APISign

What the APISign MCP server does

The APISign MCP server gives an AI agent access to an organization's e-signature workflow.

Templates can be listed, inspected, created, edited, uploaded from base64-encoded DOCX or DOC files, and archived. Contracts can be listed with an optional status filter and retrieved with signer identities and signing states. Agents can also create contracts, change draft details or signers, send documents for signature, and cancel drafts or sent contracts.

The service is scoped to the organization associated with the API key. Sending a contract emails its signers and charges the account balance, so write access should be granted deliberately.

How it works

The APISign MCP server is hosted at https://apisign.io/mcp; it is not installed or self-hosted from this repository. Clients connect using the Streamable HTTP transport and provide the API key in the x-api-key request header.

Templates use Markdown with Handlebars-style variables such as {{client_name}} and {{effective_date}}. When creating a contract, the agent supplies values for those variables. Signature placeholders use the same pattern: a single-signer document can use {{signature}}, while documents with multiple signers can assign separate signature fields through signer_fields.

A typical workflow is to find a template with template_list, inspect its variables with template_get, create a contract with its signers, and then call contract_send. The returned contract ID can be used with contract_get to check the contract and signer statuses.

Setup and configuration

Create an API key in APISign under Account → API Keys. The key is displayed once. A Read Only key permits listing and reading templates and contracts; write tools are not included in the server's tool discovery response. A Read & Write key also permits changes and contract sending.

Add the hosted endpoint to an MCP client with a command such as:

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

Manual configuration uses the following structure:

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

The documented client locations include Claude Desktop configuration files, Cursor's MCP configuration, and ChatGPT's MCP server settings. Keep the API key private and choose the narrowest permission needed.

Tools and capabilities

The APISign MCP server exposes twelve tools:

• template_list and template_get read organization templates.
• template_create, template_update, template_upload, and template_archive manage templates.
• contract_list and contract_get read contracts and signer status.
• contract_create creates a contract from a template or raw content.
• contract_update changes draft contract details or signers; it does not apply to completed or otherwise non-draft contracts.
• contract_send emails signers and bills the account for the document.
• contract_cancel cancels a draft or sent contract.

The repository also contains discovery metadata for the official MCP registry, Agent Plugins clients, and Glama. APISign publishes unauthenticated server-card endpoints for directory discovery.