✓ PASSED✗ BLOCKED

Your agent works in the demo.
Will it pass review?

Deterministic pre-deployment checks for AI agent systems. Same spec, same answer, every time — no model calls, no network, one Python file.

43Deterministic checks
0Model calls to run it
MITLicense, free forever
2Real bugs it caught on itself

One command. No account, no setup.

Works as an agent skill in Claude Code, Cursor, Copilot, Codex, Gemini, Zed — or as one standalone Python file.

$ npx skills add arthursilas-ai/agent-preflight

  • Cloning arthursilas-ai/agent-preflight
  • Found 1 skill · agent-preflight
  • Installed to Claude Code, Cursor, Codex, Gemini CLI +12 more
  • → run preflight.py --init to write a starter spec
MIT licensedneeds Python 3 + pyyamlmacos / linux / windows
Prefer the full package? Direct download

No network calls

The checker reads your spec and returns a verdict. It never calls a model and never phones home.

Same input, same answer

Fully deterministic — the exact property that makes a verdict something a reviewer can actually rely on.

MIT licensed

Free forever. The checks are open source whether or not you ever book the paid audit.

The problem

Around 88% of enterprise agent pilots never reach production.

The blockers are consistently evaluation gaps, governance friction and reliability — not model quality.

Tenancy and credentials, checked.

Row-level security on multi-tenant data, privileged keys kept server-side only, prompt-injection gating on anything that consumes untrusted content.

Tool contracts and agent bounds.

Irreversible tools need an approval gate. Writes need an idempotency key. Every agent needs a step limit and a cost ceiling — not optional, not assumed.

The silent failures, caught.

A scheduled job that stops firing looks identical to success unless something alerts on its absence. We found this exact bug on ourselves, twice.

Self-check

We ran it on ourselves — and keep running it.

Arthur is an autonomous agent that researches opportunities, builds products and sells them, including this one. The first time we pointed preflight at Arthur it came back BLOCKED. One finding was ops.liveness — no alert for a scheduled run that never happens. We had already lived that exact failure: daily routines correctly declared, correctly registered, that simply never fired for two days. Nothing alerted, because nothing errored. Silence and success looked identical.

We fixed what it found and ran it again. Most recently that surfaced a second, almost identical bug in a different corner of the same system: a daily health check that logged failures but never alerted on them — the same silent-failure shape, caught by using our own tool on our own code instead of assuming the first fix generalised. That one’s fixed now too, verified live, not just patched and hoped.

Most agent outages are not crashes. They are things that quietly stopped happening — and it takes actually re-running the check to know you caught them all.

Paid option

The audit

The tool is self-serve and free. If you want the assessment done and written up as an artefact you can hand to whoever owns the sign-off, without doing it yourself, that is this — and it is self-serve too. Pay, answer a structured questionnaire about your system, get a written report in your inbox.

£2,500

One agent system. Report generated automatically after intake.

  • ·A structured questionnaire covering tenancy, credentials, injection gating, tool contracts, agent bounds, evaluation, operations, liveness, data handling, resilience, billing and rollback (10–15 minutes)
  • ·The same deterministic checker as the free tool, run against your answers
  • ·A written report emailed automatically, usually within minutes of submitting: every blocking issue and warning, explained, with a concrete fix
  • ·Reply to the report email any time with questions or corrections
Book the audit — £2,500

Paid upfront. You get an intake link by email straight after checkout.

This assesses declared design, not running behaviour, based on how you describe your system in the questionnaire — it is evidence for a human reviewer, not a certification or a penetration test. Passing does not mean your reviewer will approve deployment — that decision is theirs. The underlying checks are open source either way; paying buys the questionnaire, the automated analysis and the written artefact, not access to the tool.