`xantham` - the command line over the generator. Every command is a shell over a library function the test harness calls as well: `generate` is `Pipeline.run`, `schema` is `Schema.json`.

The JSON Schema for `xantham.json` (decision O4), emitted from `GeneratorConfig`, `GroupDisposition` and `MappedName` by reflection. The property set, their JSON types and the disposition vocabulary are read from the F# declarations; the key spellings and the descriptions are read from the tables here, which carry an entry for every member.