Sign Customiser

API reference

Introduction

Copy page

Use the Sign Customiser API to build the backend side of a custom integration: receive the signed product creation callback, return your own product IDs, submit completed orders, and manage optional webhook subscriptions.

Base URL: https://web.signcustomiser.com/api . Download the OpenAPI YAML , create an API token , and use the endpoint index below as your starting point.

This reference covers the API contract. To embed the customiser, configure your integration, and get your integration ID, use the Custom API Integration guide alongside these endpoint pages.

Custom integration flow

A working custom integration has two essential backend steps. Handle the product creation callback first, then submit the completed order once checkout finishes in your own platform.

  1. Product created : When a customer finishes a design, Sign Customiser POSTs the product payload to the create-product URL configured on your custom integration. Verify the signature, create the product in your own platform, and return the external_id you want Sign Customiser to store.
  2. Create an order : When checkout completes in your own platform, submit the finished order to Sign Customiser. Each products[].external_id value must match a product ID you previously returned from the product creation callback.
  3. Create a new webhook : If you also want outbound notifications in your own systems, register webhook subscriptions for order, product, or form events.

Endpoints

The API reference is grouped by use case. Deprecated routes stay visible for existing merchants, but they are marked directly on the endpoint entry.

Custom integrations

Backend contract for custom integrations: handle the signed product creation callback, return your own product ID, then submit completed orders into Sign Customiser.

Webhook events

Signed delivery payloads sent from Sign Customiser to your own application, including the product creation callback used by custom integrations.

  • Product created : Use this as the product creation callback for custom integrations. When a customer finishes a design, Sign Customiser POSTs this payload to the create-product URL configured on your custom integration. Verify the signature, create the product in your own platform, then return a 200 JSON response containing the external_id you will later send in POST /api/v2/orders .
  • Order created : Delivered when Sign Customiser records a completed order for your organisation.
  • Form submitted : Delivered when a customer submits a Sign Customiser form workflow.

Webhooks

Manage webhook subscriptions and inspect the event topics Sign Customiser can deliver to your own systems.

Authentication

Request endpoints in this reference use bearer token authentication. Generate your token in the Universal app and keep your JSON headers explicit in every outbound request.

API request headers 
Authorization: Bearer YOUR_API_TOKEN
Accept: application/json
Content-Type: application/json

Webhook deliveries

Webhook event pages in this reference show the signed POST deliveries that Sign Customiser sends to your own endpoint. Validate the timestamp and signature before you process the payload, and use the webhook setup guide if you need the full verification flow.

Webhook delivery headers 
x-webhook-timestamp: 1704067200
x-webhook-signature: YOUR_GENERATED_SIGNATURE

Published webhook events in this reference: Product created , Order created and Form submitted .