SafeGate v5.2.1 / Freeze Index / Public Review

API Contract Freeze Index

This page freezes the current Receipt Verify API mock and API contract direction before SafeGate moves into merchant verification console design.

SafeGate principle:
Payment is the trigger. Trust is the product.

Boundary: This freeze index does not claim a production public API, does not expose API keys, does not expose backend secrets, and does not claim Pi Mainnet settlement proof. Current public evidence remains a controlled Pi Testnet post-payment trust flow.

1. Frozen API Review Pages

v5.1 Receipt Verify API Mock

Public mock architecture for receipt verification. Shows how a finalized payment can map to receipt proof, access unlock, and merchant-side record.

Open v5.1 →

v5.2 API Contract + Error Boundary

Defines the response envelope, success and error responses, fail-secure behavior, no secret exposure, no ID enumeration, and production readiness checklist.

Open v5.2 →

Merchant/API Direction

Shows the broader merchant/API path without claiming a live production public API.

Open Merchant/API Direction →

Security Hardening Check

Public security boundary and hardening checklist for reviewer context.

Open Security Check →

2. Frozen Contract Scope

{
  "frozenStage": "v5.2.1",
  "scope": "Receipt Verify API Mock + API Contract + Error Boundary",
  "productionPublicApiClaim": false,
  "publicApiKeySystemClaim": false,
  "backendSecretExposure": false,
  "piMainnetSettlementProofClaim": false,
  "currentEvidence": "Pi Testnet controlled post-payment trust flow",
  "nextStage": "v5.3 Merchant Verification Console Mock"
}

3. Frozen Response Coverage

200 RECEIPT_VERIFIED success response.
400 INVALID_RECEIPT_ID malformed input response.
404 RECEIPT_NOT_FOUND generic not-found response.
401 UNAUTHORIZED_MERCHANT future production boundary.
429 RATE_LIMITED future anti-enumeration boundary.
503 VERIFICATION_AMBIGUOUS fail-secure no-unlock boundary.

4. Frozen Security Rules

No backend secret, service role, wallet passphrase, access token, or API key exposure.
No stack trace, database name, table name, internal file path, or infrastructure leakage.
No ID enumeration through receipt IDs, merchant IDs, payment IDs, or adjacent records.
Invalid, missing, ambiguous, timed-out, or conflicting states must fail secure.
Access must not unlock from UNKNOWN, FAILED, PENDING, ambiguous, or duplicate replay states.

5. Why This Freeze Matters

SafeGate is moving from public proof pages into merchant-facing verification design. Freezing v5.1 and v5.2 creates a stable review checkpoint before adding UI/console layers.

Reviewer takeaway: SafeGate is not only documenting a demo. It is defining the API behavior, error boundaries, fail-secure logic, and production constraints required for a payment-triggered trust layer.