Kumiki A/B
Agent-native A/B testing. Free, self-hosted, MCP-first.
Run experiments from Claude Code. Apply winning variants to 100% of traffic — no paywall, no SaaS bill.
Quickstart
# 1. Deploy your backend
npm create kumiki@latest ab
# Follow printed steps: wrangler d1 create → paste id → migrations apply → wrangler deploy
# 2. Add the snippet to your site's <head>
# <script src="https://<your-worker>.workers.dev/s.js?site=SITE_ID"></script>
# 3. Mark conversions
# window.KUMIKI.track('purchase', { value: 4980 })→ Full install guide — CLI, Deploy-to-Cloudflare button, agent-native, GTM (3-tier), and marking conversions (Step 3).
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Why
Every A/B tool charges you for the one thing that actually matters: applying the winner.
VWO, Optimizely, and Optimize Next all gate "winning variant → 100% rollout" behind paid plans (¥100k+/mo). Kumiki A/B makes it free, self-hosted, and fully operable by an AI agent via MCP.
Hero features
- Win-pattern application — free. Roll the winning variant to 100% of traffic with a single MCP call.
- MCP-first. Every operation — create test, update traffic split, read results, apply winner — is callable from Claude Code. No dashboard required.
- Self-hosted on Cloudflare. Experiment data is self-collected into your own D1 — never pulled from a third party. You don't even need GA4 configured to run kumiki; if you have it, we emit events out to it. Zero vendor lock-in.
Stack
| Layer | Tech | |---|---| | Snippet | Lightweight JS (<head>) — anti-flicker, sticky bucketing, fail-open, self-collected exposure/conversion events (emitted to GA4 too) | | API | Cloudflare Workers + Hono + D1 | | MCP server | Full REST coverage for Claude Code | | Dashboard | Next.js 15 + visual editor (iframe) | | Stats | Bayesian (beta-binomial) — peeking-resistant | | Events | Self-collected store in your own D1 — user-based, windowed; emitted out to GA4/webhook, never pulled |
Status
Early development. Dogfooded on real e-commerce traffic.
License
MIT
