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The MySign API puts envelopes, templates, webhooks and an MCP server behind one clean REST interface: documented properly, hosted entirely in the UK, and part of the Enterprise plan.

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REST API · Webhooks · MCP server · Enterprise plan

app.js

201 Created

const envelope = await mysign.envelopes.create({
  template_id: '01ABCD...',
  merge_data: {
    COMPANY_NAME: 'Acme Corp'
  },
  signatory: {
    name: 'John Doe',
    email: '[email protected]'
  }
});

// ✓ Envelope created and ready to send

Bearer-token authentication, organisation-scoped

Webhooks signed with HMAC-SHA256

Every envelope sealed with an audit certificate

Documentation

Everything documented. Nothing buried.

REST · v1

API reference

Endpoints, parameters and responses for creating and managing signing envelopes programmatically, with worked examples for every call.

Read the reference Bearer tokens

Authentication

How to create organisation-scoped API tokens, use them in every request, and keep them out of your codebase.

Get a token HMAC-SHA256

Webhooks

Real-time envelope events, signed payloads, verification examples and the retry schedule, so you never have to poll.

Wire up events Status codes

Errors

Every HTTP status and error code the API returns, plus handling patterns that fail gracefully instead of loudly.

Handle failures

MCP server · Enterprise

Your AI assistant has a pen.

MySign ships a Model Context Protocol (MCP) server, so assistants like Claude and Copilot can work with your documents the same way your code does. No scraping, no screen-driving, no guesswork.

Prepare envelopes, fill templates and check signing status on your behalf
Assistants act through API keys you issue and revoke. You stay in control
Every envelope an assistant touches keeps its full audit trail

MCP, the REST API and webhooks are part of the Enterprise plan: £299.99/mo, or £239.99/mo billed annually. One flat price, never per user.

See Enterprise pricing Talk to sales

MCP session

Enterprise

> prepare_envelope template: consultancy_agreement

> fill_template merge fields: 6 of 6

> send_for_signature recipients: 2

> check_status status: completed

■ audit certificate issued · sha-256

The assistant does the admin. The audit trail does the remembering. You do neither.

Send it. Sign it. Sorted.

Ready when you are.

Send your first document in the next five minutes. Feel what leaving the big names behind is like.

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From £9.99/month · 7-day free trial for individuals · Cancel anytime · UK support