Compatibility and deprecation

Surface	Current	Compatibility rule
Project record	10	Exact current schema only; older records are rejected.
Spatial geometry	1	Canonical metres with millimetre serialization precision.
Venue Template catalog	1	Exact current schema only; older template documents are rejected.
Validation engine	2.7.0	Comparable only when engine and immutable input fingerprints match.
Simulation engine	1.2.1	Comparison requires matching engine and Scenario definition fingerprints.
Activity Ledger	1	Hash-chain verification is required on load, replay, and export.
Tool contracts	1.6.0	Shared by WebMCP, standalone MCP, schemas, examples, and skills.
MCP server	0.7.0	Preferred protocol 2026-07-28; minimum 2025-03-26.
TypeScript SDK	0.1.0	ESM-only on Node.js 22+; SDK SemVer remains independent of tool, adapter, and Project schema versions.
Agent skills	1.4.0	Targets tool contract 1.6.0.
Interchange Package	1 + Project schema 10	Create-only import with exact schema, checksum, geometry, Locks, ledger, and replay preflight.

Change	Policy
Breaking contract or schema	Publish a new major contract or schema version with an explicit migration path; retain the prior published artifact.
Additive field or operation	Publish a minor tool-contract release and update generated schemas, examples, skills, and changelog together.
Clarification or remediation text	Publish a patch release when runtime behavior is unchanged.
Deprecated tool or field	Mark it in machine-readable metadata and the changelog for at least one full minor release before removal.
Stable identifier	Preserve it across revisions and migrations; create a new ID only when identity or transformed lineage changes.

DOCS

Compatibility matrix