Everything you need
to evaluate PAYKX

Bearer token required on all authenticated endpoints. Keys are SHA-256 hashed before storage — plaintext never persisted. Returned once at issuance only. Admin operations require a separate high-entropy secret.

TLS 1.2+ on all API traffic. HTTP connections rejected in production. Auto-renewed platform-managed certificates.

Database encrypted with AES-256. No payment instruments (IBANs, card numbers) stored at any layer.

HMAC-SHA256 on every webhook delivery. Signature verified before processing. Replay-safe via event_id deduplication. See docs →

Admin routes (/api/admin/*) require a separate X-Admin-Key. No API key can ever perform admin operations. Fails closed on missing or invalid credentials.

Store keys in a secrets manager (AWS SM, HashiCorp Vault, GCP SM). One key per environment. Rotate immediately if compromised — revocation within 60 seconds. Full guide →

Corridor codes and amounts are not personal data under GDPR. PAYKX does not act as a data processor for personal information. No data subject rights requests are required for PAYKX decision records. Full privacy policy at /privacy.

Sandbox infrastructure runs in the EU. Production deployments can be configured for specific data residency requirements. Contact access@paykx.co.uk to discuss.

Assessment Engine designed to support FCA and EBA record-keeping requirements for payment service providers. Structured for MiFID II / PSD2 audit trail obligations.

Request and response schema aligns with ISO 20022 payment message conventions. Decision IDs are structured for integration with SWIFT GPI tracking references.

Every manual override records the operator identity, role, reason code, and justification. Linked permanently to the original PAYKX decision — tamper-evident by design. See audit docs →

PAYKX provides Execution Assurance only. It does not move, hold, or settle funds. This means PAYKX does not require an e-money licence, payment institution registration, or PCI-DSS scope.

Every verification decision is a write-once immutable record. Records cannot be modified or deleted via any API call. Override records link to decisions without altering them.

Decisions and overrides: 7 years. Webhook delivery logs: 30 days. Exports: generated on demand. Configurable on request for jurisdictions with different requirements.

GET /api/v1/audit/export/:id returns a structured PAYKX_COMPLIANCE_AUDIT report with full signal breakdown, decision, and override actor chain. Suitable for internal audit teams and external regulators.

GET /api/v1/audit/:id returns the complete record for any past decision: score, confidence, volatility, all 7 signal values, and any associated override. Available immediately after each verification call.

PAYKX-v1.3.0 — production_ready. Previous: PAYKX-v1.2.0. Change: updated FX volatility weighting + improved historical failure rate signal accuracy. See live metadata →

7 signals scored in parallel: fraud/AML flags (20%), network health (18%), FX volatility (17%), historical failure rate (15%), balance sufficiency (13%), operation validity (12%), COP override (5%). Deterministic — same input always produces the same output.

GO ≥ 0.80  ·  WAIT/DEGRADED 0.48–0.79  ·  NO-GO < 0.48. Plus a policy cap that escalates large transfers regardless of base score.

Every model version is tagged and immutable. The /api/v1/model/version endpoint returns model_status, previous_version, and change_summary — suitable for enterprise change management workflows.

GET /api/v1/decision/:id/explanation returns per-signal confidence impact, the worst signals first, and a recommended action. No black-box decisions.

ISO 20022 aligned. All data types and field names follow payment industry conventions. No proprietary schema lock-in.

All data in the current deployment is simulated. The Assessment Engine runs identically to production — but against synthetic validation scenarios. No real funds, no real counterparties, no real rails touched.

You can integrate fully against the sandbox API, run load tests, test error paths, and build your compliance workflow — all without any risk of affecting real payments or triggering regulatory obligations.

Shadow mode responses are structurally identical to production responses. All fields, status codes, headers, and error shapes are the same. No code changes are required when upgrading to a production key.

Every API response includes X-PAYKX-Environment: sandbox and X-PAYKX-Version: v1 headers, plus an "environment": "SANDBOX" field in the JSON body. Impossible to confuse with a live call. Full shadow mode docs →

The PAYKX Phase 2 Evidence dashboard compares model predictions against real-world corridor outcomes — tracking where GO decisions matched successful transfers, and where NO-GO decisions avoided corridor failures. Updated continuously as new verification data accumulates.