Document Signing V3

Last Updated: 2 June 2025

V3 continues our mission to enhance the convenience and security of digital signing in Singapore. It significantly reduces technical complexity, ensuring faster and safer implementation, and provides greater access to digital signing to businesses and citizens across various aspects of their lives.

Change log

Date
Changes

2 June 2025

Initial version

High-level integration flow

Relying Parties (RPs) will send us the document, and then redirect the user to our Sign portal to perform the signing. Sign will then notify the RP of a successful signing via their webhook, from which RPs can retrieve the signed document.

Sign V3 High-level integration flow

RPs are expected to implement the following steps referenced from the diagram above:

Step
Component
Summary
Specifications

1

Backend

Send raw document to Sign with Singpass and get signing_url

2

Frontend

Redirect user to Sign with Singpass

Redirect user to the Sign Portal via the signing_url retuned in step 1. RP should follow UX Guidelines to render the "Sign with Singpass" button.

3.1

Frontend

Accept redirect from Sign with Singpass

3.2

Backend

Accept success signing webhook

4

Backend

Get signing result

5

Backend

Download signed document

N/A. Just fetch the signed document from signed_doc_url

0

Backend

JWKS specifications

Production and staging URLs

Staging Base URL: https://staging.sign.singpass.gov.sg/api/v3

Production Base URL: https://app.sign.singpass.gov.sg/api/v3

Developer tools

Demo App

Sign V3 Demo App is a reference implementation that demonstrates how RPs can integrate with V3. It helps partners explore the API and conduct early-stage integration testing.

Mockpass

Mockpass is an open-source mock server that stubs various Singpass APIs, including the Sign v3 signing flow. It is designed for local development, CI and low environment testing, enabling fast, repeatable, and secure integration without relying on staging infrastructure.

Sign Location helper

Sign Location Helper is a fully client-side browser-based tool for visually determining signature coordinates within a PDF document. It allows users to upload a PDF, place and drag signature boxes, and copy normalised (x, y, page) values for use in Sign v3. Ideal for RPs experimenting signature placement.

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