Open source

Our scheduling engine is open.

The core that resolves availability, distributes bookings and handles time zones is MIT-licensed and developed in public. The roadmap is transparent, pull requests are reviewed by humans, and the hosted product improves with every upstream patch.

Star on GitHub

MIT-licensed — fork it, ship it, embed it
Public roadmap discussed in weekly open triage
First-time contributors welcome, docs first

0%MIT open-source license

0proprietary vendor lock-in

0%concurrency protection

0%developer API access

PostgreSQL advisory locks Self-hostable engine MIT license

Why open

Code you can read is code you can trust

Scheduling is infrastructure. Infrastructure deserves daylight — not a terms-of-service paragraph.

Auditability

Read exactly how availability is resolved, how round-robin distributes and what is stored. Security teams can review the engine line by line instead of taking our word for it.

Self-host friendly core

The scheduling engine — availability math, booking logic, time zone handling — runs on your own infrastructure if you want it to. No features hidden behind a license key.

Community roadmap

Issues are public, priorities are discussed in the open, and the changelog ships with contributor credits. Good ideas come from people we have never met.

Get involved

Three steps to your first commit

You do not need to be a scheduler nerd. Most first PRs are docs, tests or a small fix — and all of them count.

Read the docs

Architecture notes, local setup and a glossary of the domain — written so a first-time contributor can be productive on day one.

Pick a good-first-issue

Every issue labeled good-first-issue is triaged, scoped and unclaimed. Tests and context included — no archaeology required.

Open a PR

A maintainer reviews within 48 hours, CI runs the full suite, and your name lands in the release notes of the next ship.

terminal — semiora/core

# clone the engine
$ git clone semiora/core

# run the availability engine locally
$ cd core && bun install
$ bun dev --engine
ready — availability engine on localhost:4000

# your first PR starts here
$ bun issues --label good-first-issue
23 open · 7 claimed · last pick 2 days ago

docs.semiora.app/core 48h review SLA

Open, and open for business

Use the hosted app, or run the core yourself.

Either way you get the same availability engine, the same booking pages and the same built-in chat. The fence between them is a one-line license.

Free forever for individuals · Pro from $12/seat · Cancel anytime