Model Context Protocol (MCP)

MCP works like a USB port for AI: it provides a standard way for AI agents to plug into external services without custom integration code. An MCP server exposes 'tools' — functions the AI can call — along with descriptions of what they do and what parameters they accept.

For e-signatures, an MCP server lets AI agents like Claude, Cursor, and Windsurf send documents for signing through natural language commands. Instead of the developer writing API integration code, the AI agent calls the MCP tool directly.

Example: A user tells Claude 'Send an NDA to bob@acme.com', and Claude uses the Signbee MCP server's send_document tool to create and send the document — no code needed.

As of April 2026, there are 8 MCP servers offering e-signature capabilities, making document signing one of the most competitive MCP categories.