What you get

Kumiko ships the parts of a business app you’d otherwise rebuild on every project. You declare what your app does; these come for free. Mount the ones you need — nothing here is a paid tier.

The core deal

Declare a feature, get the whole stack. One defineFeature() with an entity gives you a Postgres table, a typed API, validation, access rules, a search index, and a full admin UI — list, create, edit, filter — with no UI code from you.

Light Dark

Light Dark

• Schema is the source of truth — change a field, and the table, API, forms, and labels follow. → Concepts: Schemas
• Realtime is the default — changes stream to every open browser over SSE, and concurrent edits are safe (optimistic locking), not an add-on.
• Audit comes built in — every write is an event; you get a full history and time-travel for free. → Concepts: Events

Built-in features

These are pre-built features you mount in run-config.ts and configure — you don’t write them. Each links to its reference page.

Identity & access

• Users, tenants, sessions — multi-tenant accounts, tenant switching, and session lifecycle. → user, sessions
• Email + password auth — login, signup, password reset, email verification, and invites — all the screens included. → auth-email-password
• Feature toggles & plan tiers — gate features per tenant, enforce plan limits and usage caps. → feature-toggles, tier-engine

Communication & files

Notify and store

One call for email/push/in-app notifications; one API for file uploads with signed URLs — templates and delivery logs included.

• Notifications — one ctx.notify(...) call delivers over email, push, and in-app, with templates, preferences, and a delivery log. → delivery
• File storage — upload and serve files via S3 or local storage behind one API, with signed URLs. → files

Operations

Run and review

Background workers with run history, rate limits on handlers, and an audit trail for compliance — wired, not bolted on.

• Background jobs — register a worker, get scheduled and event-triggered runs with a persisted run history and operator retry. → jobs
• Rate limiting & audit — per-handler rate limits and an audit log for compliance reviews. → rate-limiting, audit
• Config & secrets — per-tenant config keys and tenant-scoped encrypted secrets. → config, secrets

Compliance & billing

GDPR and payments

Export, erasure, retention profiles, and Stripe/Mollie subscriptions behind one billing foundation — region-aware out of the box.

• GDPR tooling — data export (Art. 20), erasure (Art. 17), retention, and region profiles, wired end to end. → user-data-rights, compliance-profiles
• Subscriptions & billing — Stripe and Mollie behind one billing foundation. → subscription-stripe, subscription-mollie

See it running

Best way to learn

Clone a sample app, run bun dev, click through the generated UI — then read the feature file that produced it. Faster than reading bullet lists.

The capabilities above are easiest to grasp by running a real app:

• Marketing demo — an asset tracker and a helpdesk on one instance: the generated CRUD UI in full.
• ShowPony tutorial — build a guest-list app step by step.
• UI walkthrough — auth, tenant switching, language and theme toggles.
• publicstatus.eu — a full statuspage product built end to end on Kumiko, in production.

→ Ready to build your own? Quickstart — the starter includes a demo tasks UI out of the box. · Tutorial