1. Introduction

This document defines the wire format, semantics, and HTTP retrieval mechanisms for the MSR JSON Protocol (Metadata for Software Registry) version 2.0.0.

2. Canonical Endpoint Discovery

An entity publishing an authoritative MSR manifest MUST serve the payload over TLS at the well-known URI:

https://<domain>/.well-known/msr.json

Clients crawling this URI MUST send an HTTP Accept header containing application/json, application/schema+json;q=0.9. Servers SHOULD respond with Content-Type: application/json; charset=utf-8 and appropriate Cache-Control directives.

3. Mandatory Payload Sections

Conforming manifests MUST define:

• $schema: Direct HTTPS URI to the canonical schema.
• protocol: Name, version, and license attributions.
• entity: Machine slug, primary domain, archetype, and localized descriptions.
• capabilities: Deployment modes, interfaces, and pricing.
• releases: Release version, release date, and binary artifacts.