Maybe I missed it but is this conversion/standard public already? I am certainly interested.
The CLI tool to do the conversion for Altium Schematics to JSON and/or svg is packaged in our diff application, which we’re providing totally free: https://www.allspice.io/download
There’s some info on how to use the CLI in the blog post I linked in the initial post.
If you’d like a direct download for just the CLI tool, send me a DM and I’ll get something to you.
We still don’t have 100% coverage for all of the schematic data (for instance, embedded images are not included), but all components, nets, and traces are included in the JSON. We should have initial PcbDoc support by early next week. Over the next several weeks we’ll work on expanding coverage and documenting the JSON format for review from the community.