APISign MCP Server

Send documents out for legally binding e-signature, and manage the templates they come from, directly from an AI agent.

APISign runs a hosted Model Context Protocol server at https://apisign.io/mcp. There is nothing to install and nothing to self-host — point your client at the URL, give it an API key, and your agent can draft a contract from a template, fill its variables, send it to signers, and watch the signatures come in.

This repository holds the connection metadata and client configuration. The service itself lives at apisign.io.

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Connect

1. Get an API key. Sign in at apisign.io, then go to Account → API Keys and create one. Copy it — it is shown once.

Pick the permission deliberately:

Permission	What the agent can do
Read Only	List and read templates and contracts. Nothing else.
Read & Write	Everything, including sending contracts, which charges your balance.

A Read Only key does not merely refuse the write tools — they are left out of the tools/list response entirely, so the agent never learns they exist. If your agent only needs to look things up, use one.

2. Add the server. The quickest route, which works for Claude, Cursor, ChatGPT and most other clients:

npx add-mcp https://apisign.io/mcp --header '{"x-api-key": "your-api-key-here"}'

Or configure it by hand:

{
  "mcpServers": {
    "apisign": {
      "url": "https://apisign.io/mcp",
      "headers": {
        "x-api-key": "your-api-key-here"
      }
    }
  }
}

Client	Config file
Claude Desktop (macOS)	~/Library/Application Support/Claude/claude_desktop_config.json
Claude Desktop (Windows)	%APPDATA%\Claude\claude_desktop_config.json
Cursor	~/.cursor/mcp.json, or %USERPROFILE%\.cursor\mcp.json
ChatGPT	Settings → Features → MCP servers → Add MCP server

Transport is Streamable HTTP. Authentication is the x-api-key header.

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Tools

Twelve tools, in two families. Everything is scoped to the organization the API key belongs to.

Templates

Tool	Access	What it does
template_list	read	List all templates in the organization.
template_get	read	Fetch one template by ID, with its content and field definitions.
template_create	write	Create a blank template from a name and optional Markdown.
template_update	write	Change a template's name, content, or fields.
template_upload	write	Convert a base64-encoded DOCX/DOC into a template.
template_archive	write	Soft-delete a template.

Contracts

Tool	Access	What it does
contract_list	read	List contracts, optionally filtered by status.
contract_get	read	Fetch one contract, including every signer and their status.
contract_create	write	Create a contract from a template or from raw content, with signers.
contract_update	write	Edit a draft contract's details or signers. Drafts only.
contract_send	write	Send a contract for signing. Charges your balance and emails the signers.
contract_cancel	write	Cancel a draft or sent contract.

Templates are Markdown with Handlebars-style variables — {{client_name}}, {{effective_date}} — that contract_create fills in. Signature placeholders work the same way: a one-signer document needs a {{signature}}, and a multi-signer document gives each party their own, assigned through signer_fields.

A worked example

Draft an NDA for Acme Corp from our standard mutual NDA template, effective the first of next month, and send it to [email protected] and to me.

The agent calls template_list to find the template, template_get to read its variables, contract_create to fill them and attach both signers, then contract_send. You get back a contract ID you can follow with contract_get.

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Discovery metadata

File	Consumed by
server.json	The official MCP registry — published as io.apisign/apisign.
plugins/apisign/mcp.json	Cursor and other Agent Plugins clients.
glama.json	Glama's indexer.

The server also serves its own card, without authentication, so directories can describe it without an API key:

• https://apisign.io/.well-known/mcp.json
• https://apisign.io/.well-known/mcp/server-card.json

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Docs and support

• MCP server documentation
• API reference
• Pricing — contracts are billed per document sent

Issues with the MCP integration are welcome here. Questions about your account belong at apisign.io.

License

MIT