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	Initiate Sign Request
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	Redirect From Sign with Singpass
3.2	Backend	Accept success signing webhook	Accept Success Signing Webhook
4	Backend	Get signing result	Get Signing Result
5	Backend	Download signed document	N/A. Just fetch the signed document from signed_doc_url
0	Backend	JWKS specifications	JWKS Specification

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

These tools are open-source community projects and are not officially supported or maintained by the Sign team. We welcome contributions to improve them. Their inclusion here does not imply endorsement or preference by the Sign team.

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. Ideal for RPs building or validating Sign v3 features.

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.