inSign Electronic Signature API for Developers

Add eIDAS-compliant electronic signatures (SES, AES, QES) to your application.

EU-hosted. DSGVO / GDPR-ready. Free sandbox with zero setup - no registration, no API key, no credit card.

Learn the API

Step-by-step guide through the core signing workflow. Create a session, upload a PDF, sign it, download the result - all live in the browser against the free sandbox.

New to inSign? Start here. Takes about 5 minutes.

Open Getting Started Guide

Explore the API

Full interactive playground with schema-aware JSON editor, autocomplete, code snippets in 13 languages, webhook viewer, and request tracing. Your complete API reference.

Already know the basics? Dive deeper here.

Open API Explorer

See it in Action

Working demo applications showing real integrations: an embedded signature pad (Node.js) and a full backend integration (Java/Spring Boot). Clone, run, and adapt.

Ready to integrate? Use these as your starting point.

See Demo Apps

Getting Started

API Explorer

Demo App

Production

Where should I start?

Building a web app that needs signatures? Getting Started Guide + Embedded Signature Pad Demo
Building a backend with signature workflows? Getting Started Guide + Java Spring Boot Sample
Evaluating inSign for your team? Getting Started Guide - click through in 5 minutes, live in the browser
Already know the API, looking for a specific field? API Explorer - schema-aware editor with autocomplete from the live OpenAPI spec
Need code snippets in your language? API Explorer, Step 4 - code generation in 13 variants (Java, Python, PHP, C#, Node.js, Go, Rust, ...)

What's in this repository?

Component	What it is	Stack
Getting Started Guide	Interactive 4-step walkthrough of the core signing workflow with live API calls against the sandbox	Browser
API Explorer	Full interactive playground: schema-aware editor, code snippets in 13 languages, webhook viewer, request tracing	Browser
Signature Pad Demo	Broker-mandate signing flow with embedded signature pad. Clone and run - connects to the sandbox out of the box	Node.js Express
Java Sample App	Full backend integration with pluggable API client architecture, SSE events, webhook handling	Java Spring Boot
Postman Collection	Pre-built collection for quick API testing in Postman, pre-configured for the sandbox	Postman

What the API Explorer gives you

The inSign API Explorer is a complete interactive playground. Click any thumbnail below to see it full-size.

**JSON autocomplete and validation** - schema-aware editor with inline suggestions, hover docs, and real-time error highlighting powered by the live OpenAPI spec

**Code generation** - instantly generate ready-to-run code snippets in 13 variants across 11 languages (cURL, Java, Python, PHP, C#, Node.js, TypeScript, Ruby, Go, Rust, Kotlin) including 3 Java flavors

**API call tracing** - full request/response trace log with timing, headers, and status codes for every call you make

**Webhook visualization** - built-in webhook viewer that catches and displays real-time callback events as they arrive from the server

**12 branded test contracts** - professionally designed PDFs with unique company branding, logos, and color schemes - or drag-and-drop your own PDF

**Feature selector** - toggle inSign features like biometric signatures, timestamps, and document options directly from the UI

**CSS customizer** - live theme editor to preview how the inSign signing UI looks with your brand colors

**Dark mode** - full light/dark theme support across the entire explorer

Open API Explorer Explorer Documentation

Java API Library

For Java projects, the insign-java-api library provides a typed client with builders and configuration helpers.

<dependency>
  <groupId>com.getinsign</groupId>
  <artifactId>insign-java-api</artifactId>
</dependency>

Add the GitHub Package Registry to your Maven settings.xml - see Working with the Apache Maven registry.

Demo Applications

Java Spring Boot Sample

Java / Spring Boot / Maven

Full backend integration demonstrating session creation, document upload, external signing invitations, real-time status tracking, webhook handling, and document download. Features a pluggable API client architecture - swap implementations by changing one Maven dependency.

Sandbox — test data only. Public sandbox; documents are readable by anyone. Never enter real personal data.

Key concepts: Pluggable API clients, convention-based JSON mapping, forward-compatible POJO model, SSE real-time events, webhook integration

View on GitHub

cd src/java/app
mvn spring-boot:run -Pspring-client    # Option A: Spring REST client
mvn spring-boot:run -Pinsign-client    # Option B: Java API client
# Open http://localhost:8090

Embedded Signature Pad

Node.js / Express

A realistic broker-mandate signing flow. The user fills in personal data, the server generates a mandate PDF on the fly, creates an inSign session, and the signature pad is rendered inline - all without leaving the page.

Sandbox — test data only. Public sandbox; documents are readable by anyone. Never enter real personal data.

Key concepts: Embedded mode, JWT authentication, ##SIG{...} tags, cookieless browser-to-server communication, dynamic PDF generation with signature fields

View on GitHub

cd src/sign-widget-demo-application
./run.sh              # installs deps if needed, starts the server
# Open http://localhost:3000