omnigraph/docs/releases/v0.6.0.md

# Omnigraph v0.6.0

Two pieces of work land in this release:

1. The **graph terminology rename** (renamed `Repo` → `Graph` across the Cedar resource model, policy API, and query-lint schema source).
2. **Multi-graph server mode** (MR-668) — one `omnigraph-server` process can now serve 1–10 graphs concurrently behind cluster routes (`/graphs/{graph_id}/...`), with per-graph and server-level Cedar policy, read-only `GET /graphs` enumeration, and CLI parity (`omnigraph graphs list`).

Runtime add/remove (`POST /graphs`, `DELETE /graphs/{id}`, `omnigraph graphs create`) is **not** in v0.6.0. Operators add or remove graphs by editing `omnigraph.yaml` and restarting. The first cut of `POST /graphs` shipped behind an atomic-YAML-rewrite design that we pulled before release once its concurrency guarantees were challenged (flock-on-renamed-inode race, duplicate-check outside the critical section, and an init-cleanup path that could destroy an existing graph's schema on re-init). The correct fix is a Lance-style cluster catalog (reserve → init → publish with recovery sidecars); that work is deferred.

## Breaking Changes

### Graph terminology rename

- Renamed the Cedar resource entity from `Omnigraph::Repo` to `Omnigraph::Graph`.
- Renamed policy API terminology from `repo_id` to `graph_id` on `PolicyCompiler::compile` (and on the new `PolicyEngine::load_graph` / `PolicyEngine::load_server` loaders described below).
- Renamed query-lint schema source JSON from `"repo"` to `"graph"` for `schema_source.kind`.

### Multi-graph server mode

- **Multi-graph deployments lose flat routes.** Single-graph invocation (`omnigraph-server <URI>`) is unchanged — same flat `/snapshot`, `/read`, `/branches`, etc. Multi-graph deployments serve those routes under `/graphs/{graph_id}/...`; bare flat paths return 404 in multi mode.
- **`ServerConfig` shape change** (programmatic embedders only): `ServerConfig { uri, policy_file }` is replaced by `ServerConfig { mode: ServerConfigMode }`, where `ServerConfigMode = Single { uri, policy_file } | Multi { graphs, config_path, server_policy_file }`. Callers that use `load_server_settings` are unaffected; callers that construct `ServerConfig` directly need to wrap their fields in `ServerConfigMode::Single`.
- **`AppState`'s routing surface** is `AppState::routing() -> &GraphRouting`, where `GraphRouting = Single { handle } | Multi { registry, config_path }`. The previous `AppState::uri()`, `AppState::mode()`, `AppState::registry()` accessors and the `ServerMode` enum are gone — embedders read `state.routing()` and match on the arm they need. Per-graph URIs live on `handle.uri`.
- **`AppState::new_multi`** is the new multi-graph constructor. Single-mode `new_*` / `open_*` constructors are unchanged.
- **`AuthenticatedActor(Arc<str>)` → `ResolvedActor { actor_id, tenant_id, scopes, source }`** (programmatic embedders only). The struct shape changes, but the HTTP contract — bearer auth, MR-731 spoof defense — is unchanged. Cluster-mode call sites construct with `tenant_id: None`, `scopes: vec![Scope::Full]`, `source: AuthSource::Static`. Forward-compat for Cloud mode (RFC 0003) and OAuth provider (RFC 0004).
- **`PolicyEngine::load(path, graph_id)` removed** in favor of two kind-typed loaders: `PolicyEngine::load_graph(path, graph_id)` for per-graph policies and `PolicyEngine::load_server(path)` for server-level policies. Each loader rejects rules whose action `resource_kind()` doesn't match the engine kind — operators who put a `graph_list` rule in a per-graph file (or a `read` rule in a server file) now get a load-time error instead of a silently-never-matching rule.
- **`PolicyRequest::actor_id` field removed.** Actor identity is now a separate parameter on `PolicyEngine::authorize(actor_id, &request)`. The type system enforces MR-731's server-authoritative-actor invariant — handlers cannot smuggle identity through the request body.
- **`Omnigraph::init` is strict by default.** Initialization at a URI that already holds schema files now errors with `OmniError::AlreadyInitialized` instead of silently overwriting. Operators who actually want to overwrite use `InitOptions { force: true }` (CLI: `omnigraph init --force`). Closes the destructive-cleanup footgun where a failed re-init would delete an existing graph's schema files.

## New

- **Multi-graph mode**. Invoke with `omnigraph-server --config omnigraph.yaml` where the YAML has a non-empty `graphs:` map and no single-mode selector (no `server.graph`, no CLI `<URI>` or `--target`). At startup the server opens every configured graph in parallel (bounded concurrency, fail-fast).
- **`GET /graphs`**. Lists every registered graph, sorted alphabetically by `graph_id`. Auth-required when bearer tokens are configured; Cedar-gated by `PolicyAction::GraphList` against `Omnigraph::Server::"root"`. Returns 405 in single mode. Server-scoped actions require an explicit `server.policy.file` in every runtime state — the management surface is closed by default even in `--unauthenticated` mode so that server topology is never exposed without operator opt-in.
- **CLI `omnigraph graphs list`**. Mirrors the HTTP surface. Rejects local URI targets with a clear message — for remote multi-graph servers only.
- **CLI `omnigraph init --force`**. Bypasses the strict-init preflight when an operator deliberately wants to recover from orphan schema files. Does NOT purge existing Lance datasets; recursive deletion needs `StorageAdapter::delete_prefix` (deferred — see below).
- **Per-graph Cedar policy**. Each entry in the `graphs:` map can carry a `policy.file` path, loaded at startup via `PolicyEngine::load_graph`. Cedar's `Omnigraph::Graph::"<graph_id>"` resource is per-graph; the new `Omnigraph::Server::"root"` resource governs server-level actions.
- **Server-level Cedar policy**. `server.policy.file` in the config governs the `graph_list` action on `Omnigraph::Server::"root"`. Required to expose `GET /graphs` once bearer tokens are configured (MR-723 default-deny otherwise rejects `graph_list` as non-`read`).
- **Cedar action vocabulary**: `graph_list` (server-scoped). Runtime `graph_create` / `graph_delete` are reserved but not shipped — see "Deferred."
- **Startup invariant: policy requires tokens.** Configuring any policy file (per-graph or server-level) without bearer tokens now refuses to boot — `serve()` would otherwise start a server that 401s every request. The check lives in `classify_server_runtime_state` and applies uniformly to single and multi mode.

## Configuration

`omnigraph.yaml` schema additions (all optional, single-mode unaffected):

```yaml
server:
  bind: 0.0.0.0:8080
  policy:
    file: ./server-policy.yaml          # server-level Cedar (graph_list)

graphs:
  alpha:
    uri: s3://tenant-bucket/alpha
    policy:
      file: ./policies/alpha.yaml       # per-graph Cedar
  beta:
    uri: s3://tenant-bucket/beta
    # no per-graph policy → engine-layer enforcement is a no-op
```

## Deferred

- **`POST /graphs` runtime graph creation** and **CLI `omnigraph graphs create`**. Pulled before release after the YAML-rewrite design's correctness story didn't survive review. A future release will add a managed cluster catalog (Lance-backed reserve → init → publish with recovery sidecars) and re-expose runtime creation on top of it. Until then, operators add graphs by editing `omnigraph.yaml` and restarting.
- **`DELETE /graphs/{id}`**. Never shipped in v0.6.0; deferred with the same cluster-catalog work.
- **`StorageAdapter::delete_prefix`**. The substrate primitive a managed catalog would need. Will land alongside runtime mutation.
- **`omnigraph init --force` purging Lance state.** Today `--force` only bypasses the schema-file preflight; recursive deletion of existing Lance datasets needs `delete_prefix`.
- **`X-Actor-Id` service delegation forwarding**. Needs durable both-actor audit on `_graph_commits.lance` — out of scope.
- **Hot policy reload**. Restart is cheap at N≤10 graphs.

## User Impact

- **No on-disk migration is required.** Existing `.omni` graphs from v0.5.0 (and earlier) open cleanly under v0.6.0 — Lance datasets, `__manifest`, `_schema.pg`, `_schema.ir.json`, `__schema_state.json`, `_graph_commits.lance`, `_graph_commit_recoveries.lance` all use unchanged formats. No conversion step.
- **Existing single-graph deployments upgrade with zero changes.** `omnigraph-server <URI>` with v0.5.0 config keeps working identically.
- **Multi-graph adoption is opt-in.** Add a `graphs:` map to `omnigraph.yaml` (and remove `server.graph`) to switch a deployment to multi mode.
- **Cluster routes are breaking for client SDKs targeting multi mode.** Generated clients from previous v0.5.0 OpenAPI specs will hit 404 on flat paths against a multi-mode server. Regenerate against the v0.6.0 `openapi.json`.
- **Supported YAML policy authoring is unchanged.** The Cedar `Omnigraph::Graph` and `Omnigraph::Server` entities are internally generated by `compile_policy_source` — operator YAML only references actions and groups.
- **Operators with unsupported raw Cedar policy files** should update `Omnigraph::Repo` resource references to `Omnigraph::Graph`.

## Migration: single → multi

```yaml
# Before (v0.5.0 single-mode invocation)
server:
  graph: my-graph
graphs:
  my-graph:
    uri: /var/lib/omnigraph/my-graph
policy:
  file: ./policy.yaml
```

```yaml
# After (v0.6.0 multi-mode — drop `server.graph` and the top-level `policy`)
server:
  policy:
    file: ./server-policy.yaml      # NEW: governs GET /graphs
graphs:
  my-graph:
    uri: /var/lib/omnigraph/my-graph
    policy:
      file: ./policy.yaml           # MOVED: was top-level
```

Same `omnigraph.yaml` file; restart the server. Clients targeting the old flat routes (`/snapshot`, `/read`, …) must update to `/graphs/my-graph/snapshot`, etc.

To add a new graph after rollout: stop the server, append a new `graphs.<id>` entry, restart.

## Documentation

- Public docs, CLI help, examples, server docs, and test helpers now consistently use "graph" for the OmniGraph data artifact.
- GitHub/source repository terminology remains spelled out as "repository" where needed.
- New: `docs/user/cli.md` documents `omnigraph graphs list`; `docs/user/server.md` documents the multi-graph mode and the cluster route convention; `docs/user/policy.md` documents the per-graph vs server-scoped action distinction.

## Test coverage

- `GraphId` newtype validation, registry race tests, init failpoints (still reachable from `omnigraph init` CLI).
- Mode-inference four-rule matrix, parallel multi-graph startup, cluster routing.
- Cedar `Server` resource refactor, backwards-compat for graph-only policies, kind-alignment rejection (server actions in graph files / vice versa).
- `GET /graphs` enumeration, 405-in-single-mode, 403-in-Open-mode-without-server-policy, Cedar admin/viewer authorization.
- Cluster routes with inner path params (`/branches/{branch}`, `/commits/{commit_id}`) deserialize correctly under axum 0.8 nested routing.
- Policy-requires-tokens startup invariant enforced uniformly across single and multi mode.
- MR-731 spoof regression test stays green across the entire refactor.
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