Onyxa

Onyxa is a browser-based composer for ONIX, the international metadata standard publishers use to describe books to retailers, libraries, and distributors. ONIX files are large, deeply nested XML, and most tooling around them is either enterprise software or a hand-rolled spreadsheet export. Onyxa is a place to actually read and edit one.

It opens existing files in ONIX 2.1, 3.0 or 3.1, in reference tags () or short tags (), single records or full feeds, detecting the version from the file. It converts between versions in both directions and tells you which fields cannot survive the trip before you commit to it. It validates as you type, against the complete Issue 74 code lists.

The part I'd point at: every field in the standard is reachable, and that's a measurement, not a claim. Rather than hand-writing several hundred form controls, the app generates an element registry from EDItEUR's own schemas, then renders forms from it. A check in the build asserts that all 1,454 elements across the three releases are both editable in the UI and survive a parse → serialize → parse round trip in both tag styles. It fails the build otherwise. Current gaps: zero.

There is no server. Schemas, code lists, parsing, validation, conversion and export all run client-side; drafts autosave to local storage. Nothing you open is uploaded anywhere — which for unreleased catalogue data is the point.