Evidence Contract

Procedure

Phase 1: define claim types

1. internal-only
2. runtime-visible
3. boundary-sensitive
4. security-sensitive

Phase 2: map required proof

1. define minimum evidence classes per claim type
2. define required failure-mode coverage where needed

Phase 3: define downgrade policy

1. define confidence downgrade when evidence is missing
2. define block thresholds for high-risk claims

Proof requirements

• every claim type has explicit minimum proof class
• missing evidence triggers deterministic downgrade behavior
• high-risk claims cannot pass on synthetic-only evidence

Common failure patterns

1. one proof standard for all claim types
2. no downgrade rules for missing evidence
3. evidence lists without class semantics

Adaptation notes

• allow local evidence sources, keep contract semantics stable
• preserve class names across repos for report comparability

Handoff format

EvidenceContract Report

Claim types:
Evidence classes:
Requirement matrix:
Downgrade policy:
Block thresholds:
Adoption recommendations: