Casita publishes a content-addressed store for source and build artifacts as the first standalone layer of a Nix rewrite in Rust

Sources: primary, discussion
Summary: Domen Kozar's 2026-09-27 post presents the storage layer on its own terms: BLAKE3-addressed immutable blobs with an optional Bao outboard so a reader can verify one range without reading the whole blob, object records forming a graph above them, and named roots that drive synchronisation and garbage collection. Importers cover filesystem, tar, NAR and native Git, keeping each format's own identity, so a Git commit holds its SHA while Casita addresses its body bytes. The stated motivation is agentic development filling disks with target directories, and the retention answer is an evictable root plus automatic collection that triggers at 80 percent full and releases least-recently-used evictable roots until use falls below 75 percent.
Why it matters: The Cargo ArtifactStorage backend is experimental, the post states its import and restore performance has not yet matched the filesystem backend, and v0.1.0 is untagged, so this is a design to read rather than a dependency to adopt.