Show HN: Signbee – An API that lets AI agents send documents for signature

3 comments

• mjcbeckett 13 hours ago

  Hi HN,

  I built Signbee while working on AI agents that handle contracting workflows.

  The agents could draft agreements, negotiate terms, manage deals — but the moment a signature was needed, the workflow broke. It always ended with "please upload this to DocuSign" — which meant human intervention, account setup, and manual uploads.

  So I built a simple API. You POST markdown and Signbee generates the PDF, or you pass a URL to your own PDF if you already have one designed the way you want it.

  No templates, no editor. Either way, it verifies both parties via email OTP and produces a signed document.

    curl -X POST https://signb.ee/api/v1/send \
      -H "Content-Type: application/json" \
      -d '{
        "markdown": "# NDA\n\nTerms...",
        "sender_name": "You",
        "sender_email": "you@company.com",
        "recipient_name": "Client",
        "recipient_email": "client@co.com"
      }'
  

  Under the hood: - Markdown → PDF generation, or bring your own PDF via URL - Both parties verified via email OTP - Timestamps and IP addresses recorded - Final document hashed with SHA-256 - Certificate page appended with full audit trail

  One interesting challenge: the certificate page itself is part of the document that gets hashed, so any modification — even to the certificate — invalidates the integrity check.

  I also built an MCP server (npx -y signbee-mcp) so tools like Claude or Cursor can call it directly.

  Curious to hear from people who've dealt with document signing systems or automated agent workflows — what would you want to automate?

• jameswondere007 11 hours ago

  interesting and useful, i will really try this

  [-]
  • mjcbeckett 11 hours ago

    Thanks! If you run into anything or have questions about the API, happy to help. The quickest way to try it is the curl example in my comment above — no signup needed.