# X Article Draft: Zaxy 2.3.0

Zaxy 2.3.0 is out: the embedded engine moves off archived infrastructure, and nothing you rely on moves with it.

The short version: Zaxy's default local graph runtime was built on Kuzu, which shipped its final release and archived its repository — no more fixes, no more wheels for new Python versions. 2.3 moves the embedded backend to LadybugDB, the maintained fork of the same engine lineage, and keeps the `PROJECTION_BACKEND=embedded` contract, the schema, query semantics, and the ANN engagement defaults exactly where 2.2 left them.

Depending on a dead dependency is a slow-motion outage. But swapping the engine under a memory system is also exactly how you lose someone's data if you are careless about it. So the rule for this release was: the source of truth never moves, and the migration deletes nothing.

How the move works:

- Eventloom — the append-only, hash-chained log — is untouched. It was always the source of truth; projections were always rebuildable from it. That design is what makes an engine swap a projection-layer change instead of a data migration.
- On first open of a pre-fork projection file LadybugDB cannot read, Zaxy moves it (and its WAL) aside to `<path>.pre-ladybug.bak` — no data deleted — opens a fresh store, and rebuilds from the log via `zaxy reproject`. `zaxy doctor` reports the leftover backup until you have verified the rebuild and chosen to delete it.
- The move also collects a dividend: LadybugDB fixed the upstream `DROP_VECTOR_INDEX` corruption defect 2.2 had to work around, so superseded ANN index generations are now dropped for full space reclaim.

Now the part that is the reason to trust the rest of it.

The release branch arrived with a confident comment in the code: the vector index extension was "statically linked, offline-safe, no INSTALL needed." It was wrong. LadybugDB ships the vector index as a downloadable extension, not a bundled one. It happened to work on the machine that built the release — because that machine had the extension cached from earlier use — and it would have silently failed on every fresh install, disabling approximate search for new users while swallowing the error.

Nothing in a human read of the diff would have caught that. What caught it was the coverage ratchet: on a clean CI runner the extension was absent, the native vector tests skipped, and total coverage slipped 0.02% under the floor. A two-hundredths-of-a-percent tripwire is the only thing standing between "looks done" and a marquee feature that is dead on arrival. We traced the skip to the missing extension, reproduced the fresh-machine condition locally, and fixed the cause: the store now installs-then-loads the extension, cached after first use, and degrades to exact search with a clear warning when it genuinely cannot.

A note on framing, because we got it wrong first and corrected it: this is local-first, not offline-only. A one-time extension fetch that then runs entirely on-box is no more a network dependency than `pip install` itself — the data, the engine, and the compute all stay local. The default exact-search path is pure NumPy and fetches nothing. Air-gapped deployments that want approximate search pre-seed the extension cache; everyone else never notices.

The claim boundary, as always: the engine swap was gated on a readiness-research pass and lane reruns that reproduced 2.2's deterministic evidence — identical corpus hashes and recall — with raw artifacts versioned in the repo. The fork is single-maintainer and the dependency pin is exact on purpose; that is what depending on infrastructure honestly looks like, archived or forked.

Release: https://github.com/syndicalt/zaxy/releases/tag/v2.3.0 Migration: https://docs.zaxy.io/docs/migration.html Install: `pip install zaxy-memory`

Zaxy is event-sourced memory for agent work: a hash-chained append-only log as the source of truth, cited Memory Checkout as the trust contract, and a runtime where the engine is replaceable because the log is authoritative. https://docs.zaxy.io