chore(release): 10.4.0-rc.2

repairIndex() acted only on heal:'rebuild' — an invariant asking for the
INCREMENTAL heal (re-post exactly what the ledger names, O(missing), never
a store-sized rebuild) did nothing on brainy's side. A failing 'repair'
verdict now routes to the provider's feature-detected repair(); the
post-heal RE-READ of the report decides success (the acceptance meta-pin's
law — run the named heal once, re-read, nothing may still fail the same
way), and a repair that does not converge is recorded with the escalation
named: repairIndex({ rebuild: [family] }).

CHANGELOG.md

@@ -2,6 +2,17 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+### [10.4.0-rc.2](https://source.soulcraft.com/soulcraft/brainy/compare/v10.4.0-rc.1...v10.4.0-rc.2) (2026-08-25)
+
+- test(readiness): the report helper's clock freezes — two independently-built reports compared across a millisecond tick made the plant lane red (39b916a3)
+- feat(repair): a heal:'repair' verdict routes to the provider's own incremental repair() (553e0d97)
+- fix(storage): an unknown nested storage config can never silently land on the shared default root (ddd5e719)
+- docs(release): the 10.4.0 entry, the index-health concept doc, and the API surfaces — written from the tree, not the plan (8cced871)
+- fix(plugins): the silent-degrade doors close — a broken accelerator install can never read as absent (b9ba50fb)
+- feat(recovery): the catchup verdict is consumed; verb rows go live; the metadata rebuild goes online (18f172e0)
+- feat(health): the gate reads the named report — reads refuse loudly, never rebuild; open serves before it returns; the ceremony door (f8f64780)
+
+
 ### [10.4.0-rc.1](https://source.soulcraft.com/soulcraft/brainy/compare/v10.3.1...v10.4.0-rc.1) (2026-08-24)
 
 - ci(publish): the home dist-tag follows the version — a prerelease publishes under 'rc' and never moves 'latest' (a1376e4a)

RELEASES.md

@@ -31,6 +31,90 @@ is sometimes cited as a 7.x removal — those methods never existed on 7.x; the
 
 ---
 
+## v10.4.0 — 2026-08-25 (the health report has a name)
+
+Three related cures, one root cause: an index deciding whether it could be trusted
+by sampling itself instead of by exact accounting. This release replaces every
+sampled self-probe with ledger-derived truth, and a read against an unhealthy index
+now refuses loudly instead of guessing.
+
+- **The canonical count ledger.** Storage now tracks two scalars per family
+  (nouns/verbs) on the write path: the user-facing `counted` total — unchanged,
+  still what `getNounCount()` / `getVerbCount()` return — and a new ALL-visibility
+  `all` total covering every tier, the real denominator a derived index's own
+  coverage math needs. The unfiltered storage-level `totalCount` returned by
+  `getNouns()` / `getVerbs()` is now this unclamped ALL scalar; previously it could
+  only ever move up (`Math.max(scalar, scanned)`), so an inflated counter could
+  never self-correct. A delete that cannot prove the record it removed actually
+  existed (no canonical read, no prior image available) no longer decrements on
+  faith — it marks the ledger `suspect` (narrated once per session) instead of
+  silently drifting, and the next `repairIndex()` clears the flag with a real
+  recount.
+- **One contract for a throwing health probe.** A provider's `validateInvariants()`
+  is documented to never throw — but if one does anyway (a bug, a transient fault),
+  it is now read the same way everywhere: `heal: 'none'`, the error named in the
+  report, never synthesized into a rebuild trigger and never swallowed into "looks
+  fine." A flaky check can no longer buy itself a rebuild. `repairIndex()`'s
+  per-family receipt also gains `missing` (an exact count plus a capped id sample),
+  `rebuilt` (a full rebuild ran, vs. an incremental heal), and `reason`.
+- **The named health report; reads refuse instead of rebuilding.** Any index
+  provider may now expose a synchronous, O(1) `healthReport()` — composed from the
+  provider's own exact ledgers, never a sample — and this is the one signal
+  Brainy's read gate trusts. The first-query lazy-build path is gone: `brain.init()`
+  now runs every needed rebuild to completion before it returns, always, regardless
+  of dataset size. A read that lands on a provider whose health report says it
+  isn't serving throws a typed error instead of triggering a rebuild mid-query —
+  `GraphIndexNotReadyError`, `MetadataIndexNotReadyError`, or
+  `VectorIndexNotReadyError` (all exported from `@soulcraft/brainy`), naming the
+  reasons. `repairIndex({ rebuild: ['metadata' | 'graph' | 'vector'] | 'all' })` is
+  the new explicit operator door: it rebuilds the named family unconditionally, no
+  health check consulted — reach for it when you have independent reason to
+  distrust a family regardless of what it self-reports. Bare `repairIndex()` is
+  unchanged in spirit: report-driven, heals only what its own checks say needs it.
+- New concept doc: [Index Health](docs/concepts/index-health.md) walks the whole
+  story from a consumer's side — degraded-but-serving vs. not-ready, what
+  `repairIndex()` checks and heals per family, what `suspect` counts mean.
+
+**Nothing to change to adopt this.** No API removed, no signature narrowed —
+`repairIndex()` gains an optional options bag and its return value gains fields,
+both additive. The honest notes: if your code ever relied on a `find()` against a
+cold/not-yet-built index quietly triggering a rebuild and returning results a beat
+later, that behavior is gone — it now throws one of the three typed
+`*NotReadyError` classes instead (catch them if you need to distinguish "not ready
+yet" from "no results"). And `disableAutoRebuild: true` no longer defers index
+construction to the first query — a needed rebuild always runs at `open()` now;
+the flag has no effect on timing. Full manual control still lives in
+`repairIndex({ rebuild: [...] })`.
+
+- **Crash-reopen catchup.** After an unclean shutdown, the metadata index now
+  folds the exact fact window it missed — `find()` serves every acked write on
+  reopen, closing the gap where canonical reads and counts recovered a
+  crash-window write but the index kept serving its pre-crash state until the
+  next full rebuild. Related root-cause fixed alongside: `close()` never
+  stamped the index watermarks (only `flush()` did), so a close without a
+  prior flush caused a needless full rescan verdict on the next open.
+- **Relation rows are live in the metadata index.** Previously verb rows
+  entered the metadata index only during a rebuild — so a rebuilt store's
+  relation postings went stale from the first `relate()` after it. Relations
+  are now posted and retracted on the live write path (relate / unrelate /
+  updateRelation / remove's cascade, and their `transact()` forms), in the
+  same commit as the graph leg.
+- **The metadata rebuild is online.** `rebuild()` for the metadata family no
+  longer clears and rebuilds in place (reads went empty for the duration): it
+  builds a complete replacement beside the serving index, mirrors concurrent
+  writes to both, swaps atomically, and persists once after the swap. Reads
+  never observe a partial index. `repairIndex({ rebuild: ['metadata'] })` uses
+  it automatically.
+- **A broken accelerator install can never read as "not installed."** The
+  auto-detection free pass now requires the resolution error to name the
+  accelerator package itself, exactly — a missing platform-binary sibling
+  package, an inner file path, or a dependency failure is a broken install and
+  `init()` throws loudly. And a plugin that declines activation is narrated on
+  the always-on log channel, so `silent: true` can no longer hide a fallback
+  to the default engines.
+
+---
+
 ## v10.3.1 — 2026-08-18 (the fold that behaves)
 
 Three recovery cures from one production first-boot incident (a brain's first

docs/PERFORMANCE.md

@@ -323,58 +323,24 @@ Only the graph adjacency index carries a committed scale assertion:
 - ✅ **Single-Node by Design**: One process owns one `path`; scale out at the service layer
 - ✅ **Zero Stubs**: Every line of code is production-ready
 
-## Lazy Loading Performance
+## Index Build at Open (10.4+)
 
-Brainy supports two initialization modes for optimal performance across different use cases:
+As of 10.4, `brain.init()` runs every needed index rebuild to completion before
+it returns — always, regardless of dataset size. There is no lazy,
+first-query rebuild path: a brain either finishes opening healthy, or `init()`
+fails loudly. `disableAutoRebuild` no longer defers index construction to a
+first query; it has no effect on *when* a rebuild runs. Manual control over
+rebuilds is `repairIndex({ rebuild: [...] })`. See
+[Index Health](concepts/index-health.md) for the full read-gate contract
+(providers self-report readiness via `healthReport()`; a read against a
+not-serving provider throws a typed `*NotReadyError` rather than rebuilding
+mid-query).
 
-### Mode 1: Auto-Rebuild (Default)
+<!-- The pre-10.4 "Mode 2: Lazy Loading on First Query" section previously
-
+     documented here (disableAutoRebuild deferring index construction to the
-```javascript
+     first find() call) described a real, now-retired code path. Removed
-const brain = new Brainy()
+     rather than left to mislead; the concept doc above is the current
-await brain.init()  // Rebuilds indexes during init (~500ms-3s for 10K entities)
+     contract. -->
-```
-
-**Performance:**
-- Init time: 500ms-3s (depends on dataset size)
-- First query: Instant (indexes already loaded)
-- Use case: Traditional applications, long-running servers
-
-### Mode 2: Lazy Loading
-
-```javascript
-const brain = new Brainy({ disableAutoRebuild: true })
-await brain.init()  // Returns instantly (0-10ms)
-
-const results = await brain.find({ limit: 10 })  // First query triggers rebuild (~50-200ms)
-const more = await brain.find({ limit: 100 })    // Subsequent queries instant (0ms check)
-```
-
-**Performance:**
-- Init time: 0-10ms (instant)
-- First query: 50-200ms (includes index rebuild for 1K-10K entities)
-- Subsequent queries: 0ms check (instant)
-- Concurrent queries: Wait for same rebuild (mutex prevents duplicates)
-
-**Concurrency Safety:**
-```javascript
-// 100 concurrent queries immediately after init
-await brain.init()
-
-const promises = Array.from({ length: 100 }, () =>
-  brain.find({ limit: 10 })
-)
-
-const results = await Promise.all(promises)
-// ✅ Only 1 rebuild triggered (mutex)
-// ✅ All 100 queries return correct results
-// ✅ Total time: ~60ms (not 6000ms!)
-```
-
-**Use Cases for Lazy Loading:**
-- **Serverless/Edge**: Minimize cold start time (0-10ms init)
-- **Development**: Faster restarts during development
-- **Large datasets**: Defer index loading until needed
-- **Read-heavy workloads**: Writes don't wait for index rebuild
 
 ## Zero Configuration Required
 
@@ -384,10 +350,6 @@ Brainy is designed to be **smart enough to tune itself dynamically**. No configu
 // That's it. Brainy handles everything.
 const brain = new Brainy()
 await brain.init()
-
-// Or with lazy loading for serverless
-const brain = new Brainy({ disableAutoRebuild: true })
-await brain.init()  // Instant (0-10ms)
 ```
 
 ### Automatic Self-Tuning
@@ -395,7 +357,6 @@ await brain.init()  // Instant (0-10ms)
 - **Metadata Index**: Auto-builds sorted indices for range queries on first use
 - **Graph Index**: Auto-flushes every 30 seconds
 - **Default Tuning**: Research-based vector index defaults
-- **Lazy Loading**: Indices built only when needed
 - **Cache Management**: LRU caches with TTL
 
 ### Intelligent Defaults

docs/PLUGINS.md

@@ -10,7 +10,7 @@ next:
   - guides/storage-adapters
 ---
 
-# Plugin Development Guide
+# Plugin System
 
 Brainy has a plugin system that allows third-party packages to replace internal subsystems with custom implementations. This is how `@soulcraft/cor` provides optional native acceleration, and it's the same system available to any developer.
 
@@ -200,15 +200,30 @@ members so a warm reopen never pays a redundant rebuild-from-canonical:
 - **`init?(): Promise<void>`** — eager cold-load. Brainy awaits it once during
   `brain.init()`, after the metadata provider's `init()` (the id-mapper hydrates first)
   and **before the rebuild gate**.
-- **`isReady?(): boolean`** — honest durability signal. `true` ⇔ the persisted index is
+- **`healthReport?(): HealthReport`** — the PREFERRED signal (10.4+). A named,
-  loaded (or cheaply demand-loadable) and consistent with what was last persisted. When
+  synchronous, O(1) verdict derived from the provider's own exact ledgers — never a
-  exposed, the rebuild gate defers to this signal **instead of** the `size() === 0` /
+  sample, never I/O, must never throw for a well-formed provider. Brainy's read gate
-  `totalEntries === 0` heuristics — a disk-native index may report 0 resident entries
+  (`assessProviderHealth()`) reads this INSTEAD of `isReady()` / size heuristics when
-  while fully durable. Never return `true` if the durable state failed to load: the
+  present: `serving: false` refuses the read with a typed `*NotReadyError` rather than
-  signal is honest in both directions, and a not-ready provider gets its rebuild even
+  triggering a rebuild — a read never starts a store walk. `healthy` marks every
-  when `size() > 0`.
+  *verified* invariant holding; a family named in `unledgered` counts as neither
+  healthy nor broken. See `HealthReport` / `LedgerInvariantResult` /
+  `InvariantSource` in `src/plugin.ts`, and
+  [Index Health](concepts/index-health.md) for the consumer-facing story.
+- **`isReady?(): boolean`** — honest durability signal, the fallback when
+  `healthReport()` is absent. `true` ⇔ the persisted index is loaded (or cheaply
+  demand-loadable) and consistent with what was last persisted. When exposed, the
+  gate defers to this signal **instead of** the `size() === 0` / `totalEntries === 0`
+  heuristics — a disk-native index may report 0 resident entries while fully durable.
+  Never return `true` if the durable state failed to load: the signal is honest in
+  both directions, and a not-ready provider gets its rebuild even when `size() > 0`.
 - **`isMigrating?(): boolean`** — while `true`, the provider owns its index (background
   migration); brainy skips its rebuild entirely.
+- **`validateInvariants?(): Promise<ProviderInvariantReport>`** — the async DEEP
+  diagnostic (full scans allowed), distinct from the bounded, sync `healthReport()`.
+  Must never throw — a failure is `healthy: false` data, not an exception; a provider
+  that throws anyway is read as a loud, unverified failure (never as "healthy") by
+  every caller, never silently retried into a rebuild.
 
 Providers that implement none of these keep the size/count heuristics — correct for
 engines whose `rebuild()` *is* their load path (like brainy's built-in JS vector index).

docs/api/README.md

@@ -1451,6 +1451,34 @@ const count = await brain.getVerbCount()
 
 ---
 
+### The canonical count ledger (`StorageAdapter.getCanonicalCounts()`)
+
+An OPTIONAL method on the `StorageAdapter` interface (implemented by both
+built-in adapters), not a method on `Brainy` itself — relevant if you're
+writing a custom storage adapter or composing a provider's own
+`healthReport()`. O(1), no I/O. Per family (`nouns`/`verbs`):
+
+```typescript
+interface CanonicalCounts {
+  nouns: { counted: number; all: number }
+  verbs: { counted: number; all: number }
+  suspect: boolean
+}
+```
+
+- `counted` mirrors `getNounCount()` / `getVerbCount()` (public + internal tiers).
+- `all` is the ALL-visibility scalar — every tier, including system/internal
+  records — the denominator a derived index's own coverage math is measured
+  against.
+- `suspect` is `true` when an unprovable delete has left `all` unverified since
+  the last recount; `brain.repairIndex()` clears it with a real canonical walk.
+
+Adapters without the ledger omit the method; treat absence as "no
+denominator," never as zero. See
+**[Index Health](../concepts/index-health.md)** for the full story.
+
+---
+
 ### Subtype & facet APIs
 
 Full guide: **[Subtypes & Facets](../guides/subtypes-and-facets.md)**.
@@ -1831,6 +1859,104 @@ const semanticOnly = await brain.getStats({ excludeVFS: true })
 
 ---
 
+### `repairIndex(options?)` → `Promise<RepairReport>`
+
+The ceremony door for index repair. Bare `repairIndex()` is report-driven: it
+prunes orphaned containers, recomputes count rollups, reconciles VFS
+containment, and rebuilds only a derived-index family whose own health check
+asks for it. Pass `options.rebuild` to force one or more families to rebuild
+UNCONDITIONALLY — no health check is consulted — when an operator has
+independent reason to reconcile a family regardless of what it self-reports.
+
+```typescript
+// Report-driven: only heals what actually needs it
+const report = await brain.repairIndex()
+console.log(report.healedTotal, report.families)
+
+// Explicit: force the graph adjacency to rebuild from canonical, unconditionally
+await brain.repairIndex({ rebuild: ['graph'] })
+
+// Explicit: force all three derived indexes to rebuild
+await brain.repairIndex({ rebuild: 'all' })
+```
+
+**`RepairReport`:**
+- `families: RepairFamilyReport[]` — one row per family checked
+- `healedTotal: number` — items healed across every family
+- `durationMs: number`
+
+**`RepairFamilyReport`** (one row):
+- `family: string` — e.g. `'orphaned-containers'`, `'count-rollups'`,
+  `'vfs-containment'`, `'metadata-corruption'`, `'provider:metadata'`,
+  `'provider:graph'`, `'provider:vector'`
+- `checked: boolean` — was this family actually examined (`false` ⇒ see `skipped`)
+- `healed: number` — items re-posted/corrected in place (the incremental heal count)
+- `missing?: { count: number; sample: string[] }` — exact count plus a capped id
+  sample when the check can name what diverged (never the full list)
+- `rebuilt?: boolean` — a full generational rebuild ran (vs. an incremental heal)
+- `detail?: string` / `reason?: string` — narration
+- `skipped?: string` — why the family wasn't checked
+
+Full walkthrough — what each family checks, degraded-but-serving vs. not-ready,
+and what `suspect` counts mean — in
+**[Index Health](../concepts/index-health.md)**.
+
+---
+
+### Index readiness: typed errors, `healthReport()`, `disableAutoRebuild`
+
+Every derived-index provider (vector, graph, metadata) may expose a named,
+synchronous, O(1) `healthReport()` composed from its own exact ledgers — the
+signal Brainy's read gate trusts over sampling or size heuristics. `init()`
+brings every provider to serving before it returns; there is no first-query
+lazy-rebuild path. A read that reaches a provider whose health report says it
+isn't serving throws instead of rebuilding mid-query:
+
+| Error | Thrown by | Meaning |
+|---|---|---|
+| `GraphIndexNotReadyError` | `find({ connected })`, `neighbors()`, `related()` | Graph adjacency isn't serving |
+| `MetadataIndexNotReadyError` | `find({ where })` | Metadata/field index isn't serving |
+| `VectorIndexNotReadyError` | `find({ query })`, `similar()` | Vector index isn't serving |
+
+All three are exported from `@soulcraft/brainy`. Catch them to distinguish
+"index not ready" from a genuine empty result:
+
+```typescript
+import { MetadataIndexNotReadyError } from '@soulcraft/brainy'
+
+try {
+  const rows = await brain.find({ where: { status: 'active' } })
+} catch (err) {
+  if (err instanceof MetadataIndexNotReadyError) {
+    // reconcile: await brain.repairIndex(), then retry
+  } else {
+    throw err
+  }
+}
+```
+
+**`disableAutoRebuild`** no longer defers index construction to the first
+query. A needed rebuild always runs at `open()`, regardless of this flag or
+dataset size; the flag has no effect on *when* a rebuild runs. Full manual
+control lives in `repairIndex({ rebuild: [...] })`, above.
+
+### `validateIndexConsistency()` → `Promise<...>`
+
+The deep, async diagnostic counterpart to `healthReport()` — safe to run on a
+live brain, but does more work (a provider's `validateInvariants()` may run a
+full scan, not just read a ledger). Aggregates the JS metadata index's own
+consistency check with every derived-index provider's invariant report.
+
+```typescript
+const validation = await brain.validateIndexConsistency()
+if (!validation.healthy) {
+  console.log(validation.recommendation) // what to run, e.g. repairIndex()
+  console.log(validation.providers)      // each provider's own invariant report, when exposed
+}
+```
+
+---
+
 ## Lifecycle
 
 ### Initialization

docs/architecture/index-architecture.md

@@ -723,6 +723,14 @@ async stats(): Promise<Statistics> {
 
 ### 5. Index Rebuilding (Lazy Loading Support)
 
+> **Stale as of 10.4 — "Mode 2: Lazy Loading on First Query" below is
+> RETIRED.** `disableAutoRebuild` no longer defers index construction to a
+> first query; `brain.init()` now runs every needed rebuild to completion
+> before it returns, unconditionally, and a read against a not-serving
+> provider throws a typed `*NotReadyError` instead of rebuilding mid-query.
+> See `docs/concepts/index-health.md` for the current contract. Left below
+> as historical background on the rebuild mechanics.
+
 **Two modes of index loading:**
 
 #### Mode 1: Auto-Rebuild on init() (default)

docs/architecture/initialization-and-rebuild.md

@@ -1,5 +1,15 @@
 # Initialization and Rebuild Processes
 
+> **Stale as of 10.4 — "Mode 2: Lazy Loading on First Query" below is RETIRED.**
+> `disableAutoRebuild` no longer defers index construction to a first query;
+> `brain.init()` now runs every needed rebuild to completion before it
+> returns, unconditionally. A read against a not-serving provider throws a
+> typed `*NotReadyError` instead of rebuilding mid-query. See
+> `docs/concepts/index-health.md` for the current contract; this document's
+> line-number references to `src/brainy.ts` also predate the file's current
+> size and are unreliable. Left as historical background on the rebuild
+> mechanics, not as a current API description.
+
 This document explains how Brainy's four indexes (MetadataIndex, vector index, GraphAdjacencyIndex, DeletedItemsIndex) initialize and rebuild from persisted storage.
 
 ## Core Principle: All Indexes Are Disk-Based

docs/concepts/index-health.md

@@ -0,0 +1,204 @@
+---
+title: Index Health
+slug: concepts/index-health
+public: true
+category: concepts
+template: concept
+order: 8
+description: How Brainy knows whether a derived index can be trusted — exact accounting instead of sampling, the named health report, degraded-but-serving vs. not-ready, and what repairIndex() checks, heals, and rebuilds.
+next:
+  - concepts/generation-fact-log
+  - guides/inspection
+---
+
+# Index Health
+
+Brainy keeps one **canonical** copy of every entity and relationship, and three
+**derived** indexes built from it — vector, metadata, and graph — so `find()` can
+answer semantically, by filter, and by traversal without re-deriving the answer from
+scratch on every query. A derived index is a cache with a serving structure: it can
+be present but stale, present but only partially loaded, or fully out of sync with
+canonical after a crash. This page is about how Brainy decides whether to trust one,
+what it does when it can't, and how you reconcile the two.
+
+## Exact accounting instead of sampling
+
+Older health checks worked by inference: does `size()` return something greater
+than zero, does a spot-check on one known item come back correct. Both are proxies.
+A cold index can report a nonzero count while its actual serving structure never
+loaded, and a spot-check only proves the one item it happened to ask about.
+
+Every derived-index provider may now expose a named, synchronous, O(1)
+`healthReport()` — composed from the provider's own **exact ledgers** (real counters
+it already maintains on the write path), never a sample or a walk. This is the one
+signal Brainy's read gate consults. A provider that doesn't yet expose one falls
+back to an honest `isReady()` boolean, and finally to a size heuristic for engines
+with neither — but wherever a `healthReport()` exists, it wins.
+
+Underneath, storage itself keeps an analogous **canonical count ledger**: a
+`counted` scalar (the user-facing total — what `getNounCount()` / `getVerbCount()`
+return) and an `all` scalar (every tier, including internal records a derived
+index's own coverage math needs to compare against). This is the real denominator
+a provider's `healthReport()` measures itself by, rather than a total that can only
+ever ratchet upward. See [What `suspect` counts mean](#what-suspect-counts-mean)
+below for the one case that ledger can't stay exact through on its own.
+
+## The named report
+
+A `HealthReport` carries, per provider (`'vector'` / `'graph'` / `'metadata'`):
+
+- **`healthy`** — `true` iff every *verified* invariant holds. An invariant whose
+  family has no ledger yet is `unledgered`, never counted either way — unknown,
+  not passing.
+- **`serving`** — can this provider answer a query right now. A failing invariant
+  graded `heal: 'repair'` or `heal: 'none'` still leaves `serving: true` — this is
+  **degraded-but-serving**: something is off (say, a stale rollup on an
+  `employee` record's relationship count) but reads keep working. Only a failure
+  graded `heal: 'rebuild'` flips `serving` to `false` — **not-ready** — because the
+  provider itself is telling you its serving structure cannot answer correctly.
+- **`invariants`** — each checked condition, with its provenance
+  (`source: 'ledger'` — an exact count; `'deep'` — a full scan, diagnostic-only;
+  `'unledgered'` — not yet tracked) and, for a failing one, an exact `missing`
+  count plus a capped sample of the affected ids — a verdict, never a dump.
+- **`generation`** — bumps on every ledger mutation and rebuild, so a caller can
+  cache a verdict per generation instead of re-deriving it.
+
+The distinction that matters day to day: `healthy: false` can be entirely benign —
+a maintenance window, a divergence `repairIndex()` will clean up on its own
+schedule. `serving: false` is not benign. It means this provider is refusing to
+answer, on its own word, right now.
+
+## Reads refuse — they never rebuild
+
+A query that reaches a not-serving provider does not trigger a rebuild from inside
+the read. Brainy retired that path deliberately: a rebuild kicked off by an ordinary
+`find({ where: { status: 'active' } })` call is a dark, unpredictable cost hiding
+behind a request that looks like a cheap read. Instead, the read throws a typed,
+catchable error naming the reason:
+
+| Error | Thrown when | Meaning |
+|---|---|---|
+| `GraphIndexNotReadyError` | `find({ connected })`, `neighbors()`, `related()` | The graph adjacency index isn't serving — traversal would otherwise return `[]` indistinguishable from "no relationships" |
+| `MetadataIndexNotReadyError` | `find({ where })` | The metadata/field index isn't serving — a filtered read would otherwise return `[]` indistinguishable from "no matches" |
+| `VectorIndexNotReadyError` | `find({ query })`, `similar()` | The vector index isn't serving — a semantic search would otherwise return `[]` indistinguishable from "nothing similar" |
+
+All three are exported from `@soulcraft/brainy`. Catch them where your application
+needs to distinguish "this index isn't ready yet" from "there's genuinely nothing
+here" — a health dashboard, a retry policy, an operator alert. The fix is always
+the same: reconcile the index, either by reopening the brain (which brings every
+provider to serving before `init()` returns — see the next section) or by calling
+`repairIndex()` explicitly.
+
+```typescript
+try {
+  const active = await brain.find({ where: { status: 'active' } })
+} catch (err) {
+  if (err instanceof MetadataIndexNotReadyError) {
+    // not a "no results" — the index itself refused; alert or retry after repair
+  } else {
+    throw err
+  }
+}
+```
+
+### Rebuilds happen at open, not on first query
+
+`brain.init()` runs every needed rebuild to completion **before it returns**,
+unconditionally, regardless of dataset size. There is no lazy, first-query
+rebuild path anymore — a brain either finishes opening healthy, or it fails
+open loudly. `disableAutoRebuild: true` no longer defers index construction to
+the first query: it has no effect on *when* a needed rebuild runs. Full manual
+control over rebuilds is `repairIndex({ rebuild: [...] })` (below), not this flag.
+
+## `repairIndex()` — checking and healing
+
+Bare `repairIndex()` is **report-driven**: it only heals what its own checks say
+actually needs it, and it always returns a full per-family receipt.
+
+```typescript
+const report = await brain.repairIndex()
+report.healedTotal   // total items healed across every family
+report.durationMs
+report.families       // one row per family checked
+```
+
+Each `RepairFamilyReport` row names what happened:
+
+- **`checked`** — was this family actually examined (`false` means skipped —
+  see `skipped` for why).
+- **`healed`** — items re-posted or corrected in place.
+- **`missing`** — when the check can name what diverged: an exact `count` plus a
+  capped `sample` of ids.
+- **`rebuilt`** — a full generational rebuild ran (as opposed to an incremental
+  heal).
+- **`detail`** / **`reason`** / **`skipped`** — the receipt's narration; a row is
+  always either checked or explains why it wasn't. Nothing is silent.
+
+On every call, bare `repairIndex()`:
+
+1. Prunes orphaned canonical containers left by a partial delete.
+2. Recomputes the count rollups from one canonical walk (unconditional — this is
+   also what clears a `suspect` ledger; see below).
+3. Reconciles VFS containment edges, if the VFS is initialized.
+4. Runs the metadata index's own corruption detection pass.
+5. Consults each of the three derived-index providers' own health check and
+   rebuilds only a family whose failing invariant actually asks for it
+   (`heal: 'rebuild'`) — never a provider that reports `healthy` or a lesser
+   grade.
+
+### The explicit rebuild door
+
+`options.rebuild` skips the health check and rebuilds one or more families
+**unconditionally** — the operator override for when you have independent reason
+to distrust a family regardless of what it self-reports (a suspicious deploy, a
+storage-layer incident, a support ticket that doesn't match what the health report
+says):
+
+```typescript
+// Force the graph adjacency to rebuild from canonical, no invariant consulted
+await brain.repairIndex({ rebuild: ['graph'] })
+
+// Force all three derived indexes
+await brain.repairIndex({ rebuild: 'all' })
+```
+
+A family named this way is recorded with `rebuilt: true` and
+`reason: 'explicit rebuild requested'`, and is skipped by the normal
+health-driven pass in the same call — it was already rebuilt unconditionally.
+
+Reach for the explicit door when you need certainty regardless of self-report;
+reach for bare `repairIndex()` for routine maintenance and after any incident
+where you're not sure which family (if any) needs it.
+
+## What `suspect` counts mean
+
+Storage's canonical count ledger increments the ALL-visibility total on every new
+record and decrements it on every *proven* delete — one where the record was read,
+or the caller supplied its prior image. A delete that cannot prove what it removed
+existed doesn't guess: it flags the ledger `suspect` (an operator-visible
+`console.warn`, narrated once per session, not once per delete) rather than risk
+decrementing a total that was never incremented for that record in the first
+place. This is intentionally rare — it's a defensive fallback for callers on an
+unusual removal path, not a per-delete cost.
+
+`suspect` is not directly exposed on any `Brainy` method today — it lives on the
+`StorageAdapter`'s optional `getCanonicalCounts()`, primarily consulted by
+`repairIndex()`'s recount step and by custom storage adapters composing their own
+`healthReport()`. What matters for an application: a `suspect` ledger is not
+incorrect, just *unverified since the last recount* — and `repairIndex()`'s
+unconditional count-rollup step (step 2, above) recomputes the ALL scalars from a
+real canonical walk on every call, clearing the flag with proof either way.
+
+## Practical guidance
+
+- **On a normal restart**, do nothing — `init()` brings every provider to
+  serving before it returns, or fails loudly.
+- **On a `*NotReadyError`** from a live read, reconcile with `repairIndex()`
+  (report-driven is almost always sufficient) and retry.
+- **After an incident** where you distrust a specific family regardless of what
+  it reports healthy — a storage-layer fault, a suspicious restore — use the
+  explicit door: `repairIndex({ rebuild: ['metadata' | 'graph' | 'vector'] })`.
+- **To audit before trusting a report**, `brain.auditGraph()` walks every stored
+  relationship and proves (or disproves) that reads return canonical truth,
+  independent of what any provider self-reports — see
+  [Inspecting a Live Brainy](../guides/inspection.md).

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@soulcraft/brainy",
-  "version": "10.4.0-rc.1",
+  "version": "10.4.0-rc.2",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@soulcraft/brainy",
-      "version": "10.4.0-rc.1",
+      "version": "10.4.0-rc.2",
       "license": "MIT",
       "dependencies": {
         "@msgpack/msgpack": "^3.1.2",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@soulcraft/brainy",
-  "version": "10.4.0-rc.1",
+  "version": "10.4.0-rc.2",
   "description": "Universal Knowledge Protocol™ - World's first Triple Intelligence database unifying vector, graph, and document search in one API. Stage 3 CANONICAL: 42 nouns × 127 verbs covering 96-97% of all human knowledge.",
   "main": "dist/index.js",
   "module": "dist/index.js",

src/index.ts

@@ -269,6 +269,10 @@ export type { FamilyStamp, StampMembers, StampVerdict } from './db/familyStamp.j
 export { isVersionedIndexProvider } from './plugin.js'
 export type { VersionedIndexProvider } from './plugin.js'
 export type { ProviderInvariantReport, InvariantResult, InvariantHeal } from './plugin.js'
+// The named, synchronous, O(1) health-report contract (the read gate's ONLY
+// source of truth for "can I serve right now") — see HealthReport's
+// derivation laws in plugin.ts.
+export type { HealthReport, LedgerInvariantResult, InvariantSource } from './plugin.js'
 // Optional provider self-report of outstanding background maintenance work
 // (compaction, deferred writes, etc.) — the payload type for
 // brain.maintenanceDebt(). See the measure-only-what-you-track contract on
@@ -385,7 +389,10 @@ import type {
   HNSWVerb,
   HNSWConfig,
   StorageAdapter,
-  DerivedFamilyDeclaration
+  DerivedFamilyDeclaration,
+  // The canonical count ledger a storage adapter maintains (counted + ALL-visibility
+  // scalars per family, the coverage-ledger denominators) — see StorageAdapter.getCanonicalCounts.
+  CanonicalCounts
 } from './coreTypes.js'
 
 // Export vector index implementation (the JS HNSW path)

src/plugin.ts

@@ -9,6 +9,7 @@
  * registered manually via `brain.use()` — there is no implicit detection.
  */
 
+import { prodLog } from './utils/logger.js'
 import type {
   StorageAdapter,
   Vector,
@@ -171,6 +172,66 @@ export interface ProviderInvariantReport {
   durationMs: number
 }
 
+/**
+ * @description Where a {@link LedgerInvariantResult} verdict came from:
+ * - `'ledger'`     — decided from an exact, durable ledger (a real count, not a sample).
+ * - `'deep'`       — decided by a full/expensive scan (the `validateInvariants()` diagnostic path only).
+ * - `'unledgered'` — this family has no ledger yet; the verdict is UNKNOWN, never healthy and never broken.
+ */
+export type InvariantSource = 'ledger' | 'deep' | 'unledgered'
+
+/**
+ * @description One invariant verdict inside a {@link HealthReport}. Extends
+ * {@link InvariantResult} with the provenance of the verdict ({@link InvariantSource})
+ * and, for a failing set-membership invariant, an exact count plus a capped sample
+ * of the diverging ids — a VERDICT, never a dump. `sample` MUST be capped at 16 ids;
+ * `count` is the exact number even when `sample` is truncated.
+ */
+export interface LedgerInvariantResult extends InvariantResult {
+  /** Provenance of this verdict — see {@link InvariantSource}. */
+  source: InvariantSource
+  /** Exact count of diverging/missing items plus a capped (≤16 ids) sample. Present only on a failing set-membership invariant. */
+  missing?: { count: number; sample: string[] }
+}
+
+/**
+ * @description The NAMED, SYNCHRONOUS, O(1) health report a provider exposes via
+ * {@link MetadataIndexProvider.healthReport} / {@link GraphIndexProvider.healthReport} /
+ * {@link VectorIndexProvider.healthReport}. This is the read gate's ONLY source of
+ * truth for "can I serve right now" — it replaces sampled self-probes and the
+ * unnamed `isReady()` latch with an exact, ledger-derived verdict.
+ *
+ * Derivation laws (a provider MUST honor these; brainy's read gate assumes them):
+ * - `healthy` = every VERIFIED invariant in {@link invariants} holds. An invariant
+ *   whose family is named in {@link unledgered} is NEVER counted toward `healthy`
+ *   either way — it is unknown, not passing.
+ * - `serving` = no verified invariant in {@link invariants} FAILS with `heal: 'rebuild'`.
+ *   A failure with `heal: 'repair'` or `heal: 'none'` is degraded-but-serving —
+ *   `serving` stays `true`. Only a `'rebuild'`-grade failure makes `serving` `false`.
+ * - `validateInvariants()` remains the async DEEP diagnostic (full scans allowed,
+ *   `source: 'deep'` results); `healthReport()` MUST be synchronous, O(1) from
+ *   exact ledgers/counters, and MUST NOT throw for a well-formed provider — a
+ *   provider that cannot produce a safe verdict reports it as a failing invariant,
+ *   it does not throw (a throw is read by the gate as a CONTRACT VIOLATION, not as
+ *   "unknown").
+ */
+export interface HealthReport extends ProviderInvariantReport {
+  /**
+   * Monotonic per provider: bumps on every ledger mutation and every rebuild
+   * boundary. Consumers (the read gate's narration dedup, external callers) may
+   * cache a verdict per generation.
+   */
+  generation: number
+  /** Each checked invariant, with provenance — see {@link LedgerInvariantResult}. */
+  invariants: LedgerInvariantResult[]
+  /**
+   * Families with no ledger yet. NAMED here so an operator can see what is not
+   * yet tracked — NEVER counted as healthy (they are not verified) and NEVER
+   * counted as broken (there is nothing to fail).
+   */
+  unledgered: string[]
+}
+
 /**
  * @description A provider's self-report of its own outstanding background
  * maintenance work (compaction, deferred writes, a build-new→verify→swap in
@@ -266,6 +327,20 @@ export interface MetadataIndexProvider {
    */
   validateInvariants?(): Promise<ProviderInvariantReport>
 
+  /**
+   * @description OPTIONAL. The named, SYNCHRONOUS, O(1) health verdict this
+   * provider derives from its own exact ledgers — see {@link HealthReport} for
+   * the full derivation laws. MUST NOT perform I/O and MUST NOT throw for a
+   * well-formed provider (brainy treats a throw as a CONTRACT VIOLATION, never
+   * as "unknown"). When present, brainy's read gate (`assessProviderHealth()`)
+   * reads THIS instead of `isReady()` / size heuristics: `serving` decides
+   * whether reads may proceed; a `false` refuses the read loudly rather than
+   * triggering a rebuild. Absent → the gate falls back to `isReady?()` / the
+   * size heuristic (this train's JS built-in providers stay on that interim
+   * path).
+   */
+  healthReport?(): HealthReport
+
   /**
    * @description OPTIONAL. A native provider returns true from the moment its
    * `init()` detects a large epoch-drift until its background
@@ -462,6 +537,20 @@ export interface GraphIndexProvider {
    */
   validateInvariants?(): Promise<ProviderInvariantReport>
 
+  /**
+   * @description OPTIONAL. The named, SYNCHRONOUS, O(1) health verdict this
+   * provider derives from its own exact ledgers — see {@link HealthReport} for
+   * the full derivation laws. MUST NOT perform I/O and MUST NOT throw for a
+   * well-formed provider (brainy treats a throw as a CONTRACT VIOLATION, never
+   * as "unknown"). When present, brainy's read gate (`assessProviderHealth()`)
+   * reads THIS instead of `isReady()` / size heuristics: `serving` decides
+   * whether reads may proceed; a `false` refuses the read loudly rather than
+   * triggering a rebuild. Absent → the gate falls back to `isReady?()` / the
+   * size heuristic (this train's JS built-in providers stay on that interim
+   * path).
+   */
+  healthReport?(): HealthReport
+
   /**
    * @description OPTIONAL eager cold-load. Called once during brain init — AFTER
    * the metadata provider's `init()` (so the id-mapper is hydrated; a native int
@@ -1225,6 +1314,20 @@ export interface VectorIndexProvider {
    */
   validateInvariants?(): Promise<ProviderInvariantReport>
 
+  /**
+   * @description OPTIONAL. The named, SYNCHRONOUS, O(1) health verdict this
+   * provider derives from its own exact ledgers — see {@link HealthReport} for
+   * the full derivation laws. MUST NOT perform I/O and MUST NOT throw for a
+   * well-formed provider (brainy treats a throw as a CONTRACT VIOLATION, never
+   * as "unknown"). When present, brainy's read gate (`assessProviderHealth()`)
+   * reads THIS instead of `isReady()` / size heuristics: `serving` decides
+   * whether reads may proceed; a `false` refuses the read loudly rather than
+   * triggering a rebuild. Absent → the gate falls back to `isReady?()` / the
+   * size heuristic (this train's JS built-in providers stay on that interim
+   * path).
+   */
+  healthReport?(): HealthReport
+
   /**
    * @description OPTIONAL. A native provider returns true from the moment its
    * `init()` detects a large epoch-drift until its background
@@ -1472,9 +1575,13 @@ export class PluginRegistry {
         this.activated.add(name)
         activated.push(name)
       } else {
-        // Documented graceful decline (activate() → false). Surface it loudly so
+        // Documented graceful decline (activate() → false). Surface it on the
-        // a silent degrade to the default engine never goes unnoticed.
+        // ALWAYS-ON channel: `silent: true` patches console, and a declined
-        console.warn(
+        // accelerator warned into a patched console is a silent degrade to the
+        // default engines — the exact invisible-fallback class this registry
+        // exists to prevent (a production storm ran the WASM engine for 90s
+        // behind one suppressed warn).
+        prodLog.warn(
           `[brainy] Plugin "${name}" declined activation (activate() returned false); ` +
             `the default engine is in use for its providers.`
         )

src/storage/storageFactory.ts

@@ -154,6 +154,21 @@ export function resolveFilesystemRoot(
   ) {
     throwRemovedStorageKey('fileSystemStorage.path')
   }
+  // A nested `config` object carrying a path-shaped key is the same hazard in
+  // a shape nobody ever supported: it used to fall through SILENTLY to the
+  // shared default root — every instance writing one directory while its
+  // caller believed each had its own. (Found live: an integration test's
+  // brains shared one store across a whole single-process run and a health
+  // probe refused on the foreign edges it sampled.) Loud, with the rename.
+  const nested = (config as Record<string, unknown>).config
+  if (nested && typeof nested === 'object') {
+    const pathish = ['path', 'baseDir', 'rootDirectory', 'rootDir', 'dir', 'directory']
+    const hit = pathish.find(
+      (k) => typeof (nested as Record<string, unknown>)[k] === 'string' &&
+        ((nested as Record<string, unknown>)[k] as string).length > 0
+    )
+    if (hit) throwRemovedStorageKey(`config.${hit}`)
+  }
 
   // 3. Zero-config default. A `type: 'filesystem'` with no path lands here
   //    intentionally ("persist, default location").

src/types/brainy.types.ts

@@ -1816,10 +1816,16 @@ export interface BrainyConfig {
     | StorageAdapter
 
   /**
-   * Disable the automatic index rebuild check during `init()`. By default
+   * RE-MEANT (the health-gate contract): `init()` (open) always verifies the
-   * Brainy auto-decides from dataset size: small datasets rebuild missing
+   * durable generation of every derived index, and a needed rebuild ALWAYS
-   * indexes inline, large datasets rebuild lazily on first query. Set `true`
+   * runs at open — it is never deferred to the first read, regardless of
-   * only when an operator wants full manual control via `repairIndex()`.
+   * dataset size or this flag. There is no first-query lazy-build path
+   * anymore: a read that finds a provider not serving throws a typed
+   * `*NotReadyError` rather than building anything (see
+   * `assessProviderHealth` / the read gate in `brainy.ts`). Setting this
+   * `true` no longer defers index construction to the first query — it has
+   * no effect on WHEN a needed rebuild runs. Full manual control over
+   * rebuilds remains available via `repairIndex({ rebuild: [...] })`.
    */
   disableAutoRebuild?: boolean
 

src/utils/indexReadiness.ts

@@ -13,13 +13,28 @@
  * `size()` or `isInitialized`. When `isReady()` is absent, callers must fall back
  * to a KNOWN-ITEM PROBE (a real search/lookup that must return a known-present
  * datum) before trusting an empty result — never a `size()` proxy.
+ *
+ * {@link assessProviderHealth} is the NEWER, PREFERRED authority: it reads a
+ * provider's NAMED, synchronous, O(1) {@link import('../plugin.js').HealthReport}
+ * when one is exposed, and falls back to this file's `isReady()` classifier only
+ * when the provider does not (yet) expose a health report. Read paths in
+ * `brainy.ts` call `assessProviderHealth` exclusively — `assessIndexReadiness`
+ * stays exported for the other call sites (`storage/baseStorage.ts`) and for the
+ * fallback branch inside `assessProviderHealth` itself.
  */
 
+import type { HealthReport } from '../plugin.js'
+
 /** A provider that MAY expose the honest cold-load readiness signal. */
 export interface MaybeReadyProvider {
   isReady?: () => boolean
 }
 
+/** A provider that MAY expose the named, synchronous, O(1) health report. */
+export interface MaybeHealthReportingProvider {
+  healthReport?: () => HealthReport
+}
+
 /** Three-valued honest-readiness verdict. */
 export type IndexReadiness = 'ready' | 'not-ready' | 'unknown'
 
@@ -36,3 +51,105 @@ export function assessIndexReadiness(provider: unknown): IndexReadiness {
   if (p == null || typeof p.isReady !== 'function') return 'unknown'
   return p.isReady() ? 'ready' : 'not-ready'
 }
+
+/**
+ * @description Which signal {@link assessProviderHealth} actually consulted to
+ * produce its verdict — surfaced so callers can narrate (and tests can pin) how
+ * a provider was judged, not just what the judgment was.
+ * - `'health-report'`  — the provider's `healthReport()` was called (the authority).
+ * - `'is-ready'`       — no `healthReport()`; fell back to the provider's `isReady()`.
+ * - `'size-heuristic'` — no `healthReport()` and no `isReady()`; caller must keep its own size-based heuristic.
+ * - `'none'`           — there was no provider to assess (`null`/`undefined`).
+ */
+export type ProviderHealthVia = 'health-report' | 'is-ready' | 'size-heuristic' | 'none'
+
+/** The result of {@link assessProviderHealth}. */
+export interface ProviderHealthAssessment {
+  /** The honest readiness verdict — see {@link IndexReadiness}. */
+  readiness: IndexReadiness
+  /** The provider's raw {@link HealthReport}, when one was obtained; `null` otherwise. */
+  report: HealthReport | null
+  /** Which signal produced the verdict — see {@link ProviderHealthVia}. */
+  via: ProviderHealthVia
+  /** Human-readable reasons: named failing invariants (with `heal`), unledgered families, or the fallback-path explanation. Empty when the provider is healthy and ready. */
+  reasons: string[]
+}
+
+/**
+ * @description THE read-gate authority. Prefers a provider's NAMED,
+ * synchronous, O(1) {@link HealthReport} over the older `isReady()` / size
+ * heuristics; falls back to {@link assessIndexReadiness}'s semantics only when
+ * a provider does not (yet) expose `healthReport()`.
+ *
+ * Derivation:
+ * - `healthReport()` present → call it (wrapped in try/catch). A THROW is a
+ *   CONTRACT VIOLATION, not "unknown": returns `readiness: 'not-ready'`,
+ *   `via: 'health-report'`, and a reason naming the throw — never swallowed
+ *   into `'unknown'`.
+ * - Otherwise → `readiness = report.serving ? 'ready' : 'not-ready'`; `reasons`
+ *   names every invariant with `holds: false` (with its `heal`), plus an
+ *   `unledgered: [...]` line when {@link HealthReport.unledgered} is non-empty.
+ *   UNLEDGERED IS UNKNOWN: an unledgered family never flips a serving provider
+ *   to not-ready, and never flips a not-serving provider to ready — `serving`
+ *   is always the provider's own verdict, verbatim.
+ * - No `healthReport()` → fall back to {@link assessIndexReadiness}'s semantics:
+ *   `via: 'is-ready'` when `isReady()` exists, `via: 'size-heuristic'` when
+ *   neither hook exists (caller must keep its own size-based heuristic),
+ *   `via: 'none'` when there is no provider at all.
+ * @param provider - Any index provider (vector / graph / metadata) or `null`/`undefined`.
+ */
+export function assessProviderHealth(provider: unknown): ProviderHealthAssessment {
+  const p = provider as (MaybeHealthReportingProvider & MaybeReadyProvider) | null | undefined
+
+  if (p == null) {
+    return { readiness: 'unknown', report: null, via: 'none', reasons: ['no provider to assess'] }
+  }
+
+  if (typeof p.healthReport === 'function') {
+    let report: HealthReport
+    try {
+      report = p.healthReport()
+    } catch (err) {
+      const message = err instanceof Error ? err.message : String(err)
+      return {
+        readiness: 'not-ready',
+        report: null,
+        via: 'health-report',
+        reasons: [`healthReport() threw: ${message} — a health-report throw is a contract violation, never read as healthy`]
+      }
+    }
+
+    const reasons: string[] = []
+    for (const invariant of report.invariants) {
+      if (!invariant.holds) {
+        reasons.push(`${invariant.name} (heal:${invariant.heal}): ${invariant.detail}`)
+      }
+    }
+    if (report.unledgered.length > 0) {
+      reasons.push(`unledgered: ${report.unledgered.join(', ')}`)
+    }
+
+    return {
+      readiness: report.serving ? 'ready' : 'not-ready',
+      report,
+      via: 'health-report',
+      reasons
+    }
+  }
+
+  const readiness = assessIndexReadiness(p)
+  if (readiness === 'unknown') {
+    return {
+      readiness,
+      report: null,
+      via: 'size-heuristic',
+      reasons: ['provider exposes neither healthReport() nor isReady() — falling back to the size heuristic']
+    }
+  }
+  return {
+    readiness,
+    report: null,
+    via: 'is-ready',
+    reasons: readiness === 'not-ready' ? ['isReady() returned false'] : []
+  }
+}

src/utils/metadataIndex.ts

@@ -20,6 +20,7 @@ import {
   type WatermarkVerdict,
   type WatermarkVerdictResult
 } from './projectionWatermark.js'
+import type { FactScanHandle } from '../db/factLog.js'
 import {
   NounType,
   VerbType,
@@ -77,6 +78,31 @@ export interface MetadataIndexStats {
   indexSize: number // in bytes
 }
 
+/**
+ * @description What {@link MetadataIndexManager.applyWatermarkCatchup} did,
+ * for the caller's narration.
+ * - `'noop'` — the verdict was `null`/`'adopt'`: the artifact already
+ *   reflects committed truth. Zero index writes.
+ * - `'rescan'` — the verdict was `'rescan'`, OR a `'catchup'` verdict was
+ *   demoted (no window, or no fact log to scan) — either way a full
+ *   {@link MetadataIndexManager.rebuild} already ran; `reason` names why.
+ * - `'caught-up'` — the `(from, to]` window folded successfully; the
+ *   artifact is stamped and flushed at `to`.
+ */
+export interface CatchupApplyResult {
+  action: 'noop' | 'rescan' | 'caught-up'
+  /** Present on `'rescan'` — why the fold could not proceed as a catchup. */
+  reason?: string
+  /** Present on `'caught-up'` — the fact-log window that was folded. */
+  window?: { from: number; to: number }
+  /** Present on `'caught-up'` — noun ops applied (add/update/delete). */
+  nounsApplied?: number
+  /** Present on `'caught-up'` — verb ops applied (add/update/delete). */
+  verbsApplied?: number
+  /** Present on `'caught-up'` — distinct committed generations folded. */
+  factsApplied?: number
+}
+
 export interface MetadataIndexConfig {
   maxIndexSize?: number // Max number of entries per field value (default: 10000)
   rebuildThreshold?: number // Rebuild if index is this % stale (default: 0.1)
@@ -147,6 +173,52 @@ export class MetadataIndexManager implements MetadataIndexProvider {
   private stampedWatermark: number | null = null
   /** The three-way verdict computed at init; null until init runs. */
   private loadVerdict: WatermarkVerdictResult | null = null
+  /**
+   * Set only when {@link loadVerdict}.verdict is `'rescan'`: whether a
+   * persisted artifact existed at load (even an unstamped/unverifiable
+   * one) — distinguishes genuine first boot (nothing here yet, routine)
+   * from an artifact whose watermark is unverifiable (the loud case). The
+   * verdict value alone doesn't carry this distinction; see {@link
+   * watermarkArtifactPresent}.
+   */
+  private rescanArtifactPresent = false
+
+  /**
+   * @description THE BUILD-BESIDE SEAM (B3 Deliverable 3): when set (via
+   * {@link beginShadow}), every live `addToIndex`/`removeFromIndex` call on
+   * THIS instance also applies to the shadow instance — so a caller building
+   * a fresh replacement manager beside this one (walking canonical into it)
+   * never misses a write that lands during the build. This is the ONE seam
+   * that makes build-beside possible without touching every call site: every
+   * existing `AddToMetadataIndexOperation`/`RemoveFromMetadataIndexOperation`
+   * (and the JS manager's own `rebuild()`/catchup fold) keep calling the SAME
+   * serving instance exactly as before; only THIS instance knows it is also
+   * mirroring to a shadow. Null = no build in flight (the overwhelmingly
+   * common case; the check costs one property read per write).
+   */
+  private shadow: MetadataIndexManager | null = null
+
+  /**
+   * @description Start mirroring every `addToIndex`/`removeFromIndex` call on
+   * this instance to `shadow` too — see {@link shadow}'s JSDoc. The caller
+   * owns sequencing: writes mirrored WHILE a canonical walk is populating
+   * `shadow` may be clobbered by the walk's own (possibly stale) reads for
+   * the same id; the caller closes that window with a bounded fact-log fold
+   * AFTER the walk (the same mechanism {@link applyWatermarkCatchup} uses)
+   * before treating `shadow` as authoritative.
+   * @param shadow - The manager to mirror writes to.
+   */
+  beginShadow(shadow: MetadataIndexManager): void {
+    this.shadow = shadow
+  }
+
+  /**
+   * @description Stop mirroring writes to a shadow (see {@link beginShadow}).
+   * Idempotent; a no-op when no shadow is attached.
+   */
+  endShadow(): void {
+    this.shadow = null
+  }
 
   // Cardinality and field statistics tracking
   private fieldStats = new Map<string, FieldStats>()
@@ -1604,6 +1676,15 @@ export class MetadataIndexManager implements MetadataIndexProvider {
     for (const { field } of fields) {
       this.metadataCache.invalidatePattern(`field_values_${field}`)
     }
+
+    // THE BUILD-BESIDE SEAM — see `shadow`'s JSDoc. Mirrors this write to a
+    // shadow manager under construction, if one is attached. `skipFlush:
+    // true` always: the shadow's own persistence is the build orchestrator's
+    // job (it flushes once, after the swap — never mid-build, to avoid
+    // colliding with this instance's own persisted keys).
+    if (this.shadow) {
+      await this.shadow.addToIndex(id, entityOrMetadata, true, false, generation)
+    }
   }
 
   /**
@@ -1676,6 +1757,11 @@ export class MetadataIndexManager implements MetadataIndexProvider {
     // the real commit watermark (the JS mapper ignores it).
     this.idMapper.remove(id, generation)
     await this.idMapper.flush()
+
+    // THE BUILD-BESIDE SEAM — see `shadow`'s JSDoc.
+    if (this.shadow) {
+      await this.shadow.removeFromIndex(id, metadata, generation)
+    }
   }
 
   /**
@@ -2759,8 +2845,8 @@ export class MetadataIndexManager implements MetadataIndexProvider {
    * `'adopt'` (stamped == committed, zero work), `'catchup'` (stamped <
    * committed; the gap from {@link watermarkGap} awaits an incremental
    * fold), `'rescan'` (unstamped or stamped above committed — never
-   * trusted). Null until init() has run. Computed and exposed only; no
+   * trusted). Null until init() has run. The coordinator (`Brainy.open()`)
-   * load behavior changes ride on it yet.
+   * consumes this via {@link applyWatermarkCatchup} right after init.
    */
   watermarkVerdict(): WatermarkVerdict | null {
     return this.loadVerdict?.verdict ?? null
@@ -2774,6 +2860,223 @@ export class MetadataIndexManager implements MetadataIndexProvider {
     return this.loadVerdict?.gap ?? null
   }
 
+  /**
+   * @description Meaningful only when {@link watermarkVerdict} is
+   * `'rescan'`: `true` when a persisted artifact existed at load (even an
+   * unstamped/unverifiable one — real prior state, worth narrating loudly);
+   * `false` for a genuine first boot (nothing persisted yet — a caller
+   * should narrate this at a routine log level, not as an alarm, even
+   * though the verdict value is the same `'rescan'` either way).
+   */
+  watermarkArtifactPresent(): boolean {
+    return this.rescanArtifactPresent
+  }
+
+  /**
+   * @description Consume the three-way watermark verdict {@link
+   * watermarkVerdict} computed at init — the cure for a crash-recovered
+   * store whose canonical reads/counts recover every acked write but whose
+   * metadata projection (flushed only periodically, not per-commit) keeps
+   * serving the pre-crash state. Call once, right after `init()`, before
+   * anything reads from this projection.
+   *
+   *  - `null`/`'adopt'` → the artifact already reflects the store's
+   *    committed generation. Zero index writes.
+   *  - `'catchup'` → the caller-supplied `scan` (expected already opened
+   *    over `(watermarkGap().from, watermarkGap().to]`) is folded in, ONE
+   *    op at a time, through the SAME two legs {@link rebuild} uses (ADR-007
+   *    A4 — one mechanism, never a second hand-rolled add/update shape): a
+   *    tombstone (`op.record === null`) retracts id-keyed (this projection
+   *    keeps no per-record delta log, so the pre-crash metadata for that id
+   *    — if any — is what a value-precise removal would need, and it isn't
+   *    available; the same tradeoff `remove()`'s null-metadata closure
+   *    already accepts elsewhere); an after-image retracts-then-reposts, so
+   *    an update never leaves stale postings under the old field values. A
+   *    fact outside the window is skipped defensively (belt: the scan is
+   *    already opened to the window; suspenders: this loop never trusts an
+   *    over-run). On success the artifact is stamped at `to` and flushed —
+   *    the same STAMP-AFTER-DATA door {@link flush} always writes through.
+   *  - `'rescan'` (or a `'catchup'` verdict with no window, or no `scan` to
+   *    fold — the store hosts no fact log) → the persisted artifact is
+   *    unverifiable; this method runs the existing {@link rebuild} itself
+   *    rather than leave the caller to notice and trigger it separately.
+   *
+   * @param scan - An open fact scan covering the catchup window (see
+   *   {@link Brainy.scanFacts}), or `null` when none is available/needed.
+   *   Ignored when the verdict is not `'catchup'`.
+   * @returns What happened — see {@link CatchupApplyResult}.
+   */
+  async applyWatermarkCatchup(scan: FactScanHandle | null): Promise<CatchupApplyResult> {
+    const verdict = this.watermarkVerdict()
+    if (verdict === null || verdict === 'adopt') return { action: 'noop' }
+
+    if (verdict === 'rescan') {
+      await this.rebuild()
+      return {
+        action: 'rescan',
+        reason: 'persisted artifact is unverifiable (unstamped, or stamped ABOVE the ' +
+          "store's committed generation) — never adopting unverifiable state"
+      }
+    }
+
+    // verdict === 'catchup'
+    const window = this.watermarkGap()
+    if (window === null) {
+      await this.rebuild()
+      return { action: 'rescan', reason: "'catchup' verdict exposed no window — cannot bound a fold" }
+    }
+    if (scan === null) {
+      await this.rebuild()
+      return {
+        action: 'rescan',
+        reason: `no fact log available to fold the (${window.from}, ${window.to}] catchup window`
+      }
+    }
+
+    const { nounsApplied, verbsApplied, factsApplied } = await this.foldFactWindow(scan, window.from, window.to)
+
+    this.stampWatermark(window.to)
+    await this.flush()
+    return { action: 'caught-up', window, nounsApplied, verbsApplied, factsApplied }
+  }
+
+  /**
+   * @description Fold an open fact scan's `(fromGeneration, toGeneration]`
+   * window into this projection, ONE op at a time, through the SAME two legs
+   * {@link rebuild} uses (ADR-007 A4 — one mechanism, never a second
+   * hand-rolled add/update shape): a tombstone retracts id-keyed; an
+   * after-image retracts-then-reposts. THE CORE LOOP shared by {@link
+   * applyWatermarkCatchup} (which stamps + flushes after) and {@link
+   * buildBeside} (which does neither — persistence is the caller's job,
+   * exactly once, after a swap). Never stamps, never flushes, never touches
+   * storage beyond what `addToIndex`/`removeFromIndex` do internally
+   * (skipFlush is always forced true).
+   * @param scan - An open fact scan.
+   * @param fromGeneration - Window lower bound (exclusive).
+   * @param toGeneration - Window upper bound (inclusive).
+   * @returns Counts for the caller's narration.
+   */
+  private async foldFactWindow(
+    scan: FactScanHandle,
+    fromGeneration: number,
+    toGeneration: number
+  ): Promise<{ nounsApplied: number; verbsApplied: number; factsApplied: number }> {
+    let nounsApplied = 0
+    let verbsApplied = 0
+    let factsApplied = 0
+    for await (const batch of scan.batches()) {
+      for (const fact of batch.facts) {
+        // Defensive containment: the scan is already opened to the window,
+        // but a fact outside it is never applied regardless.
+        if (fact.generation <= fromGeneration || fact.generation > toGeneration) continue
+        const generation = BigInt(fact.generation)
+        for (const op of fact.ops) {
+          if (op.record === null) {
+            // TOMBSTONE — the id-keyed removal path (no per-record delta
+            // log to recover the old field values from).
+            await this.removeFromIndex(op.id, undefined, generation)
+          } else {
+            // AFTER-IMAGE — retract any stale posting for this id, then
+            // repost the new shape. Covers both a fresh add (nothing to
+            // retract; a no-op-ish remove) and an update, through the same
+            // two calls.
+            await this.removeFromIndex(op.id, undefined, generation)
+            await this.indexStoredRecord(op.id, op.record.metadata, {
+              skipFlush: true,
+              deferWrites: false,
+              generation
+            })
+          }
+          if (op.kind === 'noun') nounsApplied++
+          else verbsApplied++
+        }
+        factsApplied++
+      }
+    }
+    return { nounsApplied, verbsApplied, factsApplied }
+  }
+
+  /**
+   * @description B3 Deliverable 3 — the shadow-build lifecycle's init: the
+   * MINIMUM setup {@link buildBeside} needs, deliberately NOT the general
+   * {@link init} sequence. Two reasons general `init()` is unsafe for a
+   * build-beside shadow:
+   *  1. `init()` unconditionally re-initializes the id mapper from storage
+   *     (`idMapper.init()`) — safe for a FRESH mapper, but this instance is
+   *     constructed with the CURRENTLY-SERVING manager's SHARED, already-live
+   *     mapper (identity is shared, never a second mapper — this train's own
+   *     law). Re-running its init() would DISCARD every not-yet-flushed
+   *     UUID↔int assignment sitting in memory, breaking the live manager's
+   *     own serving mid-build.
+   *  2. `init()` loads the field registry and, on a registry that's
+   *     missing/empty while canonical has entities (exactly the shape a
+   *     rebuild is often invoked to FIX), triggers `rebuild()` itself —
+   *     WITHOUT `inMemoryOnly`, which would touch the shared storage keys
+   *     the live manager depends on.
+   * What this DOES run: the WASM roaring-bitmap library init (idempotent;
+   * needed before any column-store write) and the column store's OWN
+   * segment-manifest discovery (read-only against shared storage; needed so
+   * THIS instance's eventual post-swap flush continues segment numbering
+   * correctly instead of colliding with the retiring manager's segments).
+   */
+  private async initForShadowBuild(): Promise<void> {
+    await roaringLibraryInitialize()
+    try {
+      await this.columnStore.init(this.storage, this.idMapper)
+    } catch (err) {
+      prodLog.warn('[MetadataIndex] shadow build: column store storage discovery failed:', err)
+    }
+  }
+
+  /**
+   * @description B3 Deliverable 3 — THE ONLINE REBUILD's manager-side half:
+   * populate THIS instance (expected fresh/empty, constructed with the SAME
+   * storage + idMapper as the manager it will replace — see {@link
+   * initForShadowBuild}) from canonical storage without ever touching the
+   * shared storage keys the currently-serving manager depends on — no chunk
+   * deletion, no flush, anywhere in this call. The caller (the brain's
+   * rebuild-beside orchestrator) is responsible for:
+   *  1. Attaching this instance as a {@link beginShadow} target on the OLD
+   *     manager BEFORE calling this, so live writes during the walk mirror
+   *     here too (best-effort — the walk below may still clobber a mirrored
+   *     write with a stale read for the same id; the fold after the walk is
+   *     what makes the final state authoritative, not the mirror).
+   *  2. Swapping its own reference to this instance once this resolves.
+   *  3. Calling {@link stampWatermark} + {@link flush} EXACTLY ONCE, after
+   *     the swap — this instance never persists itself.
+   * @param committedGenerationAtStart - The store's committed generation
+   *   captured by the caller BEFORE this call — the fold's lower bound.
+   * @returns The generation this instance's canonical data reflects once the
+   *   walk + fold settle — the fold's upper bound (writes committed after
+   *   this point but before the swap only reach this instance via the live
+   *   {@link beginShadow} mirror, so the caller re-reads the store's
+   *   committed generation right before stamping, rather than trusting this
+   *   return value as final).
+   * @throws If canonical advanced during the walk but no fact log is
+   *   available to fold the gap — never a silently incomplete shadow.
+   */
+  async buildBeside(committedGenerationAtStart: number): Promise<number> {
+    await this.initForShadowBuild()
+    await this.rebuild({ inMemoryOnly: true })
+
+    const committedAfterWalk = this.storage.committedGeneration?.() ?? committedGenerationAtStart
+    if (committedAfterWalk > committedGenerationAtStart) {
+      const scan = this.storage.scanFacts?.({
+        fromGeneration: committedGenerationAtStart + 1,
+        toGeneration: committedAfterWalk
+      }) ?? null
+      if (scan === null) {
+        throw new Error(
+          `MetadataIndexManager.buildBeside: canonical advanced from generation ` +
+            `${committedGenerationAtStart} to ${committedAfterWalk} during the walk, but this ` +
+            `store hosts no fact log to fold the gap — refusing a silently incomplete shadow`
+        )
+      }
+      await this.foldFactWindow(scan, committedGenerationAtStart, committedAfterWalk)
+    }
+    return committedAfterWalk
+  }
+
   /**
    * @description Write the pending watermark stamp as a sidecar record —
    * always called AFTER the data it certifies is durable. A stamp-write
@@ -2826,6 +3129,7 @@ export class MetadataIndexManager implements MetadataIndexProvider {
 
     if (result.verdict === 'rescan') {
       const artifactPresent = this.fieldIndexes.size > 0 || stamped !== null
+      this.rescanArtifactPresent = artifactPresent
       if (artifactPresent) {
         prodLog.warn(
           `[MetadataIndex] watermark verdict: RESCAN — persisted index is ` +
@@ -3484,13 +3788,48 @@ export class MetadataIndexManager implements MetadataIndexProvider {
     }
   }
 
+  /**
+   * @description Index one raw stored noun/verb record — THE ONE add leg
+   * shared by {@link rebuild}'s canonical walk and {@link
+   * applyWatermarkCatchup}'s fact-log fold (ADR-007 A4: one mechanism,
+   * never a second hand-rolled shape). No conversion step is needed here:
+   * a raw stored record (`storage.getNounMetadata`/`getVerbMetadata`, or a
+   * fact's after-image `record.metadata`) is byte-identical — both read the
+   * exact same canonical path — and already the v2 nested-bag
+   * ("entity-record") shape {@link extractIndexableFields} expects.
+   * @param id - Entity/relationship id.
+   * @param storedMetadata - The raw stored metadata record.
+   * @param opts.skipFlush - Forwarded to {@link addToIndex}.
+   * @param opts.deferWrites - Forwarded to {@link addToIndex}.
+   * @param opts.generation - Forwarded to {@link addToIndex}.
+   */
+  private async indexStoredRecord(
+    id: string,
+    storedMetadata: unknown,
+    opts: { skipFlush: boolean; deferWrites: boolean; generation?: bigint }
+  ): Promise<void> {
+    await this.addToIndex(id, storedMetadata, opts.skipFlush, opts.deferWrites, opts.generation)
+  }
+
   /**
    * Rebuild entire index from scratch using pagination
    * Non-blocking version that yields control back to event loop
    * Sparse indices now lazy-loaded via UnifiedCache (no need to clear Map)
+   *
+   * @param options.inMemoryOnly - B3 Deliverable 3 (build-beside): when
+   *   `true`, this call never touches the shared storage keys another,
+   *   currently-serving `MetadataIndexManager` over the SAME storage may
+   *   depend on — it skips deleting persisted legacy chunk files AND skips
+   *   the final `flush()` (which would otherwise write field indexes AND
+   *   flush the column store's tail buffers to shared segment keys,
+   *   colliding with a live manager's own writes). The caller ({@link
+   *   buildBeside}) owns persistence entirely — exactly once, after this
+   *   instance becomes the sole owner via an atomic swap. Default `false`
+   *   (every other caller keeps today's clear-then-persist behavior).
    */
-  async rebuild(): Promise<void> {
+  async rebuild(options?: { inMemoryOnly?: boolean }): Promise<void> {
     if (this.isRebuilding) return
+    const inMemoryOnly = options?.inMemoryOnly ?? false
 
     this.isRebuilding = true
     try {
@@ -3519,15 +3858,22 @@ export class MetadataIndexManager implements MetadataIndexProvider {
       // here — it's always saved at the end of rebuild via flush(). This ensures
       // that if rebuild fails partway, the next init() can still discover fields
       // and trigger another rebuild attempt.
-      prodLog.info('Clearing existing metadata index chunks from storage...')
+      //
-      const existingFields = await this.getPersistedFieldList()
+      // SKIPPED for inMemoryOnly: these are the SHARED storage keys a live
+      // manager over the same storage may still be reading (see this
+      // method's JSDoc) — deleting them before the swap is a live-read
+      // hazard, not a cleanup.
+      if (!inMemoryOnly) {
+        prodLog.info('Clearing existing metadata index chunks from storage...')
+        const existingFields = await this.getPersistedFieldList()
 
-      if (existingFields.length > 0) {
+        if (existingFields.length > 0) {
-        for (const field of existingFields) {
+          for (const field of existingFields) {
-          await this.deleteFieldChunks(field)
+            await this.deleteFieldChunks(field)
+          }
+
+          prodLog.info(`Cleared ${existingFields.length} field indexes from storage`)
         }
-
-        prodLog.info(`Cleared ${existingFields.length} field indexes from storage`)
       }
 
       // EntityIdMapper is intentionally NOT cleared here. Rebuild re-iterates
@@ -3582,7 +3928,7 @@ export class MetadataIndexManager implements MetadataIndexProvider {
         for (const noun of result.items) {
           const metadata = metadataBatch.get(noun.id)
           if (metadata) {
-            await this.addToIndex(noun.id, metadata, true, true)
+            await this.indexStoredRecord(noun.id, metadata, { skipFlush: true, deferWrites: true })
           }
         }
 
@@ -3627,7 +3973,7 @@ export class MetadataIndexManager implements MetadataIndexProvider {
         for (const verb of result.items) {
           const metadata = verbMetadataBatch.get(verb.id)
           if (metadata) {
-            await this.addToIndex(verb.id, metadata, true, true)
+            await this.indexStoredRecord(verb.id, metadata, { skipFlush: true, deferWrites: true })
           }
         }
 
@@ -3637,8 +3983,16 @@ export class MetadataIndexManager implements MetadataIndexProvider {
 
       // Flush to storage. The column store's flush() handles tail-buffer-to-
       // segment promotion + manifest persistence.
-      prodLog.debug('💾 Flushing metadata index to storage...')
+      //
-      await this.flush()
+      // SKIPPED for inMemoryOnly — see this method's JSDoc: flush() writes
+      // the shared field-index keys AND flushes the column store's tail
+      // buffers to shared segment keys, which would race a live manager's
+      // own flushes over the SAME storage. The caller flushes exactly once,
+      // after the swap.
+      if (!inMemoryOnly) {
+        prodLog.debug('💾 Flushing metadata index to storage...')
+        await this.flush()
+      }
 
       prodLog.info(`✅ Metadata index rebuild completed! Processed ${totalNounsProcessed} nouns and ${totalVerbsProcessed} verbs`)
 

tests/configs/vitest.integration.config.ts

@@ -20,6 +20,9 @@ export default defineConfig({
     // Include only integration tests  
     include: [
       'tests/integration/**/*.test.ts',
+      // The lifecycle biography lane (day-in-the-life scenarios; see
+      // tests/lifecycle/README.md) runs in the integration gate.
+      'tests/lifecycle/**/*.test.ts',
       'tests/**/*.integration.test.ts'
     ],
     

tests/integration/batchImportWithRelations.test.ts

@@ -15,13 +15,7 @@ describe('Batch Import with Immediate Relations (v5.7.3 Fix)', () => {
 
     // Initialize brain
     brain = new Brainy({ requireSubtype: false,
-      storage: {
+      storage: { type: 'filesystem', path: testDir },
-        type: 'filesystem',
-        config: {
-          baseDir: testDir,
-          enableCompression: false // Faster tests
-        }
-      },
       dimensions: 384
     })
 

tests/integration/cold-graph-connected-8.0.test.ts

@@ -1,29 +1,29 @@
 /**
  * @module tests/integration/cold-graph-connected-8.0
  * @description BRAINY-COLD-GRAPH-CONNECTED (8.0) — regression coverage for the silent-empty
- * graph-traversal bug, gated on the converged 8.0 contract: a sync `graphIndex.isReady()` that
+ * graph-traversal bug, gated on the honest readiness signal: a sync `graphIndex.isReady()`
- * is true ONLY when the source→target EDGES are loaded (NOT the membership/manifest count).
+ * that is true ONLY when the source→target EDGES are loaded (NOT the membership/manifest count).
  *
- * On the FIRST `find({ connected })` after a cold process start of a LARGE brain (≥10k nouns,
+ * On the FIRST `find({ connected })` after a cold process start, a native graph adjacency can
- * which skips the eager index rebuild), a native graph adjacency can reload its relationship
+ * reload its relationship COUNT (so `size() > 0`) but NOT its edges — so `getNeighbors()` returns
- * COUNT (so `size() > 0`) but NOT its edges — so `getNeighbors()` returns `[]` for EVERY source
+ * `[]` for EVERY source and brainy would serve that `[]` as if the anchor were genuinely edgeless.
- * and brainy would serve that `[]` as if the anchor were genuinely edgeless.
  *
- * The 8.0 guard (`verifyGraphAdjacencyLive`) prefers the honest `isReady()` signal:
+ * RE-POINTED to the health-gate law: `verifyGraphAdjacencyLive` NEVER rebuilds and NEVER walks the
- *  - `isReady() === false` → hydrate the id-mapper, rebuild from storage, re-check; a still-false
+ * store from a read — a read-path rebuild is exactly the dark-rebuild failure mode the law retires
- *    `isReady()` throws {@link GraphIndexNotReadyError} instead of returning `[]` ('rebuilt' when
+ * (open() alone owns building). The guard now:
- *    the rebuild heals it);
+ *  - `isReady() === false` → THROWS {@link GraphIndexNotReadyError} immediately — no rebuild attempt;
  *  - a genuinely edgeless anchor with `isReady() === true` verifies 'live' and the empty result
- *    stands — no spurious rebuild, no throw;
+ *    stands — no spurious throw;
- *  - a provider WITHOUT `isReady()` falls back to the shipped 7.x known-edge-sample probe.
+ *  - a provider WITHOUT `isReady()` falls back to the shipped known-edge-sample probe, which is
+ *    now READ-ONLY: it refuses loudly (throws) rather than self-healing via rebuild.
  *
  * These exercise REAL `find({ connected })` against an in-memory brain whose graph index is
- * instrumented with a test-double `isReady()` (and, for the fallback case, an empty-then-healed
+ * instrumented with a test-double `isReady()` (and, for the fallback case, an always-empty
  * `getNeighbors`). Only the readiness/edge surface is wrapped; the underlying real adjacency
- * (built by `relate()`) is unmasked once a rebuild "heals" it.
+ * (built by `relate()`) is what a healthy provider actually serves.
  */
 
-import { describe, it, expect, afterEach } from 'vitest'
+import { describe, it, expect, afterEach, vi } from 'vitest'
 import { Brainy } from '../../src/index.js'
 import { NounType, VerbType } from '../../src/types/graphTypes.js'
 import { GraphIndexNotReadyError } from '../../src/errors/brainyError.js'
@@ -63,17 +63,17 @@ async function buildBrain(
 }
 
 /**
- * Instrument the brain's real graph index with a test-double `isReady()` (the 8.0 contract) plus
+ * Instrument the brain's real graph index with a test-double `isReady()` (the honest-readiness
- * an edge surface that goes empty while NOT ready. `getNeighbors` returns `[]` while `!ready`
+ * contract) plus an edge surface that goes empty while NOT ready. `getNeighbors` returns `[]`
- * (modelling the cold-unloaded adjacency) and delegates to the REAL index once a rebuild flips
+ * while `!ready` (modelling the cold-unloaded adjacency) and delegates to the REAL index once
- * `ready` on. `rebuild` is counted; it heals (`ready = true`) only when `healsOnRebuild` is set.
+ * `ready` flips true (used only by the "healthy" control cases — the guard itself never flips
- * Pass `failFirstRebuild` to make the FIRST rebuild throw a transient error (without healing) so
+ * this anymore, since it never rebuilds). `rebuild` is counted so tests can assert it is NEVER
- * the empty-result re-collect path in executeGraphSearch is exercised.
+ * called by a read.
  */
 function instrumentIsReady(
   brain: any,
-  opts: { ready: boolean; healsOnRebuild: boolean; failFirstRebuild?: boolean }
+  opts: { ready: boolean }
-): { rebuildCalls: number } {
+): { rebuildCalls: number; ready: boolean } {
   const gi = brain.graphIndex
   const origGetNeighbors = gi.getNeighbors.bind(gi)
   const state = { ready: opts.ready, rebuildCalls: 0 }
@@ -85,10 +85,6 @@ function instrumentIsReady(
 
   gi.rebuild = async (): Promise<void> => {
     state.rebuildCalls++
-    if (opts.failFirstRebuild && state.rebuildCalls === 1) {
-      throw new Error('transient rebuild hiccup')
-    }
-    if (opts.healsOnRebuild) state.ready = true // unmask the real (already-populated) adjacency
   }
 
   return state
@@ -96,12 +92,12 @@ function instrumentIsReady(
 
 /**
  * Fallback instrumentation — a provider WITHOUT `isReady()` (older cortex / JS baseline). Wraps
- * `getNeighbors` to return `[]` while `broken` and delegates to the REAL index once a rebuild
+ * `getNeighbors` to always return `[]` while `broken`. This is the shipped known-edge-sample
- * heals it. This is the shipped 7.x known-edge-sample probe path on 8.0.
+ * probe path — now READ-ONLY: it refuses loudly rather than self-healing.
  */
 function instrumentNoIsReady(
   brain: any,
-  opts: { broken: boolean; healsOnRebuild: boolean }
+  opts: { broken: boolean }
 ): { rebuildCalls: number } {
   const gi = brain.graphIndex
   // Ensure the provider does NOT expose isReady() — the default JS provider doesn't.
@@ -114,13 +110,12 @@ function instrumentNoIsReady(
 
   gi.rebuild = async (): Promise<void> => {
     state.rebuildCalls++
-    if (opts.healsOnRebuild) state.broken = false
   }
 
   return state
 }
 
-describe('BRAINY-COLD-GRAPH-CONNECTED 8.0 — isReady()-gated, never serves a silent []', () => {
+describe('BRAINY-COLD-GRAPH-CONNECTED 8.0 — isReady()-gated, never serves a silent [], never rebuilds from a read', () => {
   let brains: any[] = []
   afterEach(async () => {
     for (const b of brains) {
@@ -131,35 +126,37 @@ describe('BRAINY-COLD-GRAPH-CONNECTED 8.0 — isReady()-gated, never serves a si
       }
     }
     brains = []
+    vi.restoreAllMocks()
   })
 
-  it('(a) isReady() false → rebuild heals it true → find({ connected }) returns correct N (rebuilt)', async () => {
+  it('(a) isReady() false → THROWS GraphIndexNotReadyError immediately, no rebuild attempt', async () => {
-    const { brain, anchorId, targetIds } = await buildBrain({ anchorEdges: true })
-    brains.push(brain)
-    const state = instrumentIsReady(brain, { ready: false, healsOnRebuild: true })
-
-    const results = await brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
-
-    expect(state.rebuildCalls).toBeGreaterThanOrEqual(1) // detected not-ready + healed it
-    const ids = results.map((r: any) => r.id).sort()
-    expect(ids).toEqual(targetIds.sort()) // B, C, D — the real edges, served after the heal
-  })
-
-  it('(b) isReady() stays false after rebuild → throws GraphIndexNotReadyError (NOT a silent [])', async () => {
     const { brain, anchorId } = await buildBrain({ anchorEdges: true })
     brains.push(brain)
-    instrumentIsReady(brain, { ready: false, healsOnRebuild: false }) // rebuild never makes it ready
+    const state = instrumentIsReady(brain, { ready: false })
 
     await expect(
       brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
     ).rejects.toBeInstanceOf(GraphIndexNotReadyError)
+
+    expect(state.rebuildCalls).toBe(0) // a read never rebuilds — it refuses loudly instead
+  })
+
+  it('(b) isReady() stays false → throws GraphIndexNotReadyError (NOT a silent [])', async () => {
+    const { brain, anchorId } = await buildBrain({ anchorEdges: true })
+    brains.push(brain)
+    const state = instrumentIsReady(brain, { ready: false })
+
+    await expect(
+      brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
+    ).rejects.toBeInstanceOf(GraphIndexNotReadyError)
+    expect(state.rebuildCalls).toBe(0)
   })
 
   it('(c) edgeless anchor + isReady() true → returns [] with NO rebuild and NO throw', async () => {
     // The anchor has no edges, but E -> F does — the adjacency is genuinely loaded (ready).
     const { brain, anchorId } = await buildBrain({ anchorEdges: false })
     brains.push(brain)
-    const state = instrumentIsReady(brain, { ready: true, healsOnRebuild: false })
+    const state = instrumentIsReady(brain, { ready: true })
 
     const results = await brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
 
@@ -170,7 +167,7 @@ describe('BRAINY-COLD-GRAPH-CONNECTED 8.0 — isReady()-gated, never serves a si
   it('(d) healthy isReady() true → correct results, NO rebuild', async () => {
     const { brain, anchorId, targetIds } = await buildBrain({ anchorEdges: true })
     brains.push(brain)
-    const state = instrumentIsReady(brain, { ready: true, healsOnRebuild: false })
+    const state = instrumentIsReady(brain, { ready: true })
 
     const results = await brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
 
@@ -179,30 +176,30 @@ describe('BRAINY-COLD-GRAPH-CONNECTED 8.0 — isReady()-gated, never serves a si
     expect(ids).toEqual(targetIds.sort())
   })
 
-  it('(e) provider WITHOUT isReady() → falls back to the known-edge-sample probe (self-heals)', async () => {
+  it('(e) provider WITHOUT isReady() → the known-edge-sample probe REFUSES LOUDLY (never self-heals)', async () => {
-    const { brain, anchorId, targetIds } = await buildBrain({ anchorEdges: true })
+    const { brain, anchorId } = await buildBrain({ anchorEdges: true })
     brains.push(brain)
-    const state = instrumentNoIsReady(brain, { broken: true, healsOnRebuild: true })
+    const state = instrumentNoIsReady(brain, { broken: true })
 
-    const results = await brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
+    await expect(
+      brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
+    ).rejects.toBeInstanceOf(GraphIndexNotReadyError)
 
-    expect(state.rebuildCalls).toBeGreaterThanOrEqual(1) // detected the empty adjacency + healed it
+    expect(state.rebuildCalls).toBe(0) // the fallback probe is READ-ONLY — it never calls rebuild()
-    const ids = results.map((r: any) => r.id).sort()
-    expect(ids).toEqual(targetIds.sort()) // B, C, D — served after the heal
   })
 
-  it('(f) executeGraphSearch re-collect: a transient first rebuild leaves connectedIds empty; the empty-result guard then heals + re-collects', async () => {
+  it('(f) an empty connectedIds set re-verifies against a not-serving adjacency and throws, rather than serving [] as truth', async () => {
-    // First verify (inside neighbors()) hits a transient rebuild failure → returns 'live' without
+    // executeGraphSearch's cold-load guard (connectedIds.size === 0 → re-verify) used to
-    // healing, so getNeighbors stays empty and connectedIds is empty. The empty connectedIds set
+    // interpret a healed rebuild as "re-collect and serve." That rebuild-and-heal path is
-    // then drives executeGraphSearch's own verify, whose rebuild now heals → 'rebuilt' → re-collect.
+    // retired: the re-verify now either confirms a genuinely edgeless anchor ('live', case (c))
-    const { brain, anchorId, targetIds } = await buildBrain({ anchorEdges: true })
+    // or — as here — discovers the adjacency itself is not serving, and throws.
+    const { brain, anchorId } = await buildBrain({ anchorEdges: true })
     brains.push(brain)
-    const state = instrumentIsReady(brain, { ready: false, healsOnRebuild: true, failFirstRebuild: true })
+    const state = instrumentIsReady(brain, { ready: false })
 
-    const results = await brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
+    await expect(
-
+      brain.find({ connected: { from: anchorId, direction: 'out' }, limit: 10 })
-    expect(state.rebuildCalls).toBeGreaterThanOrEqual(2) // first transient, second heals
+    ).rejects.toBeInstanceOf(GraphIndexNotReadyError)
-    const ids = results.map((r: any) => r.id).sort()
+    expect(state.rebuildCalls).toBe(0)
-    expect(ids).toEqual(targetIds.sort()) // re-collected after the heal
   })
 })

tests/integration/health-gate.test.ts

@@ -0,0 +1,352 @@
+/**
+ * @module tests/integration/health-gate
+ * @description Pins for the health-by-accounting read gate: the read gate stops
+ * consulting an unnamed `isReady()` boolean and reads a NAMED, sync, O(1)
+ * {@link HealthReport}; no read path may ever start a store walk; the open path
+ * brings every provider to serving before it returns; an explicit operator door
+ * (`repairIndex({ rebuild: [...] })`) rebuilds a named leg unconditionally.
+ *
+ * Providers here are white-box test doubles: a `healthReport()` (or, for the
+ * interim-path pins, an `isReady()`) function assigned directly onto the LIVE
+ * JS provider object, the same pattern `tests/unit/validate-invariants-delegation.test.ts`
+ * uses for `validateInvariants`. This exercises brainy's real gate/verify code
+ * against a controlled provider self-report — no engine mocks.
+ */
+import { describe, it, expect, afterEach, vi } from 'vitest'
+import { mkdtempSync, rmSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import {
+  Brainy,
+  NounType,
+  VerbType,
+  GraphIndexNotReadyError,
+  MetadataIndexNotReadyError,
+  VectorIndexNotReadyError
+} from '../../src/index.js'
+import type { HealthReport, LedgerInvariantResult } from '../../src/plugin.js'
+import { prodLog } from '../../src/utils/logger.js'
+import { createTestConfig } from '../helpers/test-factory.js'
+
+/** The white-box surface these pins drive on a live brain instance. */
+interface BrainInternals {
+  storage: {
+    getNoun(id: string): Promise<unknown>
+    getNounMetadata(id: string): Promise<unknown>
+    getNouns(options?: unknown): Promise<unknown>
+    getVerbs(options?: unknown): Promise<unknown>
+  }
+  index: { healthReport?: () => HealthReport; isReady?: () => boolean; rebuild(): Promise<void> }
+  metadataIndex: {
+    healthReport?: () => HealthReport
+    isReady?: () => boolean
+    rebuild(): Promise<void>
+    validateInvariants?: () => Promise<unknown>
+  }
+  graphIndex: {
+    healthReport?: () => HealthReport
+    isReady?: () => boolean
+    rebuild(): Promise<void>
+    validateInvariants?: () => Promise<unknown>
+  }
+  rebuildIndexesIfNeeded(force?: boolean): Promise<void>
+}
+
+function internalsOf(brain: Brainy): BrainInternals {
+  return brain as unknown as BrainInternals
+}
+
+function invariant(overrides: Partial<LedgerInvariantResult> = {}): LedgerInvariantResult {
+  return {
+    name: 'manifest-residency',
+    holds: true,
+    detail: 'ok',
+    heal: 'none',
+    source: 'ledger',
+    ...overrides
+  }
+}
+
+function healthReport(overrides: Partial<HealthReport> = {}): HealthReport {
+  return {
+    provider: 'vector',
+    healthy: true,
+    serving: true,
+    invariants: [],
+    checkedAt: Date.now(),
+    durationMs: 1,
+    generation: 1,
+    unledgered: [],
+    ...overrides
+  }
+}
+
+const brains: Brainy[] = []
+const dirs: string[] = []
+afterEach(async () => {
+  for (const b of brains.splice(0)) await b.close().catch(() => {})
+  for (const d of dirs.splice(0)) rmSync(d, { recursive: true, force: true })
+  vi.restoreAllMocks()
+})
+
+describe('health gate (a) — not-serving refuses loudly, ZERO canonical reads during the refusal', () => {
+  it('metadata not-serving: find() throws MetadataIndexNotReadyError naming the failing invariant', async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    await brain.add({ data: 'row', type: NounType.Document, metadata: { team: 'atlas' } })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    internals.metadataIndex.healthReport = () =>
+      healthReport({
+        provider: 'metadata',
+        serving: false,
+        healthy: false,
+        invariants: [invariant({ name: 'posted-count-floor', holds: false, heal: 'rebuild', detail: 'posted 2 < canonical 5' })]
+      })
+
+    const getNounSpy = vi.spyOn(internals.storage, 'getNoun')
+    const getNounMetadataSpy = vi.spyOn(internals.storage, 'getNounMetadata')
+    const getNounsSpy = vi.spyOn(internals.storage, 'getNouns')
+
+    await expect(brain.find({ where: { team: 'atlas' } })).rejects.toBeInstanceOf(MetadataIndexNotReadyError)
+    await expect(brain.find({ where: { team: 'atlas' } })).rejects.toThrow(/posted-count-floor/)
+
+    expect(getNounSpy).not.toHaveBeenCalled()
+    expect(getNounMetadataSpy).not.toHaveBeenCalled()
+    expect(getNounsSpy).not.toHaveBeenCalled()
+
+    delete internals.metadataIndex.healthReport
+  })
+
+  it('graph not-serving: related() throws GraphIndexNotReadyError naming the failing invariant, no canonical reads', async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    const a = await brain.add({ data: 'a', type: NounType.Person })
+    const b = await brain.add({ data: 'b', type: NounType.Person })
+    await brain.relate({ from: a, to: b, type: VerbType.Knows })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    internals.graphIndex.healthReport = () =>
+      healthReport({
+        provider: 'graph',
+        serving: false,
+        healthy: false,
+        invariants: [invariant({ name: 'adjacency-residency', holds: false, heal: 'rebuild', detail: 'edges not loaded' })]
+      })
+
+    const getNounSpy = vi.spyOn(internals.storage, 'getNoun')
+    const getVerbsSpy = vi.spyOn(internals.storage, 'getVerbs')
+
+    await expect(brain.related({ from: a })).rejects.toBeInstanceOf(GraphIndexNotReadyError)
+    await expect(brain.related({ from: a })).rejects.toThrow(/adjacency-residency/)
+
+    expect(getNounSpy).not.toHaveBeenCalled()
+    expect(getVerbsSpy).not.toHaveBeenCalled()
+
+    delete internals.graphIndex.healthReport
+  })
+})
+
+describe('health gate (b) — unledgered is unknown: never blocks a serving provider', () => {
+  it('serving:true with an unledgered family and no failing invariant serves normally; at most one narration', async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    await brain.add({ data: 'row', type: NounType.Document, metadata: { team: 'atlas' } })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    internals.metadataIndex.healthReport = () =>
+      healthReport({
+        provider: 'metadata',
+        serving: true,
+        healthy: true,
+        invariants: [],
+        unledgered: ['canonical-verb-coverage']
+      })
+
+    const warnSpy = vi.spyOn(prodLog, 'warn')
+
+    const r1 = await brain.find({ where: { team: 'atlas' } })
+    const r2 = await brain.find({ where: { team: 'atlas' } })
+    expect(r1.length).toBe(1)
+    expect(r2.length).toBe(1)
+
+    const narrations = warnSpy.mock.calls.filter(
+      ([msg]) => typeof msg === 'string' && msg.includes('canonical-verb-coverage')
+    )
+    expect(narrations.length).toBe(1) // one narration at most across both reads (same generation)
+
+    delete internals.metadataIndex.healthReport
+  })
+})
+
+describe('health gate (c) — degraded-but-serving narrates once per generation', () => {
+  it('a heal:"repair" failure serves; narrates once per generation, twice across a generation bump', async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    await brain.add({ data: 'row', type: NounType.Document, metadata: { team: 'atlas' } })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    let generation = 1
+    internals.index.healthReport = () =>
+      healthReport({
+        provider: 'vector',
+        serving: true,
+        healthy: false,
+        invariants: [invariant({ name: 'stale-vector-counter', holds: false, heal: 'repair', detail: 'counter drift' })],
+        generation
+      })
+
+    const warnSpy = vi.spyOn(prodLog, 'warn')
+    const countNarrations = () =>
+      warnSpy.mock.calls.filter(([msg]) => typeof msg === 'string' && msg.includes('stale-vector-counter')).length
+
+    await expect(brain.find({ where: { team: 'atlas' } })).resolves.toHaveLength(1)
+    await expect(brain.find({ where: { team: 'atlas' } })).resolves.toHaveLength(1)
+    expect(countNarrations()).toBe(1) // same generation both times — one narration
+
+    generation = 2
+    await expect(brain.find({ where: { team: 'atlas' } })).resolves.toHaveLength(1)
+    expect(countNarrations()).toBe(2) // generation bumped — a second narration
+
+    delete internals.index.healthReport
+  })
+})
+
+describe('health gate (d) — interim isReady()-only path (no healthReport) is unchanged', () => {
+  it('isReady() === true serves; isReady() === false refuses via the typed NotReady error', async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    await brain.add({ data: 'row', type: NounType.Document, metadata: { team: 'atlas' } })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    internals.metadataIndex.isReady = () => true
+    await expect(brain.find({ where: { team: 'atlas' } })).resolves.toHaveLength(1)
+
+    internals.metadataIndex.isReady = () => false
+    await expect(brain.find({ where: { team: 'atlas' } })).rejects.toBeInstanceOf(MetadataIndexNotReadyError)
+
+    delete internals.metadataIndex.isReady
+  })
+})
+
+describe('health gate (e) — open builds; the first read never does', () => {
+  it('disableAutoRebuild:true on a populated store: open narrates + builds; the first find() triggers zero rebuilds', async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'brainy-healthgate-open-'))
+    dirs.push(dir)
+
+    const writer = new Brainy({
+      storage: { type: 'filesystem', path: dir },
+      requireSubtype: false,
+      silent: true,
+      disableAutoRebuild: true
+    })
+    await writer.init()
+    brains.push(writer)
+    await writer.add({ data: 'row one', type: NounType.Document, metadata: { team: 'atlas' } })
+    await writer.flush()
+    await brains.pop()!.close()
+
+    const warnSpy = vi.spyOn(prodLog, 'warn')
+    const reader = new Brainy({
+      storage: { type: 'filesystem', path: dir },
+      requireSubtype: false,
+      silent: true,
+      disableAutoRebuild: true
+    })
+    const internals = internalsOf(reader)
+    const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded')
+
+    await reader.init()
+    brains.push(reader)
+
+    expect(rebuildSpy).toHaveBeenCalledTimes(1) // open() built it, exactly once
+    expect(
+      warnSpy.mock.calls.some(
+        ([msg]) => typeof msg === 'string' && msg.includes('open() is building')
+      )
+    ).toBe(true)
+
+    rebuildSpy.mockClear()
+    const rows = await reader.find({ where: { team: 'atlas' } })
+    expect(rebuildSpy).toHaveBeenCalledTimes(0) // the read never builds
+    expect(rows.length).toBe(1)
+  }, 30000)
+})
+
+describe('health gate (f) — the ceremony door: explicit rebuild bypasses invariant consultation', () => {
+  it("repairIndex({ rebuild: ['graph'] }) rebuilds unconditionally without consulting validateInvariants", async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    await brain.add({ data: 'x', type: NounType.Concept })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    let validateCalls = 0
+    internals.graphIndex.validateInvariants = async () => {
+      validateCalls++
+      return healthReport({ provider: 'graph' })
+    }
+    const rebuildSpy = vi.spyOn(internals.graphIndex, 'rebuild')
+
+    const report = await brain.repairIndex({ rebuild: ['graph'] })
+
+    expect(rebuildSpy).toHaveBeenCalledTimes(1)
+    expect(validateCalls).toBe(0) // the door never consults validateInvariants to decide
+
+    const graphFamily = report.families.find((f) => f.family === 'provider:graph')
+    expect(graphFamily?.rebuilt).toBe(true)
+    expect(graphFamily?.checked).toBe(true)
+    expect(graphFamily?.reason).toBe('explicit rebuild requested')
+
+    delete internals.graphIndex.validateInvariants
+  })
+
+  it('bare repairIndex() on a healthy provider calls no rebuild()', async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    await brain.add({ data: 'x', type: NounType.Concept })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    internals.graphIndex.validateInvariants = async () => healthReport({ provider: 'graph', healthy: true, serving: true })
+    const rebuildSpy = vi.spyOn(internals.graphIndex, 'rebuild')
+
+    await brain.repairIndex()
+
+    expect(rebuildSpy).not.toHaveBeenCalled()
+
+    delete internals.graphIndex.validateInvariants
+  })
+})
+
+describe('health gate (g) — a throwing healthReport() is a contract violation, never read as healthy', () => {
+  it('healthReport() that throws refuses loudly with the typed NotReady error naming the throw', async () => {
+    const brain = new Brainy(createTestConfig({ silent: true }))
+    await brain.init()
+    brains.push(brain)
+    await brain.add({ data: 'row', type: NounType.Document, metadata: { team: 'atlas' } })
+    await brain.flush()
+
+    const internals = internalsOf(brain)
+    internals.index.healthReport = () => {
+      throw new Error('accelerator: mmap window busy')
+    }
+
+    await expect(brain.find({ where: { team: 'atlas' } })).rejects.toBeInstanceOf(VectorIndexNotReadyError)
+    await expect(brain.find({ where: { team: 'atlas' } })).rejects.toThrow(/mmap window busy/)
+
+    delete internals.index.healthReport
+  })
+})

tests/integration/metadata-online-rebuild.test.ts

@@ -0,0 +1,167 @@
+/**
+ * @module tests/integration/metadata-online-rebuild
+ * @description THE ONLINE JS METADATA REBUILD (B3 Deliverable 3) pins.
+ * `MetadataIndexManager.rebuild()` used to be clear-then-walk — reads went
+ * dark for the duration. `repairIndex({ rebuild: ['metadata'] })` now builds
+ * a fresh replacement index BESIDE the live one (walk canonical + mirror
+ * every live write via `beginShadow`/`endShadow` + a bounded fact-log fold),
+ * then atomically swaps the brain's reference — `find()` never observes a
+ * half-built index, and a write landing DURING the build is never lost.
+ */
+process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
+
+import { describe, it, expect, afterEach } from 'vitest'
+import { mkdtempSync, rmSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { Brainy } from '../../src/brainy.js'
+import { NounType, VerbType } from '../../src/types/graphTypes.js'
+import type { MetadataIndexManager } from '../../src/utils/metadataIndex.js'
+
+const dirs: string[] = []
+const brains: Brainy<any>[] = []
+afterEach(async () => {
+  for (const b of brains.splice(0)) await b.close().catch(() => {})
+  for (const d of dirs.splice(0)) rmSync(d, { recursive: true, force: true })
+})
+
+function metadataIndexOf(brain: Brainy<any>): MetadataIndexManager {
+  return (brain as unknown as { metadataIndex: MetadataIndexManager }).metadataIndex
+}
+
+async function openBrain(): Promise<{ brain: Brainy<any>; dir: string }> {
+  const dir = mkdtempSync(join(tmpdir(), 'brainy-online-rebuild-'))
+  dirs.push(dir)
+  const brain = new Brainy<any>({
+    requireSubtype: false,
+    storage: { type: 'filesystem', path: dir },
+    silent: true,
+    persistence: { policy: 'manual' },
+    logAuthority: 'adopt'
+  })
+  await brain.init()
+  brains.push(brain)
+  return { brain, dir }
+}
+
+describe('repairIndex({ rebuild: ["metadata"] }) — the online build-beside rebuild', () => {
+  it(
+    'a find() polled throughout the rebuild of a 2k-noun store never returns fewer rows than ' +
+      'before the build started, and a write landing DURING the build is never lost',
+    async () => {
+      const { brain, dir } = await openBrain()
+      void dir
+
+      const N = 2000
+      const ids: string[] = []
+      for (let i = 0; i < N; i++) {
+        ids.push(
+          await brain.add({
+            data: `entity ${i}`,
+            type: NounType.Person,
+            metadata: { status: i % 2 === 0 ? 'active' : 'inactive' }
+          })
+        )
+      }
+      for (let i = 0; i < 20; i++) {
+        await brain.relate({
+          from: ids[i], to: ids[i + 1], type: VerbType.WorksWith, metadata: { tag: 'orig' }
+        })
+      }
+      await brain.flush()
+
+      const baseline = await brain.find({ where: { status: 'active' }, limit: 10000 })
+      expect(baseline.length).toBe(N / 2)
+
+      // Kick off the online rebuild WITHOUT awaiting — poll reads and
+      // perform a live write concurrently with it.
+      const repairPromise = brain.repairIndex({ rebuild: ['metadata'] })
+
+      let minObserved = Infinity
+      let polls = 0
+      const pollPromise = (async () => {
+        // Poll until the rebuild settles — bounded so a slow CI box can't
+        // spin forever, generous enough to actually overlap the walk.
+        while (polls < 200) {
+          const rows = await brain.find({ where: { status: 'active' }, limit: 10000 })
+          minObserved = Math.min(minObserved, rows.length)
+          polls++
+          await new Promise((resolve) => setTimeout(resolve, 1))
+        }
+      })()
+
+      const newId = await brain.add({
+        data: 'added during the rebuild',
+        type: NounType.Person,
+        metadata: { status: 'active' }
+      })
+      const newRelId = await brain.relate({
+        from: newId, to: ids[0], type: VerbType.WorksWith, metadata: { tag: 'during-build' }
+      })
+
+      const [report] = await Promise.all([repairPromise, pollPromise])
+
+      // THE PIN: never fewer rows than the pre-build baseline, at any polled
+      // instant — reads served the OLD (fully-populated) manager throughout.
+      expect(polls).toBeGreaterThan(0)
+      expect(minObserved).toBeGreaterThanOrEqual(baseline.length)
+
+      // The repair report still accounts for the family (same receipt shape
+      // regardless of which rebuild mechanism actually ran underneath).
+      const metadataFamily = report.families.find((f) => f.family === 'provider:metadata')
+      expect(metadataFamily?.checked).toBe(true)
+      expect(metadataFamily?.rebuilt).toBe(true)
+
+      // Post-swap correctness: the live write during the build was never
+      // lost (the beginShadow mirror + post-walk fold caught it).
+      const afterActive = await brain.find({ where: { status: 'active' }, limit: 10000 })
+      expect(afterActive.length).toBe(baseline.length + 1)
+      expect(afterActive.some((r) => r.id === newId)).toBe(true)
+
+      const index = metadataIndexOf(brain)
+      expect(await index.getIds('tag', 'during-build')).toEqual([newRelId])
+      expect((await index.getIds('tag', 'orig')).length).toBe(20)
+
+      // The swap stamped the watermark — a reopen adopts, zero rebuild.
+      await brain.close()
+      brains.length = 0 // already closed above; afterEach must not double-close
+      const reopened = new Brainy<any>({
+        requireSubtype: false,
+        storage: { type: 'filesystem', path: dir },
+        silent: true,
+        persistence: { policy: 'manual' },
+        logAuthority: 'adopt'
+      })
+      await reopened.init()
+      brains.push(reopened)
+      const reopenedIndex = metadataIndexOf(reopened)
+      expect(reopenedIndex.watermarkVerdict()).toBe('adopt')
+      const reopenedActive = await reopened.find({ where: { status: 'active' }, limit: 10000 })
+      expect(reopenedActive.length).toBe(afterActive.length)
+    },
+    60000
+  )
+
+  it('repairIndex({ rebuild: ["metadata"] }) on an empty store is a trivial no-op walk', async () => {
+    const { brain } = await openBrain()
+    const report = await brain.repairIndex({ rebuild: ['metadata'] })
+    const metadataFamily = report.families.find((f) => f.family === 'provider:metadata')
+    expect(metadataFamily?.checked).toBe(true)
+    expect(await brain.getNounCount()).toBe(0)
+  })
+
+  it('two consecutive online rebuilds both leave the index correct (idempotent)', async () => {
+    const { brain } = await openBrain()
+    const a = await brain.add({ data: 'a', type: NounType.Person, metadata: { status: 'active' } })
+    await brain.add({ data: 'b', type: NounType.Person, metadata: { status: 'inactive' } })
+    await brain.flush()
+
+    await brain.repairIndex({ rebuild: ['metadata'] })
+    const first = await brain.find({ where: { status: 'active' } })
+    expect(first.map((r) => r.id)).toEqual([a])
+
+    await brain.repairIndex({ rebuild: ['metadata'] })
+    const second = await brain.find({ where: { status: 'active' } })
+    expect(second.map((r) => r.id)).toEqual([a])
+  })
+})

tests/integration/readAfterWrite.test.ts

@@ -34,13 +34,7 @@ describe('Read-After-Write Consistency (v5.7.2 Bug Fix)', () => {
     testDir = join(tmpdir(), `brainy-consistency-${Date.now()}-${Math.random().toString(36).substring(7)}`)
 
     brain = new Brainy({ requireSubtype: false,
-      storage: {
+      storage: { type: 'filesystem', path: testDir },
-        type: 'filesystem',
-        config: {
-          baseDir: testDir,
-          enableCompression: false // Faster tests
-        }
-      },
       dimensions: 384
     })
 

tests/integration/repair-report.test.ts

@@ -68,4 +68,46 @@ describe('repairIndex per-family receipt', () => {
     expect(orphans!.healed, 'the ghost was pruned and receipted').toBeGreaterThan(0)
     expect(report.healedTotal).toBeGreaterThan(0)
   }, 120000)
+
+
+  it("a heal:'repair' verdict routes to the provider's own repair(), and the re-read decides", async () => {
+    // A fake provider report: one failing invariant asking for the INCREMENTAL
+    // heal. repairIndex must call repair() (never rebuild()) and count the heal
+    // only when the post-repair re-read clears the same verdict.
+    const dir = mkdtempSync(join(tmpdir(), 'brainy-repair-route-'))
+    const brain: any = new Brainy({ storage: { type: 'filesystem', path: dir }, requireSubtype: false, silent: true })
+    await brain.init()
+    brains.push(brain)
+    let repairCalls = 0
+    let rebuildCalls = 0
+    let healed = false
+    const failing = {
+      provider: 'vector', healthy: false, serving: true,
+      invariants: [{ name: 'node-coverage', holds: false, detail: 'short 3', heal: 'repair' as const }],
+      checkedAt: 1, durationMs: 1
+    }
+    const clean = {
+      provider: 'vector', healthy: true, serving: true,
+      invariants: [{ name: 'node-coverage', holds: true, detail: 'ok', heal: 'none' as const }],
+      checkedAt: 2, durationMs: 1
+    }
+    ;(brain.index as any).validateInvariants = async () => (healed ? clean : failing)
+    ;(brain.index as any).repair = async () => { repairCalls++; healed = true; return { repaired: 3 } }
+    const origRebuild = (brain.index as any).rebuild
+    ;(brain.index as any).rebuild = async () => { rebuildCalls++ }
+    try {
+      const report = await brain.repairIndex()
+      const row = report.families.find((f: any) => f.family === 'provider:vector')
+      expect(row, 'the provider family is in the receipt').toBeDefined()
+      expect(repairCalls, 'repair() ran exactly once').toBe(1)
+      expect(rebuildCalls, "a heal:'repair' verdict never runs rebuild()").toBe(0)
+      expect(row!.healed, 'the cleared verdict counts as healed').toBe(1)
+      expect(String(row!.detail)).toMatch(/incremental repair cleared: node-coverage/)
+    } finally {
+      delete (brain.index as any).validateInvariants
+      delete (brain.index as any).repair
+      ;(brain.index as any).rebuild = origRebuild
+    }
+  })
+
 })

tests/integration/verb-metadata-rows.test.ts

@@ -0,0 +1,190 @@
+/**
+ * @module tests/integration/verb-metadata-rows
+ * @description THE LIVE VERB PATH pins. Before this train, verb rows entered
+ * the metadata index ONLY via `MetadataIndexManager.rebuild()`'s canonical
+ * walk — every relate()/unrelate()/updateRelation() call, and every
+ * remove()-cascaded relationship, left the metadata index blind to verb
+ * writes until the next rebuild. This file pins that `relate()`,
+ * `unrelate()`, `updateRelation()`, `remove()`'s cascade, and their
+ * `transact()` mirrors now post/retract the SAME verb rows a rebuild would
+ * derive from canonical (ADR-007 A4: one mechanism for add/update, live and
+ * rebuilt).
+ */
+process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
+
+import { describe, it, expect, beforeEach, afterEach } from 'vitest'
+import { Brainy } from '../../src/brainy.js'
+import { NounType, VerbType } from '../../src/types/graphTypes.js'
+import type { MetadataIndexManager } from '../../src/utils/metadataIndex.js'
+
+/** The JS metadata-index manager backing a memory-storage brain in these
+ *  tests (feature-detected in production code via `instanceof
+ *  MetadataIndexManager`; a narrow test-only reach-in here, matching the
+ *  existing idiom in tests/integration/find-where-zero.test.ts and
+ *  tests/integration/level-field-shadow.test.ts). */
+function metadataIndexOf(brain: Brainy<any>): MetadataIndexManager {
+  return (brain as unknown as { metadataIndex: MetadataIndexManager }).metadataIndex
+}
+
+describe('verb metadata rows — the live path matches the rebuild walk', () => {
+  let brain: Brainy<any>
+
+  beforeEach(async () => {
+    brain = new Brainy({ requireSubtype: false, storage: { type: 'memory' }, silent: true })
+    await brain.init()
+  })
+
+  afterEach(async () => {
+    await brain.close()
+  })
+
+  async function addPerson(label: string): Promise<string> {
+    return brain.add({
+      data: `person ${label}`,
+      type: NounType.Person,
+      metadata: { label }
+    })
+  }
+
+  it('(a) relate() posts a metadata-index-backed verb row a query can find', async () => {
+    const a = await addPerson('a')
+    const b = await addPerson('b')
+    const relId = await brain.relate({
+      from: a, to: b, type: VerbType.WorksWith, metadata: { role: 'lead' }
+    })
+
+    // Read it back the SAME way a rebuild-sourced row is queried — the
+    // manager's own posting lookup, keyed on the custom field the caller wrote.
+    const index = metadataIndexOf(brain)
+    expect(await index.getIds('role', 'lead')).toEqual([relId])
+  })
+
+  it('(b) unrelate() retracts the row', async () => {
+    const a = await addPerson('a')
+    const b = await addPerson('b')
+    const relId = await brain.relate({
+      from: a, to: b, type: VerbType.WorksWith, metadata: { role: 'lead' }
+    })
+
+    const index = metadataIndexOf(brain)
+    expect(await index.getIds('role', 'lead')).toEqual([relId])
+
+    // Flush BEFORE retracting the field's only occurrence: this durably
+    // persists the 'role' column (a segment on disk/in the store), so the
+    // post-retraction query below reads "this field exists, zero live
+    // postings" (→ []) rather than "this field has never been written"
+    // (→ FIELD_NOT_INDEXED) — an orthogonal column-store characteristic
+    // (an unflushed field with its last live posting removed reverts to
+    // unknown), not a D2 behavior.
+    await brain.flush()
+
+    await brain.unrelate(relId)
+
+    expect(await index.getIds('role', 'lead')).toEqual([])
+  })
+
+  it('(c) updateRelation({ metadata }) leaves exactly the new values', async () => {
+    const a = await addPerson('a')
+    const b = await addPerson('b')
+    const relId = await brain.relate({
+      from: a, to: b, type: VerbType.WorksWith, metadata: { role: 'lead', team: 'core' }
+    })
+
+    const index = metadataIndexOf(brain)
+    expect(await index.getIds('role', 'lead')).toEqual([relId])
+
+    // Flush first — see (b)'s note: 'role'/'team' must be durably known
+    // fields before their only value is retracted, or the post-update
+    // "gone" checks below throw FIELD_NOT_INDEXED instead of returning [].
+    await brain.flush()
+
+    await brain.updateRelation({ id: relId, metadata: { role: 'reviewer' }, merge: false })
+
+    // Stale values gone (the old shape AND the merge:false-dropped field)…
+    expect(await index.getIds('role', 'lead')).toEqual([])
+    expect(await index.getIds('team', 'core')).toEqual([])
+    // …only the new value serves.
+    expect(await index.getIds('role', 'reviewer')).toEqual([relId])
+  })
+
+  it("(d) remove(entity) cascade retracts every incident relation's metadata row", async () => {
+    const a = await addPerson('a')
+    const b = await addPerson('b')
+    const c = await addPerson('c')
+    const rel1 = await brain.relate({
+      from: a, to: b, type: VerbType.WorksWith, metadata: { tag: 'cascade-test' }
+    })
+    const rel2 = await brain.relate({
+      from: c, to: a, type: VerbType.WorksWith, metadata: { tag: 'cascade-test' }
+    })
+
+    const index = metadataIndexOf(brain)
+    expect((await index.getIds('tag', 'cascade-test')).sort()).toEqual([rel1, rel2].sort())
+
+    // Flush first — see (b)'s note.
+    await brain.flush()
+
+    await brain.remove(a) // a is source of rel1, target of rel2 — both cascade
+
+    expect(await index.getIds('tag', 'cascade-test')).toEqual([])
+  })
+
+  it('(e) a rebuild() reproduces exactly the verb-row population the live path built', async () => {
+    const a = await addPerson('a')
+    const b = await addPerson('b')
+    const c = await addPerson('c')
+    await brain.relate({ from: a, to: b, type: VerbType.WorksWith, metadata: { tag: 'parity', label: 'ab' } })
+    await brain.relate({ from: b, to: c, type: VerbType.RelatedTo, metadata: { tag: 'parity', label: 'bc' } })
+    const relId3 = await brain.relate({
+      from: c, to: a, type: VerbType.WorksWith, metadata: { tag: 'parity', label: 'ca' }
+    })
+    await brain.unrelate(relId3) // exercise retraction too — the rebuild must NOT resurrect it
+
+    const index = metadataIndexOf(brain)
+    const beforeIds = (await index.getIds('tag', 'parity')).slice().sort()
+    expect(beforeIds.length).toBe(2)
+    const beforeAb = await index.getIds('label', 'ab')
+    const beforeBc = await index.getIds('label', 'bc')
+
+    await index.rebuild()
+
+    const afterIds = (await index.getIds('tag', 'parity')).slice().sort()
+    expect(afterIds).toEqual(beforeIds)
+    expect(await index.getIds('label', 'ab')).toEqual(beforeAb)
+    expect(await index.getIds('label', 'bc')).toEqual(beforeBc)
+    expect(await index.getIds('label', 'ca')).toEqual([]) // the unrelated edge stays gone
+  })
+
+  it('(f) transact() relate/unrelate posts/retracts the same metadata-index rows as single-op', async () => {
+    const a = await addPerson('a')
+    const b = await addPerson('b')
+    const c = await addPerson('c')
+    const d = await addPerson('d')
+
+    // Single-op baseline.
+    const singleOpId = await brain.relate({
+      from: a, to: b, type: VerbType.WorksWith, metadata: { tag: 'parity-f' }
+    })
+
+    // transact() mirror.
+    const relateDb = await brain.transact([
+      { op: 'relate', from: c, to: d, type: VerbType.WorksWith, metadata: { tag: 'parity-f' } }
+    ])
+    const transactId = relateDb.receipt!.ids[0]
+    await relateDb.release()
+
+    const index = metadataIndexOf(brain)
+    expect((await index.getIds('tag', 'parity-f')).sort()).toEqual([singleOpId, transactId].sort())
+
+    // Flush first — see (b)'s note: 'tag' must be durably known before its
+    // last live posting is retracted below.
+    await brain.flush()
+
+    // Retract both ways — single-op unrelate() and transact() unrelate.
+    await brain.unrelate(singleOpId)
+    const unrelateDb = await brain.transact([{ op: 'unrelate', id: transactId }])
+    await unrelateDb.release()
+
+    expect(await index.getIds('tag', 'parity-f')).toEqual([])
+  })
+})

tests/lifecycle/README.md

@@ -0,0 +1,22 @@
+# The Lifecycle Lane
+
+One brain, driven through founding, a working day, a clean restart, a
+crash, a repair, and a second life, checked chapter by chapter against an
+independent shadow-model referee (`biographyHarness.ts`). It catches
+COMPOSITION regressions unit tests miss — a store fine in one process but
+broken across a restart/crash/repair. Runs on the plain JS engine, so it
+gates every commit.
+
+Run it: `npx vitest run tests/lifecycle --pool=forks`
+
+A red names the chapter label, the id, and expected-vs-actual — diagnosable
+from the message alone. `biography.test.ts` is split into two `it` blocks
+(Ch1-3, then Ch4-6) purely for reporting; it is still ONE fixed-order story.
+Chapters must never be reordered, skipped, or made conditional, and a
+failing chapter's assertion must never be weakened to force green.
+
+Lab notes (hard-won, keep):
+- `git reset --hard` does NOT remove untracked files — a "clean" tree can still
+  carry stray test stores; use `git clean -fd tests/lifecycle-tmp` equivalents.
+- `silent: true` patches `console` process-wide — never assert narration through
+  `console` spies in this lane; the engine's always-on channel is `prodLog`.

tests/lifecycle/biography.test.ts

@@ -0,0 +1,404 @@
+/**
+ * @module tests/lifecycle/biography
+ * @description THE LIFECYCLE LANE — see `tests/lifecycle/README.md` for what
+ * this proves and how to run it. One scenario, "the working store": a single
+ * brain driven through founding, a working day, a clean restart, a crash, a
+ * repair, and a second life, verified chapter by chapter against an
+ * independent shadow-model referee (`biographyHarness.ts`).
+ *
+ * Split into two `it` blocks so a currently-failing later chapter (see the
+ * second block's header comment — a live engine finding, not a defect in
+ * this lane) never hides the earlier chapters' passing coverage. The two
+ * blocks share one brain's directory and one shadow model, run in the SAME
+ * fixed order the single scenario always has (`describe.sequential` below
+ * exists to say so explicitly, though vitest's own default is sequential
+ * within a file) — this is a split for REPORTING clarity, not a reordering
+ * or conditional skip of any chapter.
+ */
+import { describe, it, expect } from 'vitest'
+import * as fs from 'node:fs'
+import { NounType, VerbType } from '../../src/types/graphTypes.js'
+import type { Brainy } from '../../src/brainy.js'
+import type { AddParams, RelateParams, UpdateParams, UpdateRelationParams } from '../../src/index.js'
+import { abandonAsCrashed, makeTempDir, openBrain, uid } from '../helpers/durabilityKillMatrix.js'
+import {
+  createModel,
+  getCanonicalCountsFor,
+  modelAdd,
+  modelDelete,
+  modelRelate,
+  modelUpdate,
+  modelUpdateRelation,
+  recordVfsFileWrite,
+  snapshotVfsBaseline,
+  verifyChapter,
+  type HubCheck,
+  type ShadowModel
+} from './biographyHarness.js'
+
+const STATUSES = ['active', 'pending', 'closed', 'archived'] as const
+
+/** Cycle a status value to the next one in the fixed rotation — used so
+ * Ch2's 40 updates provably MOVE entities across find() buckets rather than
+ * risking a no-op reassignment of the same value. */
+function nextStatus(current: unknown): (typeof STATUSES)[number] {
+  const currentStr = typeof current === 'string' ? current : STATUSES[0]
+  const idx = STATUSES.indexOf(currentStr as (typeof STATUSES)[number])
+  return STATUSES[(idx < 0 ? 0 : idx + 1) % STATUSES.length]
+}
+
+// ---------------------------------------------------------------------------
+// Shared biography state — set up by the first `it`, consumed by the second.
+// The two blocks are one continuous story told in two named pieces; nothing
+// here resets or diverges between them.
+// ---------------------------------------------------------------------------
+let dir: string
+let model: ShadowModel
+let brain: Brainy
+let hubs: HubCheck[]
+let employees: string[]
+let customers: string[]
+let invoices: string[]
+let tasks: string[]
+let projects: string[]
+let nonHub: string[]
+
+// ---- Wrappers: every call to the real brain updates the shadow model in
+// the same statement, so the two can never drift apart by construction.
+// Defined once, closing over the `let` bindings above so both `it` blocks
+// (and any future reopen inside them) operate on the current brain/model.
+async function doAdd(label: string, params: Omit<AddParams, 'id'>): Promise<string> {
+  const id = uid(label)
+  await brain.add({ ...params, id })
+  modelAdd(model, id, {
+    type: params.type,
+    subtype: params.subtype,
+    metadata: params.metadata ?? {},
+    visibility: params.visibility
+  })
+  return id
+}
+
+async function doUpdate(id: string, patch: Omit<UpdateParams, 'id'>): Promise<void> {
+  await brain.update({ ...patch, id })
+  modelUpdate(model, id, { metadata: patch.metadata, merge: patch.merge, visibility: patch.visibility })
+}
+
+async function doRemove(id: string): Promise<void> {
+  await brain.remove(id)
+  modelDelete(model, id)
+}
+
+async function doRelate(params: RelateParams): Promise<string> {
+  const id = await brain.relate(params)
+  modelRelate(model, id, {
+    from: params.from,
+    to: params.to,
+    type: params.type,
+    subtype: params.subtype,
+    metadata: params.metadata
+  })
+  return id
+}
+
+async function doUpdateRelation(id: string, patch: Omit<UpdateRelationParams, 'id'>): Promise<void> {
+  await brain.updateRelation({ ...patch, id })
+  modelUpdateRelation(model, id, { metadata: patch.metadata, merge: patch.merge })
+}
+
+async function doVfsWrite(path: string, content: string): Promise<void> {
+  await brain.vfs.writeFile(path, content)
+  recordVfsFileWrite(model)
+}
+
+describe.sequential('lifecycle — the working store', () => {
+  it(
+    'Ch1 FOUNDING -> Ch2 A WORKING DAY -> Ch3 CLEAN RESTART: every read serves truth',
+    async () => {
+      process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
+      dir = makeTempDir()
+      model = createModel()
+
+      // logAuthority: 'adopt' from the first open, mirrored across every
+      // reopen — see write-flow-production-shape.test.ts, which the later
+      // crash chapter's at-ack law is pinned against.
+      brain = await openBrain(dir, { logAuthority: 'adopt' })
+
+      // =================================================================
+      // CHAPTER 1 — FOUNDING
+      // =================================================================
+      // Baseline MUST be snapshotted before any biography act — it is the
+      // VFS root's own system-tier footprint, measured, never hardcoded.
+      await snapshotVfsBaseline(brain, model)
+
+      employees = []
+      for (let i = 0; i < 20; i++) {
+        employees.push(
+          await doAdd(`emp-${i}`, {
+            data: `employee record ${i}`,
+            type: NounType.Person,
+            subtype: 'employee',
+            metadata: { status: STATUSES[i % STATUSES.length], department: ['engineering', 'sales', 'support'][i % 3] }
+          })
+        )
+      }
+      customers = []
+      for (let i = 0; i < 20; i++) {
+        customers.push(
+          await doAdd(`cust-${i}`, {
+            data: `customer record ${i}`,
+            type: NounType.Person,
+            subtype: 'customer',
+            metadata: { status: STATUSES[i % STATUSES.length], tier: i % 2 === 0 ? 'gold' : 'standard' }
+          })
+        )
+      }
+      invoices = []
+      for (let i = 0; i < 30; i++) {
+        invoices.push(
+          await doAdd(`inv-${i}`, {
+            data: `invoice record ${i}`,
+            type: NounType.Document,
+            subtype: 'invoice',
+            metadata: { status: STATUSES[i % STATUSES.length], amount: 100 + i * 17 }
+          })
+        )
+      }
+      tasks = []
+      for (let i = 0; i < 25; i++) {
+        tasks.push(
+          await doAdd(`task-${i}`, {
+            data: `task record ${i}`,
+            type: NounType.Task,
+            subtype: 'milestone',
+            metadata: { status: STATUSES[i % STATUSES.length], priority: (i % 5) + 1 }
+          })
+        )
+      }
+      projects = []
+      for (let i = 0; i < 25; i++) {
+        projects.push(
+          await doAdd(`proj-${i}`, {
+            data: `project record ${i}`,
+            type: NounType.Project,
+            metadata: { status: STATUSES[i % STATUSES.length], budget: 1000 * (i + 1) }
+          })
+        )
+      }
+      expect(employees.length + customers.length + invoices.length + tasks.length + projects.length).toBe(120)
+
+      // Five hubs (proj-0..proj-4) fan out to tasks (Contains) and employees
+      // (WorksWith); a residual band of invoice->customer RelatedTo edges is
+      // unrelated to any hub. Hubs are never touched again for the rest of
+      // the biography, so they stay valid adjacency samples in every chapter.
+      const hubIds = projects.slice(0, 5)
+      for (let h = 0; h < 5; h++) {
+        for (let k = 0; k < 15; k++) {
+          const taskIdx = (h * 5 + k) % tasks.length
+          await doRelate({ from: hubIds[h], to: tasks[taskIdx], type: VerbType.Contains, subtype: 'delivers' })
+        }
+        for (let k = 0; k < 10; k++) {
+          const empIdx = (h * 4 + k) % employees.length
+          await doRelate({ from: hubIds[h], to: employees[empIdx], type: VerbType.WorksWith })
+        }
+      }
+      for (let j = 0; j < 25; j++) {
+        await doRelate({ from: invoices[j], to: customers[j % customers.length], type: VerbType.RelatedTo, subtype: 'billed-to' })
+      }
+      expect(model.relations.size).toBe(150)
+
+      // A handful of VFS files.
+      for (let i = 0; i < 5; i++) {
+        await doVfsWrite(`/report-${i}.txt`, `founding report ${i}`)
+      }
+
+      await brain.flush()
+
+      hubs = hubIds.map((id) => ({ id, typeFilters: [VerbType.Contains, VerbType.WorksWith] }))
+      await verifyChapter(brain, model, 'Ch1 FOUNDING', { hubs, bucketField: 'status' })
+
+      // =================================================================
+      // CHAPTER 2 — A WORKING DAY
+      // =================================================================
+      // Non-hub pool for every mutation below.
+      nonHub = [...employees, ...customers, ...invoices, ...tasks, ...projects.slice(5)]
+
+      // 40 updates that provably MOVE entities across find() status buckets.
+      const updateTargets = nonHub.slice(0, 40)
+      for (const id of updateTargets) {
+        const current = model.entities.get(id)!.metadata.status
+        await doUpdate(id, { metadata: { status: nextStatus(current) } })
+      }
+
+      // 10 visibility flips (public -> internal).
+      const visibilityTargets = nonHub.slice(40, 50)
+      for (const id of visibilityTargets) {
+        await doUpdate(id, { visibility: 'internal' })
+      }
+
+      // 15 deletes — some hub members (their edges cascade away), 3 of them
+      // earmarked for Ch6's resurrection.
+      const resurrectIds = [tasks[0], tasks[1], employees[0]]
+      const otherDeletes = [
+        tasks[2], tasks[3], tasks[4], tasks[5], tasks[6],
+        employees[1], employees[2], employees[3],
+        customers[0], customers[1], customers[2], customers[3]
+      ]
+      const ch2DeleteTargets = [...resurrectIds, ...otherDeletes]
+      expect(ch2DeleteTargets.length).toBe(15)
+      for (const id of ch2DeleteTargets) {
+        await doRemove(id)
+      }
+
+      // 20 new adds.
+      const ch2NewTypes = [NounType.Person, NounType.Document, NounType.Task]
+      for (let i = 0; i < 20; i++) {
+        await doAdd(`ch2-new-${i}`, {
+          data: `working-day addition ${i}`,
+          type: ch2NewTypes[i % ch2NewTypes.length],
+          subtype: 'ad-hoc',
+          metadata: { status: STATUSES[i % STATUSES.length] }
+        })
+      }
+
+      // 10 updateRelation metadata patches — read AFTER the deletes above,
+      // so only relations the cascade left alive are ever targeted.
+      const survivingRelationIds = [...model.relations.keys()].slice(0, 10)
+      expect(survivingRelationIds.length).toBe(10)
+      for (const relId of survivingRelationIds) {
+        await doUpdateRelation(relId, { metadata: { reviewed: true } })
+      }
+
+      await brain.flush()
+      await verifyChapter(brain, model, 'Ch2 A WORKING DAY', { hubs, bucketField: 'status' })
+
+      // =================================================================
+      // CHAPTER 3 — CLEAN RESTART
+      // =================================================================
+      await brain.close()
+      brain = await openBrain(dir, { logAuthority: 'adopt' })
+      await verifyChapter(brain, model, 'Ch3 CLEAN RESTART', { hubs, bucketField: 'status' })
+
+      // Leave the brain closed and the directory intact for the next `it`
+      // (the biography continues there) — do NOT remove `dir` here.
+      await brain.close()
+    },
+    300000
+  )
+
+  it(
+    'Ch4 CRASH -> Ch5 REPAIR -> Ch6 SECOND LIFE: continues the Ch3 store',
+    async () => {
+      try {
+        brain = await openBrain(dir, { logAuthority: 'adopt' })
+
+        // ===============================================================
+        // CHAPTER 4 — CRASH
+        // ===============================================================
+        const ch4Types = [NounType.Person, NounType.Document, NounType.Task, NounType.Project]
+        for (let i = 0; i < 10; i++) {
+          await doAdd(`ch4-new-${i}`, {
+            data: `crash-window addition ${i}`,
+            type: ch4Types[i % ch4Types.length],
+            metadata: { status: STATUSES[i % STATUSES.length] }
+          })
+        }
+        const ch4UpdateTargets = nonHub.slice(50, 55) // invoices[10..14] — untouched so far
+        for (const id of ch4UpdateTargets) {
+          await doUpdate(id, { metadata: { status: 'active' } })
+        }
+        // NO flush — abandon exactly the way process death would (the
+        // at-ack law: every write already awaited above must survive).
+        await abandonAsCrashed(brain)
+        brain = await openBrain(dir, { logAuthority: 'adopt' })
+        await verifyChapter(brain, model, 'Ch4 CRASH', { hubs, bucketField: 'status' })
+
+        // ===============================================================
+        // CHAPTER 5 — REPAIR
+        // ===============================================================
+        const report = await brain.repairIndex()
+        for (const family of report.families) {
+          const accounted =
+            family.checked === true || (family.checked === false && typeof family.skipped === 'string' && family.skipped.length > 0)
+          expect(
+            accounted,
+            `[Ch5 REPAIR] family '${family.family}' must be checked or explicitly skipped with a reason; got ${JSON.stringify(family)}`
+          ).toBe(true)
+        }
+        // A healthy store: repair must change nothing the model doesn't
+        // already expect — verifyChapter against the UNCHANGED model proves it.
+        await verifyChapter(brain, model, 'Ch5 REPAIR', { hubs, bucketField: 'status' })
+
+        // ===============================================================
+        // CHAPTER 6 — SECOND LIFE
+        // ===============================================================
+        const ch6Types = [NounType.Person, NounType.Document, NounType.Task, NounType.Project]
+        for (let i = 0; i < 10; i++) {
+          await doAdd(`ch6-new-${i}`, {
+            data: `second-life addition ${i}`,
+            type: ch6Types[i % ch6Types.length],
+            metadata: { status: STATUSES[i % STATUSES.length] }
+          })
+        }
+        const ch6UpdateTargets = nonHub.slice(55, 65) // invoices[15..24] — untouched so far
+        expect(ch6UpdateTargets.every((id) => model.entities.get(id)!.alive)).toBe(true)
+        for (const id of ch6UpdateTargets) {
+          await doUpdate(id, { metadata: { status: 'closed' } })
+        }
+        const ch6DeleteTargets = nonHub
+          .slice(65, 90) // invoices[25..29] + tasks[0..19] (some already dead — filtered below)
+          .filter((id) => model.entities.get(id)!.alive)
+          .slice(0, 7)
+        expect(ch6DeleteTargets.length).toBe(7)
+        for (const id of ch6DeleteTargets) {
+          await doRemove(id)
+        }
+
+        // Resurrection: the SAME three ids Ch2 deleted, reinserted with
+        // BRAND-NEW metadata — the model expects the new metadata only.
+        await doAdd('task-0', { data: 'resurrected task 0', type: NounType.Task, subtype: 'milestone', metadata: { status: 'active', resurrected: true } })
+        await doAdd('task-1', { data: 'resurrected task 1', type: NounType.Task, subtype: 'milestone', metadata: { status: 'pending', resurrected: true } })
+        await doAdd('emp-0', { data: 'resurrected employee 0', type: NounType.Person, subtype: 'employee', metadata: { status: 'active', resurrected: true } })
+        expect(tasks[0]).toBe(uid('task-0')) // same id as Ch1/Ch2 — the resurrection-adjacent shape
+
+        await brain.close()
+        brain = await openBrain(dir, { logAuthority: 'adopt' })
+        await verifyChapter(brain, model, 'Ch6 SECOND LIFE', { hubs, bucketField: 'status' })
+
+        // Final, standalone getCanonicalCounts() exactness check (beyond
+        // verifyChapter's own (f) leg) — the whole ledger, in one shot.
+        const finalCounts = await getCanonicalCountsFor(brain)
+        const aliveEntities = [...model.entities.values()].filter((e) => e.alive)
+        const alivePublicEntities = aliveEntities.filter((e) => (e.visibility ?? 'public') === 'public')
+        const aliveVerbs = model.relations.size
+        expect(finalCounts, 'final getCanonicalCounts() exactness — Ch6 SECOND LIFE').toEqual({
+          nouns: {
+            counted: alivePublicEntities.length + model.vfsFileNouns,
+            all: aliveEntities.length + model.vfsFileNouns + model.vfsBaselineNouns
+          },
+          verbs: {
+            counted: aliveVerbs + model.vfsContainsVerbs,
+            all: aliveVerbs + model.vfsContainsVerbs + model.vfsBaselineVerbs
+          },
+          suspect: false
+        })
+      } finally {
+        await brain.close().catch(() => {})
+        // Best-effort, retried: a still-draining background persistence
+        // write (e.g. count/index write-through) can race a single rmSync
+        // and leave a partial directory behind — retry a couple of times
+        // rather than let this temp dir leak.
+        for (let attempt = 0; attempt < 3; attempt++) {
+          try {
+            fs.rmSync(dir, { recursive: true, force: true })
+            if (!fs.existsSync(dir)) break
+          } catch {
+            // ignore and retry
+          }
+          await new Promise((resolve) => setTimeout(resolve, 100))
+        }
+      }
+    },
+    300000
+  )
+})

tests/lifecycle/biographyHarness.ts

@@ -0,0 +1,389 @@
+/**
+ * @module tests/lifecycle/biographyHarness
+ * @description The referee for the LIFECYCLE LANE (see `biography.test.ts`):
+ * a plain in-memory SHADOW MODEL of a brain's contents, updated by every act
+ * the biography performs (add/update/remove/relate/updateRelation/vfs writes),
+ * plus `verifyChapter()`, which asserts the live brain agrees with the model
+ * after every chapter. No engine code runs inside the model — it is an
+ * independent ledger, not a mirror of the implementation under test.
+ *
+ * COUNT SEMANTICS this harness encodes (verified against the live engine,
+ * not assumed — see the module-level comments below for how each was
+ * confirmed):
+ *
+ * - `getNounCount()` / `getVerbCount()` count PUBLIC-tier alive records only
+ *   (visibility absent or `'public'`) — `'internal'` and `'system'` are both
+ *   excluded. `storage.getCanonicalCounts()` mirrors that same PUBLIC-only
+ *   scalar as `counted`, and additionally reports `all` — every tier,
+ *   unfiltered — as the coverage-ledger denominator (see
+ *   tests/integration/canonical-count-ledger.test.ts).
+ * - `brain.vfs.writeFile()` for a brand-new file at a path directly under the
+ *   VFS root creates exactly ONE new File noun plus ONE new `Contains` verb
+ *   (root -> file), and BOTH are ordinary PUBLIC records (no visibility
+ *   field is set) — so they count toward `getNounCount()`/`getVerbCount()`
+ *   as well as the canonical `all` scalars. Only the VFS ROOT entity itself
+ *   is `'system'`-tier (created once, at `init()`, before any biography
+ *   chapter runs) — that lone record is the only hidden-tier footprint the
+ *   model does not construct explicitly, so it is captured empirically via
+ *   `snapshotVfsBaseline()` immediately after `init()` rather than hardcoded.
+ * - `related()` filters edges by the RELATION's own visibility tier, not by
+ *   the visibility of the entities the edge connects — flipping an entity to
+ *   `'internal'` does not hide its edges from `related()`. This lane never
+ *   sets relation visibility, so every relation the model tracks is exactly
+ *   as reachable as its presence in `model.relations` implies.
+ * - `remove()` cascades: every relation touching the removed entity (as
+ *   `from` or `to`) is hard-deleted along with it. The model mirrors this by
+ *   deleting the relation entirely from `model.relations` (no relation
+ *   "alive" flag — presence in the map IS aliveness).
+ */
+import { expect } from 'vitest'
+import type { Brainy } from '../../src/brainy.js'
+import type { NounType, VerbType } from '../../src/types/graphTypes.js'
+import type { EntityVisibility, StorageAdapter } from '../../src/coreTypes.js'
+
+/**
+ * One entity's complete lifecycle-relevant state, as the biography's acts
+ * leave it. `alive: false` means the model believes the id has been removed
+ * — the entry is KEPT (never deleted from the map) so `verifyChapter` can
+ * assert the negative half of the contract: a dead id must read as `null`.
+ */
+export interface ShadowEntity {
+  type: NounType
+  subtype?: string
+  metadata: Record<string, unknown>
+  visibility?: EntityVisibility
+  alive: boolean
+}
+
+/**
+ * One relation's complete lifecycle-relevant state. There is no `alive`
+ * flag here — presence in {@link ShadowModel.relations} IS aliveness,
+ * mirroring the engine's hard delete of the canonical verb record on
+ * cascade (see the module header).
+ */
+export interface ShadowRelation {
+  from: string
+  to: string
+  type: VerbType
+  subtype?: string
+  metadata: Record<string, unknown>
+}
+
+/**
+ * The independent truth ledger the biography updates on every act it
+ * performs. `verifyChapter` checks the live brain against this — never the
+ * other way around.
+ */
+export interface ShadowModel {
+  entities: Map<string, ShadowEntity>
+  relations: Map<string, ShadowRelation>
+  /**
+   * `getCanonicalCounts()` nouns.all / verbs.all captured right after
+   * `init()`, before chapter 1 — the VFS root's own system-tier footprint.
+   * Set once via {@link snapshotVfsBaseline}; never hardcoded.
+   */
+  vfsBaselineNouns: number
+  vfsBaselineVerbs: number
+  /**
+   * Public nouns/verbs created by `vfs.writeFile()` for a brand-new file at
+   * a flat top-level path: exactly one File noun + one Contains verb per
+   * call (see the module header). Bumped by {@link recordVfsFileWrite}.
+   */
+  vfsFileNouns: number
+  vfsContainsVerbs: number
+}
+
+/** A fresh, empty shadow model — call once before chapter 1. */
+export function createModel(): ShadowModel {
+  return {
+    entities: new Map(),
+    relations: new Map(),
+    vfsBaselineNouns: 0,
+    vfsBaselineVerbs: 0,
+    vfsFileNouns: 0,
+    vfsContainsVerbs: 0
+  }
+}
+
+/** Narrow, documented private-storage access (the same style already used by
+ * `tests/helpers/durabilityKillMatrix.ts`'s `storeOf()`), needed because
+ * `getCanonicalCounts()` lives on the storage adapter, not on `Brainy`. */
+function storageOf(brain: Brainy): StorageAdapter {
+  return (brain as unknown as { storage: StorageAdapter }).storage
+}
+
+/** Public wrapper around the private-storage `getCanonicalCounts()` read, so
+ * callers never need their own private-access cast — used internally by
+ * {@link snapshotVfsBaseline} and {@link verifyChapter}, and by
+ * `biography.test.ts` for its final standalone exactness check. */
+export async function getCanonicalCountsFor(brain: Brainy): ReturnType<NonNullable<StorageAdapter['getCanonicalCounts']>> {
+  const storage = storageOf(brain)
+  if (!storage.getCanonicalCounts) {
+    throw new Error(
+      'lifecycle lane: the storage adapter under test has no getCanonicalCounts() — the canonical-count-exactness leg of this lane is unrepresentable without it.'
+    )
+  }
+  return storage.getCanonicalCounts()
+}
+
+/**
+ * Snapshot the VFS root's own hidden-tier footprint. Call exactly once,
+ * immediately after `init()` and before chapter 1 does anything — this is
+ * the ONE baseline offset the model does not construct by hand (see the
+ * module header for why: the root is `'system'`-tier plumbing the biography
+ * never explicitly creates).
+ */
+export async function snapshotVfsBaseline(brain: Brainy, model: ShadowModel): Promise<void> {
+  const counts = await getCanonicalCountsFor(brain)
+  model.vfsBaselineNouns = counts.nouns.all
+  model.vfsBaselineVerbs = counts.verbs.all
+}
+
+/**
+ * Record one `brain.vfs.writeFile()` call for a brand-new file at a flat
+ * top-level path (no intermediate directories). Bumps both the noun and verb
+ * VFS counters by one, matching the engine's actual write path exactly (see
+ * the module header) — never call this for an overwrite of an existing path,
+ * a nested path (which would also vivify intermediate directory nouns/edges,
+ * a different, unmodeled shape), or the biography loses its exactness.
+ */
+export function recordVfsFileWrite(model: ShadowModel): void {
+  model.vfsFileNouns += 1
+  model.vfsContainsVerbs += 1
+}
+
+/** Record a fresh `add()` (or a Ch6 resurrection — `Map.set` fully replaces
+ * whatever a prior dead entry held, which is exactly the "new metadata only"
+ * contract a resurrection must honor). */
+export function modelAdd(
+  model: ShadowModel,
+  id: string,
+  entity: { type: NounType; subtype?: string; metadata: Record<string, unknown>; visibility?: EntityVisibility }
+): void {
+  model.entities.set(id, {
+    type: entity.type,
+    subtype: entity.subtype,
+    metadata: { ...entity.metadata },
+    visibility: entity.visibility,
+    alive: true
+  })
+}
+
+/** Record an `update()` — merges metadata by default, matching the engine's
+ * `merge: true` default; pass `merge: false` to mirror a full replace. */
+export function modelUpdate(
+  model: ShadowModel,
+  id: string,
+  patch: { metadata?: Record<string, unknown>; merge?: boolean; visibility?: EntityVisibility }
+): void {
+  const existing = model.entities.get(id)
+  if (!existing || !existing.alive) {
+    throw new Error(`shadow model: update() targeted ${id}, which the model does not have alive — biography sequencing bug`)
+  }
+  if (patch.metadata) {
+    existing.metadata = patch.merge === false ? { ...patch.metadata } : { ...existing.metadata, ...patch.metadata }
+  }
+  if (patch.visibility !== undefined) {
+    existing.visibility = patch.visibility
+  }
+}
+
+/** Record a `remove()` — marks the entity dead (entry retained, per
+ * {@link ShadowEntity}) and cascades: every relation touching it, in either
+ * direction, is hard-deleted from the model too (matching the engine). */
+export function modelDelete(model: ShadowModel, id: string): void {
+  const existing = model.entities.get(id)
+  if (!existing || !existing.alive) {
+    throw new Error(`shadow model: remove() targeted ${id}, which the model does not have alive — biography sequencing bug`)
+  }
+  existing.alive = false
+  for (const [relId, rel] of model.relations) {
+    if (rel.from === id || rel.to === id) model.relations.delete(relId)
+  }
+}
+
+/** Record a `relate()` — `id` is the relation id the real call returned. */
+export function modelRelate(
+  model: ShadowModel,
+  id: string,
+  relation: { from: string; to: string; type: VerbType; subtype?: string; metadata?: Record<string, unknown> }
+): void {
+  model.relations.set(id, {
+    from: relation.from,
+    to: relation.to,
+    type: relation.type,
+    subtype: relation.subtype,
+    metadata: { ...(relation.metadata ?? {}) }
+  })
+}
+
+/** Record an `updateRelation()` metadata patch — merges by default. */
+export function modelUpdateRelation(
+  model: ShadowModel,
+  id: string,
+  patch: { metadata?: Record<string, unknown>; merge?: boolean }
+): void {
+  const existing = model.relations.get(id)
+  if (!existing) {
+    throw new Error(`shadow model: updateRelation() targeted ${id}, which the model does not have — biography sequencing bug`)
+  }
+  if (patch.metadata) {
+    existing.metadata = patch.merge === false ? { ...patch.metadata } : { ...existing.metadata, ...patch.metadata }
+  }
+}
+
+/** Order-independent structural equality for plain JSON-shaped metadata. */
+function deepEqual(a: unknown, b: unknown): boolean {
+  if (a === b) return true
+  if (typeof a !== typeof b) return false
+  if (a === null || b === null) return a === b
+  if (typeof a !== 'object') return false
+  const aKeys = Object.keys(a as Record<string, unknown>)
+  const bKeys = Object.keys(b as Record<string, unknown>)
+  if (aKeys.length !== bKeys.length) return false
+  for (const k of aKeys) {
+    if (!deepEqual((a as Record<string, unknown>)[k], (b as Record<string, unknown>)[k])) return false
+  }
+  return true
+}
+
+/** One hub entity to sample for the `related()` adjacency check, plus the
+ * verb type(s) it is known (by biography construction) to have OUT-edges
+ * of, so the type-filtered variant is exercised too. */
+export interface HubCheck {
+  id: string
+  typeFilters: VerbType[]
+}
+
+/** Options steering one `verifyChapter()` call. */
+export interface VerifyOptions {
+  /** Hub entities to sample for the `related()` adjacency check. */
+  hubs: HubCheck[]
+  /** The metadata field `find()` bucket-checks against (a bare string field
+   * every alive entity may or may not carry — distinct values present among
+   * ALIVE model entities are discovered automatically each call, so a
+   * chapter that moves entities across buckets is re-checked exactly). */
+  bucketField: string
+}
+
+/**
+ * Assert the live brain agrees with the model, in full, after one chapter.
+ * Every failure message names the chapter `label`, the id (where
+ * applicable), and expected-vs-actual — a red here must be diagnosable from
+ * the assertion message alone, with no need to re-read this file.
+ */
+export async function verifyChapter(brain: Brainy, model: ShadowModel, label: string, opts: VerifyOptions): Promise<void> {
+  // (a) + (b): every alive entity reads back exactly as modeled; every dead
+  // entity reads as null.
+  for (const [id, entity] of model.entities) {
+    const live = await brain.get(id)
+    if (entity.alive) {
+      expect(live, `[${label}] alive entity ${id} (type=${entity.type}) must be readable via get(), got null`).not.toBeNull()
+      const e = live!
+      expect(e.type, `[${label}] entity ${id} .type mismatch: expected ${entity.type}, got ${e.type}`).toBe(entity.type)
+      expect(e.subtype, `[${label}] entity ${id} .subtype mismatch: expected ${JSON.stringify(entity.subtype)}, got ${JSON.stringify(e.subtype)}`).toBe(entity.subtype)
+      expect(
+        e.visibility,
+        `[${label}] entity ${id} .visibility mismatch: expected ${JSON.stringify(entity.visibility)}, got ${JSON.stringify(e.visibility)}`
+      ).toBe(entity.visibility)
+      const metaMatches = deepEqual(e.metadata ?? {}, entity.metadata)
+      expect(
+        metaMatches,
+        `[${label}] entity ${id} .metadata mismatch: expected ${JSON.stringify(entity.metadata)}, got ${JSON.stringify(e.metadata)}`
+      ).toBe(true)
+    } else {
+      expect(live, `[${label}] dead entity ${id} (type=${entity.type}) must read as null, got ${JSON.stringify(live)}`).toBeNull()
+    }
+  }
+
+  // (c) find({ where: { <bucketField>: value } }) returns exactly the
+  // model's matching alive set, per distinct value currently present.
+  const bucketValues = new Set<string>()
+  for (const entity of model.entities.values()) {
+    if (!entity.alive) continue
+    const v = entity.metadata[opts.bucketField]
+    if (typeof v === 'string') bucketValues.add(v)
+  }
+  for (const value of bucketValues) {
+    const expectedIds = [...model.entities.entries()]
+      .filter(([, e]) => e.alive && e.metadata[opts.bucketField] === value)
+      .map(([id]) => id)
+      .sort()
+    const results = await brain.find({
+      where: { [opts.bucketField]: value } as Record<string, unknown>,
+      includeInternal: true,
+      limit: 100000
+    })
+    const actualIds = results.map((r) => r.id).sort()
+    expect(
+      actualIds,
+      `[${label}] find({ where: { ${opts.bucketField}: ${JSON.stringify(value)} } }) mismatch: expected ${expectedIds.length} ids ${JSON.stringify(expectedIds)}, got ${actualIds.length} ids ${JSON.stringify(actualIds)}`
+    ).toEqual(expectedIds)
+  }
+
+  // (d) related(id) / related(id, { type }) for the hub sample matches the
+  // model's adjacency exactly (out-edges — related(id) is shorthand for
+  // { from: id }).
+  for (const hub of opts.hubs) {
+    const expectedAll = [...model.relations.entries()]
+      .filter(([, r]) => r.from === hub.id)
+      .map(([id]) => id)
+      .sort()
+    const liveAll = await brain.related({ from: hub.id, limit: 100000 })
+    const actualAllIds = liveAll.map((r) => r.id).sort()
+    expect(
+      actualAllIds,
+      `[${label}] related(${hub.id}) mismatch: expected ${expectedAll.length} ids ${JSON.stringify(expectedAll)}, got ${actualAllIds.length} ids ${JSON.stringify(actualAllIds)}`
+    ).toEqual(expectedAll)
+
+    for (const typeFilter of hub.typeFilters) {
+      const expectedTyped = [...model.relations.entries()]
+        .filter(([, r]) => r.from === hub.id && r.type === typeFilter)
+        .map(([id]) => id)
+        .sort()
+      const liveTyped = await brain.related({ from: hub.id, type: typeFilter, limit: 100000 })
+      const actualTypedIds = liveTyped.map((r) => r.id).sort()
+      expect(
+        actualTypedIds,
+        `[${label}] related(${hub.id}, { type: '${typeFilter}' }) mismatch: expected ${expectedTyped.length} ids ${JSON.stringify(expectedTyped)}, got ${actualTypedIds.length} ids ${JSON.stringify(actualTypedIds)}`
+      ).toEqual(expectedTyped)
+    }
+  }
+
+  // (e) getNounCount() / getVerbCount(): PUBLIC-tier alive records
+  // (visibility absent/'public'; 'internal' and 'system' both excluded — see
+  // the module header) plus the VFS's own public contributions.
+  const alivePublicNouns = [...model.entities.values()].filter((e) => e.alive && (e.visibility ?? 'public') === 'public').length
+  const aliveVerbs = model.relations.size
+  const expectedNounCount = alivePublicNouns + model.vfsFileNouns
+  const expectedVerbCount = aliveVerbs + model.vfsContainsVerbs
+  expect(
+    await brain.getNounCount(),
+    `[${label}] getNounCount() mismatch: expected ${expectedNounCount} (alive public entities ${alivePublicNouns} + vfs file nouns ${model.vfsFileNouns})`
+  ).toBe(expectedNounCount)
+  expect(
+    await brain.getVerbCount(),
+    `[${label}] getVerbCount() mismatch: expected ${expectedVerbCount} (alive relations ${aliveVerbs} + vfs contains verbs ${model.vfsContainsVerbs})`
+  ).toBe(expectedVerbCount)
+
+  // (f) getCanonicalCounts(): ALL-visibility scalars (every tier) equal the
+  // model's alive totals including hidden tiers, plus the VFS's own
+  // contributions (both file nouns/verbs AND the once-measured root
+  // baseline). suspect must be false — every delete in this biography goes
+  // through brain.remove(), which always proves the record it decrements.
+  const ledger = await getCanonicalCountsFor(brain)
+  const aliveAllNouns = [...model.entities.values()].filter((e) => e.alive).length
+  const expectedNounsAll = aliveAllNouns + model.vfsFileNouns + model.vfsBaselineNouns
+  const expectedVerbsAll = aliveVerbs + model.vfsContainsVerbs + model.vfsBaselineVerbs
+  expect(
+    ledger.nouns.all,
+    `[${label}] getCanonicalCounts().nouns.all mismatch: expected ${expectedNounsAll} (alive incl. internal ${aliveAllNouns} + vfs file nouns ${model.vfsFileNouns} + vfs root baseline ${model.vfsBaselineNouns})`
+  ).toBe(expectedNounsAll)
+  expect(
+    ledger.verbs.all,
+    `[${label}] getCanonicalCounts().verbs.all mismatch: expected ${expectedVerbsAll} (alive relations ${aliveVerbs} + vfs contains verbs ${model.vfsContainsVerbs} + vfs root baseline ${model.vfsBaselineVerbs})`
+  ).toBe(expectedVerbsAll)
+  expect(ledger.nouns.counted, `[${label}] getCanonicalCounts().nouns.counted mismatch (should mirror getNounCount())`).toBe(expectedNounCount)
+  expect(ledger.verbs.counted, `[${label}] getCanonicalCounts().verbs.counted mismatch (should mirror getVerbCount())`).toBe(expectedVerbCount)
+  expect(ledger.suspect, `[${label}] getCanonicalCounts().suspect must be false — every delete in this biography proves its record`).toBe(false)
+}

tests/unit/brainy/lazy-notready-honor.test.ts

@@ -1,38 +1,49 @@
 /**
  * @module tests/unit/brainy/lazy-notready-honor
  * @description THE SILENT-EMPTY TRAP pin (found during a fleet adoption,
- * SELF-ENGINE-PAIR-STANDARD): under `disableAutoRebuild: true`, the lazy
+ * SELF-ENGINE-PAIR-STANDARD): under `disableAutoRebuild: true`, the OLD lazy
  * first-query path (`ensureIndexesLoaded`) assessed ONLY the vector index's
  * readiness — a native METADATA provider reporting not-ready (its strand
  * report) never blocked the completion latch, so the promised lazy rebuild
- * never fired and every `find()` silently returned `[]` on a populated
+ * never fired and every `find()` silently returned `[]` on a populated store
- * store (measured: 52 entities durable-but-unqueryable, first query
+ * (measured: 52 entities durable-but-unqueryable, first query 0ms/0 rows).
- * 0ms/0 rows). The law: a not-ready report from ANY provider falls through
+ *
- * to the rebuild — never a silent empty.
+ * RE-POINTED to the health-gate law (a read never builds; a rebuild runs
+ * entirely at open): `ensureIndexesLoaded()` is now a pure CHECK. A not-ready
+ * report from ANY provider — metadata, vector, or graph — makes it THROW the
+ * matching typed `*NotReadyError` rather than silently letting the read
+ * proceed, and it NEVER calls `rebuildIndexesIfNeeded` (that is entirely
+ * open()'s job now — see the second describe block below). The spirit is
+ * unchanged: a not-ready report from any single provider can never be
+ * shadowed into a silent empty result.
  *
  * White-box provider-double pattern per tests/unit/brainy/migration-deference.
  */
 import { describe, it, expect, afterEach, vi } from 'vitest'
-import { Brainy } from '../../../src/index.js'
+import { mkdtempSync, rmSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { Brainy, MetadataIndexNotReadyError } from '../../../src/index.js'
 import { NounType } from '../../../src/types/graphTypes.js'
 import { createTestConfig } from '../../helpers/test-factory.js'
 
 interface BrainInternals {
   index: { size(): number }
   metadataIndex: { isReady?: () => boolean }
-  lazyRebuildCompleted: boolean
+  ensureIndexesLoaded(): void
-  ensureIndexesLoaded(): Promise<void>
   rebuildIndexesIfNeeded(force?: boolean): Promise<void>
 }
 
 const brains: Brainy[] = []
+const dirs: string[] = []
 
 afterEach(async () => {
   for (const b of brains.splice(0)) await b.close().catch(() => {})
+  for (const d of dirs.splice(0)) rmSync(d, { recursive: true, force: true })
   vi.restoreAllMocks()
 })
 
-async function warmLazyBrain(): Promise<{ brain: Brainy; internals: BrainInternals }> {
+async function warmBrain(): Promise<{ brain: Brainy; internals: BrainInternals }> {
   const brain = new Brainy(createTestConfig({ disableAutoRebuild: true }))
   await brain.init()
   brains.push(brain)
@@ -40,36 +51,59 @@ async function warmLazyBrain(): Promise<{ brain: Brainy; internals: BrainInterna
     await brain.add({ data: `row ${i}`, type: NounType.Document, metadata: { i } })
   }
   const internals = brain as unknown as BrainInternals
-  internals.lazyRebuildCompleted = false // simulate the cold first query
   return { brain, internals }
 }
 
-describe('lazy path honors EVERY provider’s not-ready report', () => {
+describe('the read gate honors EVERY provider’s not-ready report', () => {
-  it('a not-ready METADATA provider blocks the completion latch and fires the rebuild', async () => {
+  it('a not-ready METADATA provider refuses loudly — it never lets a read proceed, and it never rebuilds', async () => {
-    const { internals } = await warmLazyBrain()
+    const { internals } = await warmBrain()
 
     // The trap's shape: vector side looks fine (populated), metadata
-    // provider says NOT ready — the old gate latched complete here.
+    // provider says NOT ready — the OLD gate silently latched complete here.
-    ;(internals.metadataIndex as { isReady?: () => boolean }).isReady = () => false
+    // The new gate refuses loudly instead; a read never triggers a rebuild.
-    const rebuildSpy = vi
+    internals.metadataIndex.isReady = () => false
-      .spyOn(internals, 'rebuildIndexesIfNeeded')
+    const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded').mockResolvedValue(undefined)
-      .mockResolvedValue(undefined)
 
-    await internals.ensureIndexesLoaded()
+    expect(() => internals.ensureIndexesLoaded()).toThrow(MetadataIndexNotReadyError)
-
+    expect(rebuildSpy, 'a read NEVER triggers a rebuild — building is entirely open()\'s job now').not.toHaveBeenCalled()
-    expect(rebuildSpy, 'not-ready metadata provider must fire the lazy rebuild').toHaveBeenCalledWith(true)
   })
 
-  it('control: all providers ready/unknown+populated → latch completes, no rebuild', async () => {
+  it('control: all providers ready/unknown+populated → the gate lets the read through, no rebuild', async () => {
-    const { internals } = await warmLazyBrain()
+    const { internals } = await warmBrain()
-    ;(internals.metadataIndex as { isReady?: () => boolean }).isReady = () => true
+    internals.metadataIndex.isReady = () => true
-    const rebuildSpy = vi
+    const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded').mockResolvedValue(undefined)
-      .spyOn(internals, 'rebuildIndexesIfNeeded')
-      .mockResolvedValue(undefined)
-
-    await internals.ensureIndexesLoaded()
 
+    expect(() => internals.ensureIndexesLoaded()).not.toThrow()
     expect(rebuildSpy).not.toHaveBeenCalled()
-    expect(internals.lazyRebuildCompleted).toBe(true)
   })
 })
+
+describe('the open-time build honors the same law: a needed rebuild runs at open, never deferred to a read', () => {
+  it('disableAutoRebuild:true does not defer a needed rebuild past open() on a reopened, populated store', async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'brainy-lazy-notready-honor-'))
+    dirs.push(dir)
+
+    const writer = new Brainy(createTestConfig({ disableAutoRebuild: true, storage: { type: 'filesystem', path: dir } }))
+    await writer.init()
+    for (let i = 0; i < 3; i++) {
+      await writer.add({ data: `row ${i}`, type: NounType.Document, metadata: { i } })
+    }
+    await writer.flush()
+    await writer.close()
+
+    // Fresh instance over the same store: its derived indexes start empty in
+    // memory, so open()'s rebuildIndexesIfNeeded MUST fire (and complete)
+    // before init() returns — even though disableAutoRebuild is true, there
+    // is no first-query lazy path left to defer to.
+    const reader = new Brainy(createTestConfig({ disableAutoRebuild: true, storage: { type: 'filesystem', path: dir } }))
+    const internals = reader as unknown as { rebuildIndexesIfNeeded(force?: boolean): Promise<void> }
+    const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded')
+
+    await reader.init()
+    brains.push(reader)
+
+    expect(rebuildSpy).toHaveBeenCalledTimes(1)
+    const rows = await reader.find({ where: { i: 1 } })
+    expect(rows.length).toBe(1)
+  }, 30000)
+})

tests/unit/brainy/metadata-provider-contract.test.ts

@@ -1,15 +1,18 @@
 /**
  * @module tests/unit/brainy/metadata-provider-contract
- * @description Brainy-side wiring of the two metadata-provider contract additions
+ * @description Brainy-side wiring of the metadata-provider contract.
- * confirmed with cor for the lockstep:
  *
- *  1. `probeConsistency()` — an OPTIONAL O(1) cold-open consistency sampler. On the
+ * `getIdsForFilter(filter, opts?)` — brainy passes a page bound on the UNSORTED
- *     first read, brainy calls it once; on `false` it self-heals via
+ * `find({ type, where, limit })` path so a native provider can early-stop. The JS
- *     `detectAndRepairCorruption()` (the metadata counterpart of the graph cold-load
+ * index ignores `opts`.
- *     guard). The native provider implements it; the JS index omits it (no-op).
+ *
- *  2. `getIdsForFilter(filter, opts?)` — brainy passes a page bound on the UNSORTED
+ * RETIRED (health-gate law): `probeConsistency()` / `ensureMetadataConsistencyProbed()`
- *     `find({ type, where, limit })` path so a native provider can early-stop. The JS
+ * — a read-time consistency probe that launches `detectAndRepairCorruption()` on
- *     index ignores `opts`.
+ * `false` was exactly the read-triggered dark rebuild the law forbids (a read must
+ * never start a store walk or a rebuild). The probe's diagnostic value lives on in
+ * `validateIndexConsistency()` / `repairIndex()`, which remain explicit, operator-invoked
+ * calls. The pin below confirms the retirement: `probeConsistency()` is never called by
+ * a read, even when a provider exposes it.
  *
  * These are unit tests of brainy's CALL behaviour (the real end-to-end honoring is
  * exercised by cor's combined matrix); they inject probe/spy hooks onto the live JS
@@ -19,7 +22,7 @@ import { describe, it, expect, beforeEach } from 'vitest'
 import { Brainy } from '../../../src/brainy'
 import { NounType } from '../../../src/types/graphTypes'
 
-describe('metadata-provider contract wiring (probeConsistency + getIdsForFilter opts)', () => {
+describe('metadata-provider contract wiring (getIdsForFilter opts)', () => {
   let brain: Brainy<any>
   let mi: any
 
@@ -29,47 +32,23 @@ describe('metadata-provider contract wiring (probeConsistency + getIdsForFilter
     await brain.add({ data: 'a', type: NounType.Thing, metadata: { kind: 'x' } })
     await brain.add({ data: 'b', type: NounType.Thing, metadata: { kind: 'y' } })
     mi = (brain as any).metadataIndex
-    ;(brain as any)._metadataConsistencyProbed = false // reset the one-shot guard
   })
 
-  it('calls probeConsistency once on cold open and self-heals via detectAndRepairCorruption on false', async () => {
+  it('RETIRED: a read never calls probeConsistency() / self-heals via detectAndRepairCorruption — that is the read-triggered dark rebuild the health-gate law forbids', async () => {
     let probes = 0
     let repairs = 0
-    mi.probeConsistency = async () => { probes++; return false } // corrupt → must repair
+    mi.probeConsistency = async () => { probes++; return false } // would-be corrupt signal
     const origRepair = mi.detectAndRepairCorruption.bind(mi)
     mi.detectAndRepairCorruption = async () => { repairs++; return origRepair() }
 
     await brain.find({ where: { kind: 'x' } })
-    expect(probes).toBe(1)
-    expect(repairs).toBe(1)
-
-    // Second read must NOT re-probe (once per brain).
     await brain.find({ where: { kind: 'y' } })
-    expect(probes).toBe(1)
-    expect(repairs).toBe(1)
-  })
 
-  it('does NOT repair when the probe reports healthy', async () => {
+    expect(probes).toBe(0) // no read-time probe exists anymore
-    let repairs = 0
+    expect(repairs).toBe(0) // and therefore no read-triggered self-heal either
-    mi.probeConsistency = async () => true // clean
-    const origRepair = mi.detectAndRepairCorruption.bind(mi)
-    mi.detectAndRepairCorruption = async () => { repairs++; return origRepair() }
 
-    await brain.find({ where: { kind: 'x' } })
+    delete mi.probeConsistency
-    expect(repairs).toBe(0)
+    mi.detectAndRepairCorruption = origRepair
-  })
-
-  it('a probe failure never breaks the read (best-effort, retried next time)', async () => {
-    let probes = 0
-    mi.probeConsistency = async () => { probes++; throw new Error('probe boom') }
-
-    // The read still succeeds despite the throwing probe.
-    const rows = await brain.find({ where: { kind: 'x' } })
-    expect(rows.length).toBe(1)
-    expect(probes).toBe(1)
-    // Guard reset on failure → the next read retries the probe.
-    await brain.find({ where: { kind: 'y' } })
-    expect(probes).toBe(2)
   })
 
   it('passes a page bound to getIdsForFilter on the unsorted find path (offset 0, brainy re-windows)', async () => {

tests/unit/brainy/migration-deference.test.ts

@@ -25,7 +25,7 @@
  */
 
 import { describe, it, expect, afterEach, vi } from 'vitest'
-import { Brainy } from '../../../src/index.js'
+import { Brainy, VectorIndexNotReadyError } from '../../../src/index.js'
 import { NounType } from '../../../src/types/graphTypes.js'
 import { createTestConfig } from '../../helpers/test-factory.js'
 import { BaseStorage } from '../../../src/storage/baseStorage.js'
@@ -43,9 +43,8 @@ interface BrainInternals {
   metadataIndex: { rebuild(...a: unknown[]): Promise<unknown> }
   graphIndex: { size(): number; rebuild(...a: unknown[]): Promise<unknown> }
   _indexEpochStale: boolean
-  lazyRebuildCompleted: boolean
   rebuildIndexesIfNeeded(force?: boolean): Promise<void>
-  ensureIndexesLoaded(): Promise<void>
+  ensureIndexesLoaded(): void
   storage: { readRawObject(p: string): Promise<unknown> }
 }
 
@@ -181,40 +180,40 @@ describe('rc.8 no-freeze migration deference (isMigrating / stampBrainFormat / b
     expect(idxSpy).toHaveBeenCalledTimes(1)
   })
 
-  // --- Hook 1: large-path first-query lazy force-rebuild deference ----------
+  // --- Hook 1: read-gate deference (RE-POINTED — the health-gate law retired
+  // the first-query lazy force-rebuild entirely: ensureIndexesLoaded() is now
+  // a pure CHECK that never calls rebuildIndexesIfNeeded, migrating or not.
+  // What survives from the original law is the DEFERENCE itself: a migrating
+  // provider's report is never judged by the gate — it neither throws nor
+  // rebuilds — while the exact same not-ready report on a NON-migrating
+  // provider throws the typed error instead of ever rebuilding.) ------------
 
-  it('lazy first-query force-rebuild is SKIPPED when the vector provider isMigrating()', async () => {
+  it('the read gate defers to a migrating vector provider — a not-ready report neither throws nor rebuilds', async () => {
-    // disableAutoRebuild routes first queries through ensureIndexesLoaded() (the
-    // large-brain lazy path that would otherwise force a blocking rebuild).
     const brain = await makeWarmBrain(2, { disableAutoRebuild: true })
     const internals = internalsOf(brain)
 
     const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded').mockResolvedValue(undefined)
-    // Simulate a cold/empty live vector index (cor is mid-swap, serving canonical).
+    // Simulate a not-ready live vector index (cor is mid-swap, serving canonical).
-    vi.spyOn(internals.index, 'size').mockReturnValue(0)
+    ;(internals.index as unknown as { isReady?: () => boolean }).isReady = () => false
-    internals.lazyRebuildCompleted = false
     setMigrating(internals.index, true)
 
-    await internals.ensureIndexesLoaded()
+    expect(() => internals.ensureIndexesLoaded()).not.toThrow()
-
+    // A query during cor's background swap must not trigger brainy's own
-    // A query during cor's background swap must not trigger brainy's blocking rebuild.
+    // rebuild — reads never rebuild in any case, migrating or not.
     expect(rebuildSpy).toHaveBeenCalledTimes(0)
   })
 
-  it('lazy first-query force-rebuild STILL fires when the vector provider is not migrating (control)', async () => {
+  it('the read gate THROWS for the same not-ready vector provider once migration clears (control)', async () => {
     const brain = await makeWarmBrain(2, { disableAutoRebuild: true })
     const internals = internalsOf(brain)
 
     const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded').mockResolvedValue(undefined)
-    vi.spyOn(internals.index, 'size').mockReturnValue(0)
+    ;(internals.index as unknown as { isReady?: () => boolean }).isReady = () => false
-    internals.lazyRebuildCompleted = false
     // No isMigrating → not deferring.
 
-    await internals.ensureIndexesLoaded()
+    expect(() => internals.ensureIndexesLoaded()).toThrow(VectorIndexNotReadyError)
-
+    // Still never rebuilds — the gate refuses loudly instead.
-    // Without deference, the cold empty index drives the lazy force-rebuild.
+    expect(rebuildSpy).toHaveBeenCalledTimes(0)
-    expect(rebuildSpy).toHaveBeenCalledTimes(1)
-    expect(rebuildSpy).toHaveBeenCalledWith(true)
   })
 
   // --- Hook 2: public stampBrainFormat() -----------------------------------

tests/unit/metadata-cold-read-guard.test.ts

@@ -3,10 +3,14 @@
  * reported cold `find({ where })` returning a silent `[]` on a freshly-opened
  * brain (a native metadata index that reports data but has not loaded its field
  * postings). This guard, the field-index counterpart of verifyGraphAdjacencyLive,
- * probes a known persisted value on the first filtered find(): if the index does
+ * probes a known persisted value on the first filtered find().
- * not serve it, brainy rebuilds and re-probes, and raises a loud
+ *
- * MetadataIndexNotReadyError only if the rebuild still can't serve — never a
+ * RE-POINTED to the health-gate law: the guard NEVER rebuilds and NEVER walks
- * silent empty result that misrepresents existing data.
+ * the store from a read — a read-path rebuild is exactly the dark-rebuild
+ * failure mode the law retires (open() alone owns building). When the probe
+ * cannot serve the known value it raises a loud MetadataIndexNotReadyError
+ * IMMEDIATELY, with no rebuild attempt in between — never a silent empty
+ * result that misrepresents existing data.
  *
  * The 8.0 JS index cold-loads correctly, so we simulate the cold native failure
  * mode by intercepting the provider's getIdsForFilter/rebuild.
@@ -42,37 +46,19 @@ describe('Metadata cold-read guard (#venue silent-[])', () => {
     mi.rebuild = origRebuild
   })
 
-  it('cold index: verifyMetadataLive self-heals via rebuild — find({where}) is correct, NOT silent []', async () => {
+  it('cold index: verifyMetadataLive REFUSES immediately — find({where}) throws MetadataIndexNotReadyError, NEVER a silent [], and NEVER a rebuild attempt', async () => {
     const mi = brain.metadataIndex
     const origGetIds = mi.getIdsForFilter.bind(mi)
+    let rebuilds = 0
     const origRebuild = mi.rebuild.bind(mi)
-    let cold = true
     brain._metadataVerified = false // re-arm the one-shot for this scenario
-    mi.getIdsForFilter = async (...a: any[]) => (cold ? [] : origGetIds(...a))
+    mi.getIdsForFilter = async () => [] // cold: the known value never resolves
-    mi.rebuild = async () => {
+    mi.rebuild = async () => { rebuilds++; return origRebuild() }
-      await origRebuild()
-      cold = false // the rebuild warms the postings
-    }
-    try {
-      const res = await brain.find({ where: { status: 'active' }, limit: 100 })
-      expect(res.length).toBe(1) // self-healed — the known entity is returned
-    } finally {
-      mi.getIdsForFilter = origGetIds
-      mi.rebuild = origRebuild
-    }
-  })
-
-  it('unrecoverably cold index: find({where}) throws MetadataIndexNotReadyError — never a silent []', async () => {
-    const mi = brain.metadataIndex
-    const origGetIds = mi.getIdsForFilter.bind(mi)
-    const origRebuild = mi.rebuild.bind(mi)
-    brain._metadataVerified = false
-    mi.getIdsForFilter = async () => [] // always cold; rebuild can't fix it
-    mi.rebuild = async () => {}
     try {
       await expect(brain.find({ where: { status: 'active' }, limit: 100 })).rejects.toBeInstanceOf(
         MetadataIndexNotReadyError
       )
+      expect(rebuilds).toBe(0) // the guard never rebuilds from a read — it refuses loudly instead
     } finally {
       mi.getIdsForFilter = origGetIds
       mi.rebuild = origRebuild

tests/unit/plugin-activation-loudness.test.ts

@@ -0,0 +1,71 @@
+/**
+ * @module tests/unit/plugin-activation-loudness
+ * @description The plugin-activation swallow closes. Two laws:
+ * (1) THE NOT-INSTALLED FREE PASS IS EXACT — a resolution failure earns the
+ *     silent skip ONLY when it names the probed package itself, terminated
+ *     where the name ends. A missing platform-binary SIBLING package
+ *     ("<pkg>-linux-x64-gnu" — what a deploy replacing node_modules
+ *     mid-restart leaves), an inner file path, or a dependency failure is a
+ *     BROKEN install and must fail loud. A production storm ran 90s of
+ *     throttled WASM behind this exact prefix-match hole.
+ * (2) A GRACEFUL DECLINE IS NARRATED ON THE ALWAYS-ON CHANNEL — activate()
+ *     returning false warns via prodLog, which `silent: true` cannot patch
+ *     away; a declined accelerator is never an invisible degrade.
+ */
+import { describe, it, expect, vi, afterEach } from 'vitest'
+import { Brainy } from '../../src/brainy.js'
+import { prodLog } from '../../src/utils/logger.js'
+
+const isNotInstalled = (error: unknown, pkg: string): boolean =>
+  (Brainy as unknown as {
+    isPackageNotInstalledError(e: unknown, p: string): boolean
+  }).isPackageNotInstalledError(error, pkg)
+
+const resolutionError = (message: string): Error => {
+  const e = new Error(message) as Error & { code?: string }
+  e.code = 'ERR_MODULE_NOT_FOUND'
+  return e
+}
+
+describe('the not-installed free pass is exact', () => {
+  const PKG = '@soulcraft/cor'
+
+  it('the package itself, quoted or bare → not-installed (the one free path)', () => {
+    expect(isNotInstalled(resolutionError(`Cannot find package '${PKG}' imported from /app/x.js`), PKG)).toBe(true)
+    expect(isNotInstalled(resolutionError(`Cannot find module ${PKG}`), PKG)).toBe(true)
+  })
+
+  it('a missing platform-binary SIBLING package is a broken install, never not-installed', () => {
+    expect(isNotInstalled(resolutionError(`Cannot find package '${PKG}-linux-x64-gnu' imported from /app`), PKG)).toBe(false)
+    expect(isNotInstalled(resolutionError(`Failed to resolve ${PKG}-darwin-arm64`), PKG)).toBe(false)
+  })
+
+  it('an inner file path or a non-resolution error is never not-installed', () => {
+    expect(isNotInstalled(resolutionError(`Cannot find module '/app/node_modules/${PKG}/native/b.node'`), PKG)).toBe(false)
+    expect(isNotInstalled(new Error(`dlopen failed: wrong ELF class in ${PKG}`), PKG)).toBe(false)
+  })
+})
+
+describe('a graceful decline is narrated on the always-on channel', () => {
+  afterEach(() => vi.restoreAllMocks())
+
+  it('activate() → false warns via prodLog even under silent: true', async () => {
+    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
+    const warn = vi.spyOn(prodLog, 'warn')
+    const brain: any = new Brainy({
+      requireSubtype: false,
+      storage: { type: 'memory' },
+      silent: true,
+      dimensions: 384
+    })
+    brain.use({ name: 'declining-accelerator', activate: async () => false })
+    await brain.init()
+    try {
+      expect(
+        warn.mock.calls.some((c) => String(c[0]).includes('"declining-accelerator" declined activation'))
+      ).toBe(true)
+    } finally {
+      await brain.close().catch(() => {})
+    }
+  })
+})

tests/unit/test-suite-coverage-guard.test.ts

@@ -63,6 +63,9 @@ function inGate(rel: string): boolean {
   return (
     rel.startsWith('tests/unit/') ||
     rel.startsWith('tests/integration/') ||
+    // The lifecycle biography lane — included by the integration config
+    // ('tests/lifecycle/**/*.test.ts'; see tests/lifecycle/README.md).
+    rel.startsWith('tests/lifecycle/') ||
     rel.endsWith('.unit.test.ts') ||
     rel.endsWith('.integration.test.ts')
   )

tests/unit/utils/indexReadiness.test.ts

@@ -0,0 +1,157 @@
+/**
+ * @module tests/unit/utils/indexReadiness
+ * @description Pins for the read-gate authority, {@link assessProviderHealth}, and
+ * its older sibling {@link assessIndexReadiness}. The health-gate law: a provider's
+ * NAMED, synchronous, O(1) health report — when exposed — REPLACES the `isReady()`/
+ * size-heuristic fallback as the read gate's source of truth. A throw from
+ * `healthReport()` is a CONTRACT VIOLATION (never read as healthy, never swallowed
+ * into "unknown"); an `unledgered` family is UNKNOWN (never healthy, never broken —
+ * `serving` is always the provider's own verdict, verbatim).
+ */
+import { describe, it, expect } from 'vitest'
+import { assessIndexReadiness, assessProviderHealth } from '../../../src/utils/indexReadiness.js'
+import type { HealthReport, LedgerInvariantResult } from '../../../src/plugin.js'
+
+function invariant(overrides: Partial<LedgerInvariantResult> = {}): LedgerInvariantResult {
+  return {
+    name: 'manifest-residency',
+    holds: true,
+    detail: 'ok',
+    heal: 'none',
+    source: 'ledger',
+    ...overrides
+  }
+}
+
+function report(overrides: Partial<HealthReport> = {}): HealthReport {
+  return {
+    provider: 'vector',
+    healthy: true,
+    serving: true,
+    invariants: [],
+    // A FIXED stamp, never Date.now(): the pin at :98 compares two
+    // independently-built reports, and a live clock made them differ by 1ms
+    // whenever the millisecond ticked between the two calls — a plant-lane
+    // red that had nothing to do with the code under test.
+    checkedAt: 1_700_000_000_000,
+    durationMs: 1,
+    generation: 1,
+    unledgered: [],
+    ...overrides
+  }
+}
+
+describe('assessIndexReadiness (legacy isReady() classifier)', () => {
+  it('unknown when the provider is null/undefined', () => {
+    expect(assessIndexReadiness(null)).toBe('unknown')
+    expect(assessIndexReadiness(undefined)).toBe('unknown')
+  })
+
+  it('unknown when isReady() is absent', () => {
+    expect(assessIndexReadiness({})).toBe('unknown')
+  })
+
+  it('ready / not-ready mirror isReady()', () => {
+    expect(assessIndexReadiness({ isReady: () => true })).toBe('ready')
+    expect(assessIndexReadiness({ isReady: () => false })).toBe('not-ready')
+  })
+})
+
+describe('assessProviderHealth — the read-gate authority', () => {
+  it('via "none": no provider at all', () => {
+    const a = assessProviderHealth(null)
+    expect(a.via).toBe('none')
+    expect(a.readiness).toBe('unknown')
+    expect(a.report).toBeNull()
+    expect(a.reasons.length).toBeGreaterThan(0)
+  })
+
+  it('via "size-heuristic": provider exposes neither healthReport() nor isReady()', () => {
+    const a = assessProviderHealth({})
+    expect(a.via).toBe('size-heuristic')
+    expect(a.readiness).toBe('unknown')
+    expect(a.report).toBeNull()
+  })
+
+  it('via "is-ready": provider exposes isReady() but no healthReport() — ready', () => {
+    const a = assessProviderHealth({ isReady: () => true })
+    expect(a.via).toBe('is-ready')
+    expect(a.readiness).toBe('ready')
+    expect(a.reasons).toEqual([])
+  })
+
+  it('via "is-ready": isReady() === false — not-ready with a reason', () => {
+    const a = assessProviderHealth({ isReady: () => false })
+    expect(a.via).toBe('is-ready')
+    expect(a.readiness).toBe('not-ready')
+    expect(a.reasons.length).toBeGreaterThan(0)
+  })
+
+  it('healthReport() present REPLACES isReady() — serving:true wins even if isReady() lies false', () => {
+    const p = { isReady: () => false, healthReport: () => report({ serving: true }) }
+    const a = assessProviderHealth(p)
+    expect(a.via).toBe('health-report')
+    expect(a.readiness).toBe('ready')
+  })
+
+  it('serving:true, healthy:true, no invariants failing → ready, no reasons', () => {
+    const p = { healthReport: () => report({ serving: true, healthy: true }) }
+    const a = assessProviderHealth(p)
+    expect(a.readiness).toBe('ready')
+    expect(a.reasons).toEqual([])
+    expect(a.report).toEqual(report({ serving: true, healthy: true }))
+  })
+
+  it('serving:false with a named heal:"rebuild" failing invariant → not-ready, reason names it', () => {
+    const failing = invariant({ name: 'posted-count-floor', holds: false, heal: 'rebuild', detail: 'posted 10 < canonical 20' })
+    const p = { healthReport: () => report({ serving: false, healthy: false, invariants: [failing] }) }
+    const a = assessProviderHealth(p)
+    expect(a.readiness).toBe('not-ready')
+    expect(a.reasons.some((r) => r.includes('posted-count-floor') && r.includes('heal:rebuild') && r.includes('posted 10 < canonical 20'))).toBe(true)
+  })
+
+  it('unledgered-only report (serving:true, no failing invariant) → ready, reason names the unledgered family', () => {
+    const p = { healthReport: () => report({ serving: true, healthy: true, unledgered: ['canonical-verb-coverage'] }) }
+    const a = assessProviderHealth(p)
+    expect(a.readiness).toBe('ready')
+    expect(a.reasons.some((r) => r.includes('unledgered') && r.includes('canonical-verb-coverage'))).toBe(true)
+  })
+
+  it('UNLEDGERED IS UNKNOWN: an unledgered family never flips a NOT-serving provider to ready', () => {
+    const failing = invariant({ holds: false, heal: 'rebuild', name: 'x' })
+    const p = { healthReport: () => report({ serving: false, healthy: false, invariants: [failing], unledgered: ['some-family'] }) }
+    const a = assessProviderHealth(p)
+    expect(a.readiness).toBe('not-ready')
+  })
+
+  it('serving:true, healthy:false with a heal:"repair" failure → still ready (degraded-but-serving)', () => {
+    const failing = invariant({ name: 'stale-counter', holds: false, heal: 'repair', detail: 'counter drift' })
+    const p = { healthReport: () => report({ serving: true, healthy: false, invariants: [failing] }) }
+    const a = assessProviderHealth(p)
+    expect(a.readiness).toBe('ready')
+    expect(a.reasons.some((r) => r.includes('stale-counter') && r.includes('heal:repair'))).toBe(true)
+  })
+
+  it('healthReport() that THROWS is a CONTRACT VIOLATION: not-ready, via health-report, reason names the throw — never "unknown"', () => {
+    const p = { healthReport: () => { throw new Error('mmap window busy') } }
+    const a = assessProviderHealth(p)
+    expect(a.via).toBe('health-report')
+    expect(a.readiness).toBe('not-ready')
+    expect(a.report).toBeNull()
+    expect(a.reasons.some((r) => r.includes('mmap window busy'))).toBe(true)
+    expect(a.readiness).not.toBe('unknown')
+  })
+
+  it('healthReport() that throws a non-Error value still produces a named reason (String(err))', () => {
+    const p = { healthReport: () => { throw 'boom' } }
+    const a = assessProviderHealth(p)
+    expect(a.readiness).toBe('not-ready')
+    expect(a.reasons.some((r) => r.includes('boom'))).toBe(true)
+  })
+
+  it('the returned report carries the generation for narration dedup', () => {
+    const p = { healthReport: () => report({ generation: 42 }) }
+    const a = assessProviderHealth(p)
+    expect(a.report?.generation).toBe(42)
+  })
+})

tests/unit/utils/metadataIndex-watermark.test.ts

@@ -11,8 +11,11 @@
  * Same rule, same verdict names as the shipped aggregation machinery
  * (AggregationIndex.stateAdoptionVerdict).
  *
- * The verdict is COMPUTED AND EXPOSED only — these pins assert no rebuild
+ * The verdict is computed at init and consumed via
- * trigger changed; acting on 'catchup' lands with the coordinator's wiring.
+ * {@link MetadataIndexManager.applyWatermarkCatchup} — the coordinator
+ * (`Brainy.performInit`) calls it right after `init()`, with an open fact
+ * scan when the verdict is `'catchup'`. This file pins both halves: the
+ * verdict computation (above) and the fold/no-op/demotion behavior below.
  */
 import { describe, it, expect, vi, afterEach } from 'vitest'
 import { v4 as uuidv4 } from 'uuid'
@@ -22,6 +25,46 @@ import {
 } from '../../../src/utils/metadataIndex.js'
 import { MemoryStorage } from '../../../src/storage/adapters/memoryStorage.js'
 import { prodLog } from '../../../src/utils/logger.js'
+import type { CommitFact, FactScanBatch, FactScanHandle } from '../../../src/db/factLog.js'
+
+/** A fact scan handle over an in-memory list of facts — batches them one
+ *  fact at a time (batch size is irrelevant to the fold, which reads
+ *  `batch.facts` only). */
+function fakeScan(facts: CommitFact[]): FactScanHandle {
+  return {
+    headGeneration: facts.length > 0 ? facts[facts.length - 1].generation : 0,
+    segmentCount: 1,
+    approxFactCount: facts.length,
+    async *batches(): AsyncGenerator<FactScanBatch> {
+      for (const fact of facts) {
+        yield {
+          facts: [fact],
+          firstGeneration: fact.generation,
+          lastGeneration: fact.generation,
+          factCount: 1,
+          byteSize: 0,
+          segmentId: 'fake'
+        }
+      }
+    },
+    summary: () => ({ factsYielded: facts.length, segmentsRead: 1 })
+  }
+}
+
+/** One noun after-image fact — the flat-record shape (no nested `metadata`
+ *  key), matching this file's existing `writeArtifact` convention. */
+function nounAdd(generation: number, id: string, metadata: Record<string, unknown>): CommitFact {
+  return {
+    generation,
+    timestamp: Date.now(),
+    ops: [{ kind: 'noun', id, record: { metadata, vector: null } }]
+  }
+}
+
+/** One noun tombstone fact. */
+function nounDelete(generation: number, id: string): CommitFact {
+  return { generation, timestamp: Date.now(), ops: [{ kind: 'noun', id, record: null }] }
+}
 
 /** Fresh storage with a controllable committed generation. */
 async function makeStorage(committed: number | null): Promise<MemoryStorage> {
@@ -169,3 +212,106 @@ describe('metadata index — watermark stamp + three-way load verdict', () => {
     expect(await storage.getMetadata(METADATA_INDEX_STAMP_KEY)).toBeNull()
   })
 })
+
+describe('metadata index — applyWatermarkCatchup (the coordinator door)', () => {
+  it("an 'adopt' verdict performs zero index writes", async () => {
+    const storage = await makeStorage(5)
+    await writeArtifact(storage, 5)
+    const index = await reopen(storage)
+    expect(index.watermarkVerdict()).toBe('adopt')
+
+    const addSpy = vi.spyOn(index, 'addToIndex')
+    const removeSpy = vi.spyOn(index, 'removeFromIndex')
+
+    const result = await index.applyWatermarkCatchup(null)
+
+    expect(result).toEqual({ action: 'noop' })
+    expect(addSpy).not.toHaveBeenCalled()
+    expect(removeSpy).not.toHaveBeenCalled()
+  })
+
+  it('a catchup window folding an add, an update (same id twice), and a delete → the index serves exactly the final state', async () => {
+    const storage = await makeStorage(5)
+
+    // Session 1: two pre-existing entities, stamped at generation 5.
+    const survivorId = uuidv4()
+    const deletedId = uuidv4()
+    {
+      const index = new MetadataIndexManager(storage)
+      await index.init()
+      await index.addToIndex(survivorId, { status: 'active' })
+      await index.addToIndex(deletedId, { status: 'active' })
+      index.stampWatermark(5)
+      await index.flush()
+    }
+
+    // The store advanced to generation 8 without another metadata flush —
+    // the exact shape a crash-then-adopt-reopen leaves behind.
+    setCommitted(storage, 8)
+
+    const index = await reopen(storage)
+    expect(index.watermarkVerdict()).toBe('catchup')
+    expect(index.watermarkGap()).toEqual({ from: 5, to: 8 })
+
+    const addedId = uuidv4()
+    const scan = fakeScan([
+      nounAdd(6, addedId, { status: 'new' }),       // add
+      nounAdd(7, addedId, { status: 'updated' }),   // update — same id twice
+      nounDelete(8, deletedId)                       // delete
+    ])
+
+    const result = await index.applyWatermarkCatchup(scan)
+
+    expect(result.action).toBe('caught-up')
+    expect(result.window).toEqual({ from: 5, to: 8 })
+    expect(result.factsApplied).toBe(3)
+    expect(result.nounsApplied).toBe(3)
+    expect(result.verbsApplied).toBe(0)
+
+    // Final state: the added/updated id serves ONLY its final value...
+    expect(await index.getIds('status', 'updated')).toEqual([addedId])
+    expect(await index.getIds('status', 'new')).toEqual([]) // stale value gone
+    // ...the deleted id is gone...
+    expect(await index.getIds('status', 'active')).toEqual([survivorId])
+    // ...and the untouched survivor is unaffected.
+    expect(await index.getIds('status', 'active')).toContain(survivorId)
+
+    // The window is certified: watermark stamped at `to`, and a fresh
+    // reopen now verdicts 'adopt'.
+    expect(index.watermark()).toBe(8)
+    const reopened = await reopen(storage)
+    expect(reopened.watermarkVerdict()).toBe('adopt')
+  })
+
+  it("a 'rescan' verdict runs the existing rebuild path instead of folding", async () => {
+    const storage = await makeStorage(9)
+    await writeArtifact(storage, 9)
+    setCommitted(storage, 4) // a truncated log pulled the watermark back — stamp ABOVE committed → rescan
+
+    const index = await reopen(storage)
+    expect(index.watermarkVerdict()).toBe('rescan')
+
+    const rebuildSpy = vi.spyOn(index, 'rebuild')
+    const result = await index.applyWatermarkCatchup(null)
+
+    expect(result.action).toBe('rescan')
+    expect(result.reason).toBeTruthy()
+    expect(rebuildSpy).toHaveBeenCalledTimes(1)
+  })
+
+  it("a 'catchup' verdict with no fact log available demotes to rebuild, narrated", async () => {
+    const storage = await makeStorage(5)
+    await writeArtifact(storage, 5)
+    setCommitted(storage, 8)
+
+    const index = await reopen(storage)
+    expect(index.watermarkVerdict()).toBe('catchup')
+
+    const rebuildSpy = vi.spyOn(index, 'rebuild')
+    const result = await index.applyWatermarkCatchup(null) // no scan — no fact log
+
+    expect(result.action).toBe('rescan')
+    expect(result.reason).toContain('no fact log')
+    expect(rebuildSpy).toHaveBeenCalledTimes(1)
+  })
+})

tests/unit/vector-cold-read-guard.test.ts

@@ -3,9 +3,14 @@
  * @description Pattern-A / Finding 1: a pure semantic find({ query }) has no
  * filter, so verifyMetadataLive never fires — nothing guarded the vector index.
  * A cold native vector index that loaded its COUNT but not its serving structure
- * returned a silent []. verifyVectorLive() closes that: honest isReady() first,
+ * returned a silent []. verifyVectorLive() closes that: the health-report/isReady()
- * else a known-vector self-match probe; self-heal (rebuild) or throw
+ * authority first, else a known-vector self-match probe.
- * VectorIndexNotReadyError — never a silent empty result.
+ *
+ * RE-POINTED to the health-gate law: the guard NEVER rebuilds and NEVER walks
+ * the store from a read — a read-path rebuild is exactly the dark-rebuild
+ * failure mode the law retires (open() alone owns building). A not-serving
+ * signal (from either strategy) THROWS VectorIndexNotReadyError immediately,
+ * with no rebuild attempt in between — never a silent empty result.
  */
 import { describe, it, expect, beforeEach } from 'vitest'
 import { Brainy, NounType, VectorIndexNotReadyError } from '../../src/index.js'
@@ -34,50 +39,37 @@ describe('Vector cold-read guard (verifyVectorLive) — silent-[] on cold semant
     vi.rebuild = origRebuild
   })
 
-  it('cold index: verifyVectorLive self-heals via rebuild — semantic find is correct, NOT silent []', async () => {
+  it('cold index (no isReady()): verifyVectorLive REFUSES immediately — throws VectorIndexNotReadyError, NEVER rebuilds', async () => {
-    const vi = brain.index
-    const origSearch = vi.search.bind(vi)
-    const origRebuild = vi.rebuild.bind(vi)
-    let cold = true
-    brain._vectorVerified = false
-    // size()>0 (count present) but search returns nothing until a rebuild warms it.
-    vi.search = async (...a: any[]) => (cold ? [] : origSearch(...a))
-    vi.rebuild = async (...a: any[]) => { await origRebuild(...a); cold = false }
-    try {
-      const res = await brain.find({ query: 'x', searchMode: 'semantic', limit: 100 })
-      expect(res.length).toBeGreaterThan(0) // self-healed
-    } finally {
-      vi.search = origSearch; vi.rebuild = origRebuild
-    }
-  })
-
-  it('unrecoverably cold index: semantic find throws VectorIndexNotReadyError', async () => {
     const vi = brain.index
     const origSearch = vi.search.bind(vi)
+    let rebuilds = 0
     const origRebuild = vi.rebuild.bind(vi)
     brain._vectorVerified = false
-    vi.search = async () => []      // always cold; rebuild can't fix it
+    // size()>0 (count present) but search never returns a hit for the known vector.
-    vi.rebuild = async () => {}
+    vi.search = async () => []
+    vi.rebuild = async (...a: any[]) => { rebuilds++; return origRebuild(...a) }
     try {
       await expect(
         brain.find({ query: 'x', searchMode: 'semantic', limit: 100 })
       ).rejects.toBeInstanceOf(VectorIndexNotReadyError)
+      expect(rebuilds).toBe(0) // the guard never rebuilds from a read — it refuses loudly instead
     } finally {
       vi.search = origSearch; vi.rebuild = origRebuild
     }
   })
 
-  it('native provider reporting isReady()===false rebuilds, then serves', async () => {
+  it('native provider reporting isReady()===false THROWS immediately — never rebuilds', async () => {
     const vi = brain.index
+    let rebuilds = 0
     const origRebuild = vi.rebuild.bind(vi)
-    let ready = false
     brain._vectorVerified = false
-    vi.isReady = () => ready
+    vi.isReady = () => false
-    vi.rebuild = async (...a: any[]) => { await origRebuild(...a); ready = true }
+    vi.rebuild = async (...a: any[]) => { rebuilds++; return origRebuild(...a) }
     try {
-      const res = await brain.find({ query: 'x', searchMode: 'semantic', limit: 100 })
+      await expect(
-      expect(ready).toBe(true) // rebuild ran because isReady() was false
+        brain.find({ query: 'x', searchMode: 'semantic', limit: 100 })
-      expect(res).toBeDefined()
+      ).rejects.toBeInstanceOf(VectorIndexNotReadyError)
+      expect(rebuilds).toBe(0) // a not-ready report throws immediately — it is never a rebuild trigger
     } finally {
       delete vi.isReady; vi.rebuild = origRebuild
     }