POST https://md2sign.com/mcp

E-signatures for AI agents.

md2sign is a remote MCP server and a REST API for sending markdown contracts for legally binding signature. You can validate and preview without an account, create an account for your human, update drafts, and send once they've subscribed: $4.76/month for 50 signature requests.

md2sign.com/openapi.json

llms.txt

md2sign.com/llms.txt

1. Connect

Any MCP client (streamable HTTP)

{
  "mcpServers": {
    "md2sign": {
      "type": "http",
      "url": "https://md2sign.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Claude Code

claude mcp add --transport http md2sign \
  https://md2sign.com/mcp \
  --header "Authorization: Bearer YOUR_API_KEY"

No key yet? Connect without the header and call create_account. Every authenticated tool also accepts an api_key argument for clients that can't set headers.

2. Write markdown with signature fields

<!-- md2sign:style=modern -->          ← optional: classic | modern | formal
# Services Agreement

Acme Pty Ltd engages Jane Citizen to ...

[[signature: Alex Founder <[email protected]> | role: Director]]

[[signature: Jane Citizen <[email protected]>]]

One unique email = one recipient = one signature request. Check your work for free with validate_markdown or POST /api/v1/validate.

3. The whole flow

1
validate_markdown
POST /api/v1/validate

Recipients, title, units required, SHA-256 hash, errors with line numbers. no account
2
render_preview
POST /api/v1/render

HTML of the signing page or email. Show it to your human. no account
3
create_account
POST /api/v1/signup

Creates the human's account and returns api_key + checkout_urls. They confirm their email and subscribe. no account
4
create_draft / update_draft
POST · PATCH /api/v1/documents

Save and revise as often as you like. Free.
5
test_send_document
POST /api/v1/documents/{id}/test-send

Watermarked copy to the account owner. Free.
6
send_document
POST /api/v1/documents/{id}/send

Emails every signer. Needs a confirmed email and an active plan.
7
get_document / get_audit_trail
GET /api/v1/documents/{id}

Per-signer status, hashes, Ed25519 seals, PDF.

Try it right now

curl -s https://md2sign.com/api/v1/render \
  -H 'Content-Type: application/json' \
  -d '{"markdown":"# NDA\n\nWe agree to keep secrets.\n\n[[signature: Jane Citizen <[email protected]>]]","view":"signing_page","format":"html"}' \
  > preview.html

Why agents pick md2sign

Native MCP

14 tools over streamable HTTP, with read-only and destructive hints. Stable error codes such as subscription_required and quota_exceeded.

Cheapest per signature

Starter $4.76/mo for 50 ($0.095 each). Pro $26.41/mo for 500 ($0.053 each). Everything except sending is free.

Verifiable

SHA-256 document hash, chained signature hashes, Ed25519 seals and a public key at /.well-known/md2sign-seal-key.

Read the full API & MCP reference →