# Omnigraph v0.8.0

The first release with an on-disk format change since v0.4.0. Graph commit
lineage now lives in `__manifest`, the two legacy commit-graph datasets are
gone, constraint validation is unified (and stricter in a few cases), and the
storage-format version is now visible to operators. **Storage is
strict-single-version: a graph from an older release is rebuilt via
export/import, not migrated in place.** Read the upgrade notes before rolling out.

## Highlights

- **Graph lineage moved into `__manifest` (internal schema v4).** The commit DAG
  (commits, parents, branch heads, actor) is now written in the same atomic
  commit as a graph's table-version rows, closing the crash window where a
  manifest version could exist without its lineage. The two legacy datasets
  (`_graph_commits.lance`, `_graph_commit_actors.lance`) are no longer created or
  read — one fewer moving part and two fewer directory listings per open.

- **Stricter, unified constraint validation.** The loader, mutation, and
  branch-merge paths now share one validator, so they can no longer drift. All
  changes are stricter (none relax an existing check): enum constraints are
  enforced on merge, a `@unique` value that collides with an already-committed
  different row is rejected, duplicate-key semantics are precise (a key repeated
  within one input batch is rejected; the same id across batches coalesces), and
  overwrite loads validate per touched table. A pipeline that unknowingly relied
  on one of these gaps will now fail loudly at write time.

- **Storage-format version is visible.** `omnigraph version` prints the format
  version this binary serves, `omnigraph snapshot` reports a graph's on-disk
  version, and the server `GET /healthz` response includes it.

- **Prebuilt linux-arm64 (aarch64) binaries** now ship alongside Linux x86_64,
  macOS arm64, and Windows x86_64, with a matching Homebrew bottle.

## Upgrade

- **Upgrade every binary that touches a graph to v0.8.0 together.** Older-format
  graphs are refused on open in both directions: a newer binary refuses an
  old-format graph, and an old binary refuses this one.
- **Any pre-v0.8.0 graph is rebuilt, not migrated:** export it with the old binary,
  then `init` + `load` with v0.8.0. Data, vectors, and blobs are preserved;
  commit history and branches are not carried over. See the
  [upgrade guide](../user/operations/upgrade.md).