Verifier M2M Integration Guide

This guide describes how backend services and machine-operated components can integrate with the Verifier acting as an Authorization Server (AS) in machine-to-machine (M2M) scenarios. It specifies the end-to-end process required to obtain and use OAuth 2.1 access tokens based on the client_credentials grant, where client authentication relies on a Verifiable Presentation (VP) embedding a LEARCredentialMachine. The document explains the prerequisites, client onboarding and registration, secure handling of keys and credentials, construction of the VP and client assertion JWT, token acquisition via the Verifier Token Endpoint, and subsequent use of issued access tokens to call protected APIs. It also highlights security requirements, error handling, observability practices, and common pitfalls to ensure robust and interoperable integration across the ecosystem.