For developers

The standard is the source.

SIGNET is a public repository of JSON Schemas, codelists, worked examples and a conformance suite. This site is generated from it. Build against it directly.

Start here

terminal

git clone https://github.com/concerthq/signet-standard.git
cd signet-standard && npm install
npm run validate      # validate the examples against the schemas
npm run transform     # convert the invoice to Peppol BIS Billing 3.0
npm run verify-ubl    # reconcile the result against the source invoice
npm run conformance   # run the conformance suite against the reference adapter

What you can rely on

Licence. The schemas, codelists and examples are in the public domain under CC0 1.0. The conformance harness is Apache-2.0.
Stable identifiers. Schemas resolve under https://concert.foundation/signet/v0.1/ and can be referenced directly.
One source of truth. Where the prose and a schema disagree, the schema governs.

Three things to build

Accept or emit SIGNET documents. Validate what you read and write against the published schemas.
Test your own implementation. Write a conformance adapter and run the public suite against it. You see the same report Concert would.
Propose a change. Every change arrives by pull request. Normative changes carry a comment period of at least fourteen days.