Contracts signed on your own server: DocuSeal is the most feature-complete open-source, self-hosted alternative to DocuSign. A WYSIWYG builder turns any PDF into a fillable form with 14 field types: signature, initials, date, file upload, checkbox, dropdown, radio, stamp, and more. Documents route to multiple submitters in sequence or parallel, with automated SMTP email notifications, reminders, and a mobile-optimized signing experience that works on any device without an account. Every completed document carries an automatic PDF eSignature with verification and an audit trail. Templates are reusable and can also be generated programmatically - from HTML via API or from PDFs and DOCX files with embedded field tags - and the REST API plus webhooks drive full workflow automation, with embedded signing forms and form builders for React, Vue, Angular, and plain JavaScript. Files store on disk or in S3, Google Cloud Storage, or Azure. The UI ships in 7 languages with signing in 14. Runs on SQLite, PostgreSQL, or MySQL; AGPL-3.0 licensed with unlimited documents and no per-signature fees.

With 6,700 GitHub stars, 79 releases, and 40 contributors since its October 2023 launch, OpenSign delivers a fully free electronic signature platform that removes the per-envelope pricing and seat limits of commercial e-signing services. The React-based frontend provides a drag-and-drop interface for placing signature fields, initials, date stamps, text inputs, and checkboxes onto PDF documents, while the Parse Server backend built on Node.js handles document routing through configurable multi-signer workflows with sequential or parallel signing order. Guest signers authenticate via one-time-password email verification without requiring account creation, while registered users manage documents through OpenSign Drive — a centralized vault with folder organization and status tracking across draft, in-progress, completed, and declined states. Every signing action generates tamper-proof audit trails logging timestamps, IP addresses, email addresses, and phone numbers, culminating in a detailed completion certificate attached to the finished document. The REST API v1.2 exposes endpoints for document creation, template dispatch, self-signing, and real-time webhook notifications on document lifecycle events, with regional deployments available in US and EU. PDF templates with pre-placed widgets enable repeated dispatch to different signers in a single API call. Custom branding controls email invitation templates, signing page appearance, and completion certificate styling. Deploy via Docker Compose with MongoDB, Caddy reverse proxy, and automatic HTTPS provisioning. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3 licensed.