# Schema Catalogue

# Schema Catalogue

This catalogue explains the schemas published by the Hub and what they are for.

## Metadata schema

The metadata schema defines what a publisher declares about itself. This includes open-use stance, contact fields, and optional certification declarations.

## Innovation ledger entry schema

The ledger entry schema defines the structure of a provenance record. The goal is to make “one idea = one Markdown file” mechanically parsable.

## Certificate schema

The certificate schema defines what a certificate artefact must contain if certification is claimed. This prevents empty certification claims.

## Audit event schema

The audit event schema defines the shape of a tamper-evident event record used for restricted actions such as NDA-gated downloads.

## Where to find them

See:

`/.well-known/aiep/schemas/`

and the downloadable schema bundle under `/downloads/schemas/`.