OpenSignLabs/OpenSign
OpenSign
OpenSign is a self-hosted, open-source document signing platform that enables users to send, sign, and manage PDF documents with digital certificates and encryption. It functions as a complete e-signature solution, allowing organizations to run their own signing service on private infrastructure while maintaining full control over their data and document workflows.
The platform supports sequential multi-signer workflows, where documents can be sent to multiple recipients in a predefined order, with each signer receiving an email-based one-time password for verification before accessing the document. Documents are rendered and annotated directly as PDFs, supporting hand-drawn, typed, or uploaded signature images through an advanced signing pad. The system includes a document audit trail that logs all activities with timestamps, IP addresses, and email IDs, and generates completion certificates for signed documents.
OpenSign provides a REST API for integrating signing workflows into existing systems, along with webhook notifications that push real-time document status changes to external services. It connects with cloud storage and CRM platforms through Zapier and other integration tools. The application is deployed as a single Docker container configured entirely through environment variables, with documents stored in any S3-compatible object store and an automatic fallback to local filesystem storage. Users can create and reuse PDF templates, organize documents in folders, manage contacts in an address book, and set document expiration periods with the option for signers to reject signing with a reason.