# Prufa

> Prufa is an AI QA engineer for web products — robust QA software built for the agentic era. An LLM-backed agent navigates an app like a real user (signup, login, checkout); plain code verifies every result. Verified findings are machine-checked with evidence; LLM judgments are clearly labeled advisory and never graded as facts. Humans get a dashboard, shareable reports, and Slack alerts; agents get a CLI, HTTP API, MCP server, and an agent skill — the same product through both surfaces.

Things an agent should know before calling Prufa:

- Free 60-second audit, no signup: `POST /api/v1/audits` with `{"url": "https://..."}` returns a report URL and an SSE progress stream. Public pages only; reports are unlisted and noindex by default.
- Every mutating endpoint accepts an `Idempotency-Key` header — retries after network blips are safe.
- The API is versioned (`/api/v1/`) and OpenAPI-published; response shapes do not change within a version.
- BeaconEvent v1 and flow-spec v1 are public, versioned specs — you are encouraged to emit and consume them.
- Monitoring never pollutes customer analytics, and full-auto discovery runs only on customer-authorized domains.
- Paid monitoring is per workspace, prepaid, hard-capped by default (monitors pause at quota; overage is opt-in): Starter $29/mo (500 runs, 3 sites), Pro $99/mo (5,000 runs, 10 sites, MCP server + agent skill access), Team $179/mo (50,000 runs, unlimited sites, 5 seats). 7-day card-first trials; agents get a 7-day no-card setup tier (register sites, run audits, draft flows — persistent monitors need a paid plan). One LLM call = one run — and confirmed flows whose pinned selectors still work replay as plain code: zero LLM calls, zero metered runs. The model re-engages (and meters) only when the UI changes and a selector needs re-resolving.

## Agent surface

- [Agent skill (SKILL.md)](https://prufa.dev/skill/SKILL.md): the landing page for agents — setup flow, tool calls, free-tier primitives, when to use Prufa
- [OpenAPI v1](https://prufa.dev/api/v1/openapi.json): the versioned, machine-readable API contract
- [API docs](https://prufa.dev/api/v1/docs): browsable reference for the same API

## Public specs

- [BeaconEvent v1](https://prufa.dev/docs/specs/beacon_event_v1.html): the versioned contract between browser capture and the deterministic check layer
- [flow-spec v1](https://prufa.dev/docs/specs/flow_spec_v1.html): the deterministic, reviewable format that plain-language test cases compile to
- [BeaconEvent JSON Schema](https://prufa.dev/docs/specs/beacon_event.schema.json): JSON Schema (Draft 2020-12) for BeaconEvent v1

## Blog

- [Blog index](https://prufa.dev/blog/): notes on AI QA — practical testing guides, engineering decisions behind Prufa, QA in agent workflows
- [QA for vibe-coded apps: what actually breaks](https://prufa.dev/blog/guides/qa-for-vibe-coded-apps/): nine failure modes, ranked by frequency, from a 49-launch audit (June 2026) — and the free audit that catches the top ones
- [How Prufa verifies a signup flow](https://prufa.dev/blog/engineering/how-prufa-verifies-a-signup-flow/): the trust architecture walked through one concrete run
- [We audited 49 Show HN launches](https://prufa.dev/blog/engineering/we-audited-49-show-hn-launches/): machine-verified findings from real launch-day sites — 78% had a critical bug
- [Website QA checklist before launch](https://prufa.dev/blog/guides/website-qa-checklist-before-launch/): pre-launch checks ordered by observed failure frequency
- [llms.txt in 2026](https://prufa.dev/blog/agents/llms-txt-who-actually-reads-it/): who actually reads llms.txt, with sources — and why we ship this file
- [RSS feed](https://prufa.dev/blog/rss.xml): machine-readable feed of new posts

## Comparisons

- [Compare index](https://prufa.dev/compare/): honest, dated comparisons of Prufa against managed QA services and AI testing platforms — every competitor claim carries a source link and check date
- [Prufa vs bug0](https://prufa.dev/compare/bug0/): AI QA agent or managed QA service — $29/mo self-serve vs $2,500/mo with a forward-deployed engineer (checked June 2026), including where bug0 wins

## Optional

- [Human landing page](https://prufa.dev/): overview for humans, with the free audit form
- [Pricing](https://prufa.dev/pricing/): plans, quotas, what counts as a run, how trials and hard caps work
- [Privacy](https://prufa.dev/privacy/): privacy policy
- [Terms](https://prufa.dev/terms/): terms of service