑based security, supports hand‑drawn, image‑based, typed and saved signatures, and generates completion certificates with access logs. Users can create reusable PDF templates, annotate files, and store signed documents in an integrated vault.

The system allows multiple participants to be invited via signing links, enforces sequential signing when required, and offers OTP‑based email verification for guest signers. Documents can be configured to expire after a set period, and signers may reject a request with a reason that is communicated to the sender. Email notifications use customizable templates.

OpenSign is targeted at individuals and organizations that need a free, subscription‑free alternative to commercial e‑signature services. It can be deployed on‑premises, offers an API for integration, and is released under the AGPL‑3.0 license, positioning it as a stable, community‑driven solution for secure digital agreements.