BuiltSign MCP Server

Connect AI assistants like Claude to BuiltSign, the e-signature platform for documents up to 1GB. Upload PDFs, send signing requests, place signature fields, track status and download signed documents, straight from a conversation.

Requirements

• Node.js 18 or newer
• A BuiltSign API key (Enterprise plan): create one under Settings, API Keys in your BuiltSign dashboard
• Tip: use a sandbox API key while testing. Sandbox keys skip real emails and keep test data separated.

Installation

Claude Desktop / Claude Code

Add the server to your MCP configuration (for Claude Desktop: claude_desktop_config.json):

{
  "mcpServers": {
    "builtsign": {
      "command": "npx",
      "args": ["-y", "@builtsign/mcp"],
      "env": {
        "BUILTSIGN_API_KEY": "bs_your_api_key",
        "BUILTSIGN_API_URL": "https://api.builtsign.com"
      }
    }
  }
}

For Claude Code:

claude mcp add builtsign -e BUILTSIGN_API_KEY=bs_your_api_key -e BUILTSIGN_API_URL=https://api.builtsign.com -- npx -y @builtsign/mcp

From source

npm install
npm run build
BUILTSIGN_API_KEY=bs_... BUILTSIGN_API_URL=https://api.builtsign.com node dist/index.js

Environment variables

| Variable | Required | Description | |---|---|---| | BUILTSIGN_API_KEY | Yes | API key with read and/or write scope (bs_...) | | BUILTSIGN_API_URL | Yes | API base URL, e.g. https://api.builtsign.com |

Tools (15)

Documents

• upload_document: upload a PDF from a local path, returns a document_id
• list_documents: list uploaded documents

Signing requests

• create_signing_request: create a draft (signers are not notified yet)
• create_and_send_signing_request: create and send in one step
• send_signing_request: send a draft to all signers
• get_signing_request: status and details, including per-signer progress and signer ids
• list_signing_requests: list with filters, paginate with limit + offset
• cancel_signing_request: cancel a pending request
• send_reminder: remind all pending signers
• download_signed_pdf: presigned URL (24h) for the signed PDF of a completed request
• add_signature_fields: place signature fields (replaces all fields; positions in % of the page)

Templates

• list_templates: list reusable templates
• send_from_template: send a signing request from a template, with role mapping and variables

Events and usage

• list_events: org-wide signing events with cursor pagination
• get_usage: current-period usage and plan limits

Example prompts

• "Upload contract.pdf and send it to [email protected] for signature."
• "Create a draft signing request for offer.pdf with two signers who sign in order: first Anna, then Mark. Place a signature field for each on page 3."
• "Which signing requests are still pending? Send everyone a reminder."
• "The Meridian contract is completed. Give me the download link for the signed PDF."

Notes

• Signers sign in the browser; they never need a BuiltSign account.
• Sequential signing: set signing_order to sequential and give each signer an order (1, 2, ...).
• Creates support an optional idempotency_key so retried calls never produce duplicates.
• Errors return the BuiltSign error message plus a machine-readable code, e.g. Rate limit exceeded (rate_limit_exceeded).

Links

• API documentation
• BuiltSign

MIT License