msr-validator

The reference validator library for MSR JSON manifests, in Python.

Status: implementation in progress. Nothing is published on PyPI yet.

Role in the MSR JSON project

msrjson/specification        source of truth: schemas, examples, RFCs
        ▲
        │  bundles the schema of a pinned release tag
msrjson/msr-validator        this repository: the library
        ▲
        │  depends on
msrjson/msr-cli              the `msr` command-line tool

Dependencies point one way only. This library never depends on the CLI, and the specification depends on nothing.

Its first consumers are software registries — such as mysoftrank.com — that must validate every manifest they index. A registry that imports this package instead of keeping its own copy of the schema cannot drift from the standard.

Rules this implementation follows

• No committed copy of the schema. The package ships the canonical schema so it can validate offline, but that file is generated at build time from a pinned release tag of msrjson/specification, is gitignored, and CI fails if it is not byte-identical to that tag.
• The supported protocol version is explicit. Each release states which MSR JSON versions it validates.
• Python, published on PyPI as msr-validator.

API

from msr_validator import validate

result = validate(open(".well-known/msr.json").read())
if not result.valid:
    for error in result.errors:
        print(error.path, error.message)

The package validates offline against the byte-pinned schema from specification tag v2.0.0. Build time downloads that schema, verifies its SHA-256 digest and includes it in the wheel; source control never includes a second schema copy.

Author

MSR JSON was created by Antonio Santos. See the specification's AUTHORS.

License

MIT. The specification and schemas it validates against are CC-BY-4.0, in the specification repository.

Experimental MSR JSON 2.1 validation

Until 2.1 is ratified and pinned, pass the local draft schema explicitly. The default remains the bundled MSR JSON 2.0 schema.

result = validate(manifest, schema_path="path/to/msr-2.1-draft.json")