Core invariants (spec)

These invariants must hold across refactors. If an invariant must change, treat it as a breaking change and bump the relevant schema/version.

Documentation invariant

• Every docs/**/*.md file MUST be tracked in docs/doc_checksums.json.
• docs/index.md MUST list every tracked documentation file.

(This is enforced by tests.)

Canonical pipeline invariant

• The canonical phase order and allowed transitions MUST remain stable at runtime.
• Any intentional change MUST be accompanied by a clear versioning decision and updated spec text.

Failure taxonomy invariant

• Every FailureClass MUST have a profile.
• Failure artifacts MUST validate against taxonomy profiles.

Trace identity invariant

• Traces MUST record schema version, runtime version, and model metadata.
• Replayability MUST be classified in the trace header.

See also:

• docs/spec/invariants/determinism.md
• docs/spec/failure_model.md