Open-source · Apache 2.0 · v1.7.3

Pre-deployment security audits for fintech that actually catch the bugs that ship money to attackers.

294 hand-curated checks across 33 reputable frameworks — PCI-DSS, MiCA, DORA, NYDFS, OWASP, NIST, CCSS, FATF — with AI-augmented findings and one-click patch suggestions. Runs in seconds. Your code never leaves your machine.

brew install preston-check/preston-check/preston-check
Sample score badge: A-, 87 of 100

Three commitments

Built around the rules fintech actually has to follow.

Most security scanners are general-purpose. Preston-Check is fintech-narrow — its catalog is curated, not crawled, and every check cites the framework control or real-world incident it stems from.

Open scanner, paid SaaS layer.

Every check, every framework filter, every report format runs free. The commercial product wraps the output, not the engine.

AI-augmented, never AI-only.

The grep catalog runs first. Then an LLM filters false positives, explains in plain English, and (with --ai-fix) writes the patch.

Your code never leaves your machine.

Telemetry is opt-in. AI calls are opt-in. --airgap kills every outbound request. The privacy promise is auditable in 30 lines of bash.

In your terminal

What a scan actually looks like.

Colored pass/fail/warn output, a final score, and a markdown report your auditor can sign off on. Same engine in the CLI, GitHub Action, Docker image, and Homebrew formula.

~/payments-api · preston-check --high-and-up
============================================================================
  Preston-Check — Pre-Deployment Security Audit
  2026-05-04 14:22:08
============================================================================

  App:     payments-api
  Lang:    typescript (primary) | TypeScript(118) Solidity(7)
  Mode:    FULL (all enterprise security checks)
  License: free tier (no license installed)
  OSS: detected (Apache-2.0) — Pro features granted free for this repo
  Telemetry: opt-in (anonymous score reported)

----------------------------------------------------------------------------

P-01: Hardcoded Secrets
[PASS] P-01 Hardcoded secrets             No hardcoded secrets in source
P-05: Idempotency Guards
[PASS] P-05 Webhook idempotency           Idempotency middleware present
P-12: Balance Validation
[FAIL] P-12 Balance validation            No balance validation before withdrawals
P-103: Double-Spend Prevention
[FAIL] P-103 Money idempotency           Transfer endpoint missing dedup key
P-308: Bridge Replay Protection
[WARN] P-308 Bridge replay                Cross-chain handler accepts unsigned msgs
P-712: Refund / Claim Authorization Missing
[PASS] P-712 Refund authorization         msg.sender enforced

  PASS: 261  FAIL: 5  WARN: 21  SKIP: 7
  Score: 88%   Grade: A−

What ships in the box

Nine surfaces, one engine.

Catalog of 294 checks

284 main + 10 deep smart-contract. Each check cites its framework control and the real-world incident it traces back to.

AI auto-fix

Pass --ai-fix, get a unified diff per finding. Applies cleanly with git apply. Cached per finding so reruns are free.

Threat-intel pipeline

Weekly NIST NVD ingest drafts new checks into community/proposed/. The catalog grows without you babysitting it.

Score and grade

Single A–F letter grade plus 0–100 numeric score. Calibrated against opt-in telemetry from peer fintechs.

Smart-contract module

10 deep checks (P-700 to P-719) traced to real production audit findings — HTLC, cross-chain replay, governance attacks, oracle manipulation.

Compliance evidence bundles

Group findings by framework control (PCI-DSS 6.5.1, SOC 2 CC6.1, MiCA Art 27). Hand the PDF to your auditor.

CI integrations

GitHub Action, GitLab CI, CircleCI, pre-commit hook, Docker image, Homebrew, raw shell. Same exit codes, same report.

Severity / framework filters

--critical-only, --high-and-up, --framework MiCA. Run the slice that matches the gate you're protecting.

Customer + admin portals

SaaS layer for multi-repo aggregation, branded PDFs, billing, license issuance, threat-intel triage. Free scanner stays free.

33 reputable frameworks

Curated, not crawled.

Every check carries the framework citation in its metadata. Filter by --framework "PCI-DSS" to produce a PCI-only audit; same for any other.

PCI-DSS v4.0 PCI 3DS EMVCo 3DS 2.x MiCA (2024) TFR (2023) PSD2 + PSD2-RTS DORA (2025) NYDFS Part 500 FinCEN 31 CFR OFAC SDN MAS TRM APRA CPS 234 RBI CSF FATF Rec. 2023 Travel Rule Rec. 16 SOC 2 (TSC 2017) ISO 27001:2022 ISO 22301:2019 OWASP API Top 10 2023 OWASP Top 10 2021 OWASP Mobile MAS 2024 OWASP LLM 2025 OWASP SC Top 10 2025 NIST CSF 2.0 NIST SSDF 1.1 FIPS 203 / 204 / 205 CCSS v9.0 CIS Controls v8

Pricing

Free forever. Pay when the SaaS pays you back.

The scanner — every check, every framework filter, every report format — is Apache 2.0. The portal is what you pay for: branded PDFs, multi-repo dashboards, compliance evidence, license management.

Free

$0 · no signup, no email
  • Full 294-check catalog
  • All framework filters
  • Markdown + local PDF reports
  • GitHub Action, Docker, Homebrew
  • AI augmentation (bring your own key)
  • Free Pro features for OSS repos
Install →

Enterprise

$29,999+ / yr · sales-led
  • SSO (SAML + OIDC)
  • White-label dashboards
  • Custom check authoring service
  • Signed audit packages
  • Dedicated success contact + SLA
  • On-premise deployment option
Talk to sales →

Why "Preston-Check"

Named after the attacker.

Preston X created multiple fake accounts on a production fintech platform. Bypassed 2FA. Ran 21,201 automated session-polling calls. Probed for race conditions and information leakage. Every check in the catalog traces back to a lesson from that attack — or one like it.

The pattern library was validated against a base of over 1.3 million logged session and request traces captured during the incident — every authentication flow, withdrawal attempt, configuration probe, session lifecycle, and rate-limit interaction. Each check graduates to the catalog only after surviving that corpus, which is why Preston-Check's false-positive rate is materially lower than tools built only against synthetic fixtures.

1.3M+
Logged traces analyzed
21,201
Polling calls observed
294
Checks in catalog
33
Frameworks covered
The catalog is curated, not crawled. Every check is grounded in a real incident, a real framework control, or a real production audit finding — which is why Preston-Check produces fewer false positives than tools five times its size.

Run a full security audit in your project today.

One command. No signup. No telemetry by default. Apache 2.0 forever.