Undersign
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v1.1
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API Reference Overview
API Reference

Build signing workflows with the Undersign API

Use the Undersign API to create signature requests, work with reusable templates, retrieve signing status and connect electronic-signature workflows to your applications.

Base URL https://toolkit.undersign.app/api/v1.1

New to the API? Start with the Quickstart. Create your API credentials, make an authenticated request, create a signature request and retrieve its status.

Start here

Quickstart

Go from API credentials to your first signature request. Follow the complete request flow with working examples.

Authentication

Learn how API requests are authenticated and how to pass your credentials securely.

Create a signature request

Create a signing request using a reusable template, add signers and send the request.

Core concepts

Signature Requests

A signing transaction created through the API.

Templates

Reusable document configurations containing signer roles and signable fields.

Signers

Recipients participating in the signing workflow.

Prefill Fields

Fields populated by the sender before signing.

External IDs & Metadata

Connect Undersign requests with records in your own application.

API Reference

Signature Requests

Create and retrieve signing requests.

Templates

Retrieve templates and their detailed field configuration.

Categories

Retrieve template categories.

Build event-driven workflows

Webhooks receive notifications associated with signing activity instead of relying only on repeated status checks.

Examples

cURL

Interact with the API from the command line.

PHP

Call the API from server-side PHP.

JavaScript

Call the API from Node.js.

Python

Call the API from Python.

Integration Examples

Ready-to-adapt recipes for common workflows.

Reference

Can't find what you need?

Check Troubleshooting or contact Undersign support with the API request_id when available.