Self-host calrs
v1.21.0Fast self-hosted scheduling platform in Rust
- Stars
- 331
- Port
- 3000 (HTTP web server)
- Requires
- CalDAV server
ghcr.io/olivierlambert/calrs
What is calrs?
calrs is a self-hosted scheduling platform built in Rust as a single binary with no external runtime dependencies. It connects to CalDAV servers (Nextcloud, Fastmail, BlueMind, iCloud, Zimbra, SOGo, Radicale) for free/busy sync and write-back of confirmed bookings, and also supports Google Calendar via OAuth2 and Microsoft Exchange via EWS. Users define event types with duration, buffers, minimum notice, and availability schedules; guests book through a public slot picker with timezone auto-detection. Features include team scheduling (round-robin or collective), three visibility levels (public, internal, private), dynamic group links, rescheduling without cancellation, booking limits, date overrides, availability troubleshooting, dark/light themes with 7 built-in presets, multi-language UI (9 languages), email notifications with .ics invites, SMS via Twilio/GatewayAPI/seven.io, Jitsi video rooms or custom webhook providers, optional self-hosted CAPTCHA (Cap), OIDC/SSO (Keycloak, Authentik), Argon2 password hashing, AES-256-GCM credential encryption, and a full CLI for headless operation. It listens on port 3000 by default, uses SQLite (WAL mode) for storage, and is deployed via Docker, Docker Compose, systemd, or bare binary. Licensed AGPL-3.0.
Should you self-host calrs?
calrs scores 53/100 on selfhost.directory (how scoring works) and ranks #9 of 30 in Calendar & Contacts. It has 331 GitHub stars.
It shipped 10 stable releases in the past year. The latest, v1.21.0, came out on 25 October 2026.
Setup is moderate: expect some configuration beyond a single command. An official Docker image is available. It is AGPL-3.0-licensed and written mostly in Rust.
Its closest alternative on selfhost.directory is Cal.dyi (81/100, 49 458 stars). It scores higher overall, so compare the two before you pick. See calrs vs Cal.dyi side by side.
Features
- Availability engine
- CalDAV Sync
- CalDAV write-back
- Dynamic group links
- Email notifications with .ics
- Event types
- Multi-language UI
- OIDC/SSO
- Rescheduling
- SMS Notifications
- Team scheduling
- Three-level visibility
- Timezone Support
- Video meeting links
calrs README
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