These constraints cannot be changed without breaking VATFIX.
Given the same input and authority state, VATFIX produces the same output.
No randomness. No "best effort." No approximation.
Every evaluation produces evidence.
Evidence is the product, not the validation result.
When VATFIX consults an external authority, it records:
- Which authority
- When
- What response (or failure)
No silent failures. No hidden sources.
All failures are classified.
Unclassified failures are bugs.
When an authority is unavailable, VATFIX does not:
- Return cached data without disclosure
- Guess the result
- Suppress the failure
Unavailability is reported as UNAVAILABLE, not as success or failure.
VATFIX defines rules.
Implementations execute rules.
Implementations cannot modify rules.
The VATFIX registry is append-only.
Removal requires explicit governance action with audit trail.