Celeriant
An append-only event store for the write side of CQRS. Distributed, strictly ordered, built in Rust.
Celeriant enforces business invariants at write time across many streams: optimistic concurrency, idempotent retries, per-aggregate ordering, and cluster-wide durability. 1,057,417 durable writes a second across 60,000 connections, p99 108 ms end-to-end over mTLS, every write fsync'd on both nodes before the ack. See Performance.
Start here
- Quickstart: run a node and append your first event in five minutes.
- What is Celeriant: the problem it solves, and how.
- When not to use it: read this before you adopt anything.
- Concepts: CQRS, aggregates, events.
Celeriant is pre-1.0. The wire format can still change between releases, and the open-source binaries ship with the Apache-2.0 release. If you need stability today, see when not to use it.
Why every page says LLM generated
An LLM wrote the prose on this site. I read every page and the content is correct: each load-bearing claim traces back to the Celeriant source, and anything that drifts gets fixed.
What I have not done is rewrite it all in my own voice. Building the database wins that fight for my time, every week. Sorry for the machine prose. If you do find something wrong, open an issue and I will fix it.