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AB Test Research Designer

Release License: MIT Python Node Tests Coverage Lighthouse Docs

Local-first experiment planning tool for A/B and multi-variant tests. Plan sample size and duration from the wizard, review deterministic statistical guidance (SRM, Bayesian, group-sequential, CUPED, guardrails), compare saved experiments side by side, and export decision-ready reports in seven languages (English, Russian, German, Spanish, French, Simplified Chinese, Arabic with RTL) — all against a local SQLite workspace with no cloud required.

Built with FastAPI + React 19 + TypeScript + Vite + SQLite, verified end-to-end via scripts/verify_all.cmd --with-e2e (350+ backend tests, 200+ frontend tests, Playwright E2E, Lighthouse CI, axe accessibility checks). Backend coverage gated at 89%+ in CI.

It combines:

  • deterministic sample size and duration calculation
  • heuristic warnings and feasibility checks
  • deterministic experiment design output
  • optional local LLM recommendations
  • SQLite-backed project storage with history and export metadata
  • lightweight runtime diagnostics plus request-id / process-time headers
  • baseline security headers, API rate limiting, auth-failure throttling, and request-body size guards
  • SQLite schema versioning plus configurable WAL/busy-timeout runtime settings
  • optional API token protection for runtime and project APIs
  • workspace backup and restore for saved projects plus history, integrity counts, checksums, and optional HMAC signatures
  • preflight workspace validation before import, plus runtime SQLite write-probe diagnostics

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