Comparison
OpenSign vs Signbee
OpenSign is free and community-driven. Signbee is free-tier and professionally managed.
Quick comparison
| OpenSign | Signbee | |
|---|---|---|
| Best for | Organisations with zero software budget, existing infrastructure, and tolerance for community-dependent support | Simplest API for developers + AI agents |
| Pricing | Completely free | Free — 5 docs/month |
| Time to first doc | Minutes to hours | Under 60 seconds |
| Document input | Templates / PDF upload | Markdown or PDF URL |
| Auth | OAuth / API key | API key or none (OTP) |
| AI agent support | — | MCP + Agent Skill + llms.txt |
What is OpenSign?
OpenSign is a purely community-driven, free, self-hosted e-signature solution. It provides full REST API access, cryptographic signing across jurisdictions, and an 'OpenSign drive vault' for document storage — all at zero software cost.
Best for: Organisations with zero software budget, existing infrastructure, and tolerance for community-dependent support.
What is Signbee?
Signbee is an API-first document signing service built for developers and AI agents. You POST markdown or a PDF URL, specify sender and recipient, and Signbee handles everything: PDF generation, email verification, signature capture, and SHA-256 certificate delivery. One API call, no templates, no SDK.
Best for: Developers who want the shortest path from code to signed document, and AI agents that need to send contracts autonomously.
→ signb.ee
Where OpenSign wins
- Completely free — zero software cost
- Full REST API access
- Cryptographic signing across jurisdictions
- Secure document vault
- Maximum privacy with self-hosting
Where Signbee wins
- One API call — No templates, no SDK, no webhook setup
- Markdown documents — Write the contract in text, Signbee generates the PDF
- No account required — Sender verifies via email OTP
- AI-native — MCP server, Agent Skill, llms.txt
- Free tier with real documents — 5 docs/month, no credit card
- SHA-256 certificate — Tamper-proof audit trail on every document
OpenSign limitations
- No corporate backing or dedicated support
- Self-hosting required for production
- Community-dependent development pace
- No managed cloud option
- No AI agent integration
Signbee limitations
- Two-party signing only (no multi-signer routing)
- No visual template builder (markdown or PDF URL only)
- No field placement (no drag-and-drop signature boxes)
- Smaller free tier than some competitors
The verdict
Choose OpenSign if your budget is zero and you can manage your own infrastructure. Choose Signbee if you need managed reliability, AI agent integration, and professional backing — the free tier provides 5 documents/month at zero cost.
FAQs
What is the difference between OpenSign and Signbee?
Choose OpenSign if your budget is zero and you can manage your own infrastructure. Choose Signbee if you need managed reliability, AI agent integration, and professional backing — the free tier provides 5 documents/month at zero cost.
How much does OpenSign cost?
Completely free. No subscription, no per-document fees. Self-hosting infrastructure costs (~$20-50/month) are the only expense.
Is Signbee a good alternative to OpenSign?
Yes. Choose OpenSign if your budget is zero and you can manage your own infrastructure. Choose Signbee if you need managed reliability, AI agent integration, and professional backing — the free tier provides 5 documents/month at zero cost. Signbee offers a free tier of 5 documents per month with no credit card required.
Can AI agents use Signbee instead of OpenSign?
Yes. Signbee has native AI agent support via an MCP server, Agent Skill, and llms.txt. AI agents like Claude, Cursor, and Windsurf can send documents for signature with natural language.
Related resources
Try Signbee — free, no credit card.