eSignature API

G2 Crowd Leader in UK eSignature

Developing an eSignature integration has never been easier. Legalesign uses a RESTful API that gives developers easy access to all the key functionality of our secure, reliable eSignature platform.

Flexible architecture allows total control of PDFs, sent documents, workflows, groups and users. Built for scalability, our digital signature API is structured around groups/teams, simple to implement but with the flexibility to describe many organisational systems.

Straightforward and accessible for rapid deployment; affordable for occasional or volume use. Our eSignature API pricing plan comes with full documentation (including an OpenAPI schema, with a quick install into Postman), along with patching, support and monitoring as standard.

Whether you're using PDFs or creating from scratch with HTML, all documents on Legalesign end up as Certified PDFs, so you and your clients get peace of mind with tamper-proof documents.

Visit our developer portal below to begin exploring the Legalesign electronic signature API, or check out some of the open-source work that developers have done with our API in Node.js and PHP via the links below.

Developer Portal


The eSignature Process
ISO 27001 Certified Crown Commercial Supplier Advanced Electronic Signature
Users love Legalesign on G2 Legalesign recognized in E-Signature based on user reviews Capterra Legalesign reviews Read Legalesign reviews on G2 Crowd
"I am definitely planning on using the Legalesign e-Signature API again soon. I appreciated the support and attention to security." Arthur King, Head of IT,
"Integrating Legalesign via its API into a customers solution worked flawlessly. The attention to detail within the front end of the product is great and the backend API is equally thought through. Any questions that I did have were answered very quickly and thoroughly...The quality of integration is great, and if you have specific features you need I would highly recommend partnering with Legalesign." Trevor Gildesleeve, Cloudbase Software Inc.
"Using the Legalesign API is a breeze, sending and processing e-signed documents couldn't be easier" James, Director of Information Systems, Ready Project