Format contracts

Document versionDateSummary
v12026-08-07Collect the format contracts into one directory

This directory holds the normative engineering contracts for the artefacts the project reads and writes. A contract states what an artefact is, field by field, so that a second reader on another platform can be written from the document rather than from the code that already exists. The decision behind a format, and the alternatives it rejected, belong to its ADR instead.

DocumentArtefactVersion
asset manifest v1the canonical manifest.petasset text grammar and the pet presentation schemav0.2.0
save format v1the 84-byte saved world payloadv0.4.0
asset pack v1the embedded asset pack the converter writes and the device readsv0.5.0

File names carry the format version rather than the product version, because a format outlives the release that introduced it. A new version of a format is a new document beside the old one, and the old one stays as it is, because something written by an earlier release may still have to be read.

Each contract states its own compatibility promise, and the three differ on purpose. The save payload is user data that must outlive the process that wrote it, the pack is a build output that never leaves the firmware image that reads it, and the manifest is a project-owned authoring source rather than a modding interface.