brainy/RELEASES.md

@soulcraft/brainy — Release Notes for Consumers

This file is the quick reference for Soulcraft product sessions tracking Brainy changes. Full auto-generated changelog: CHANGELOG.md · Releases: https://github.com/soulcraftlabs/brainy/releases

How to use: Brainy is the underlying data engine for Workshop, Venue, Academy, and Collective. The SDK wraps it — most products never call Brainy directly. Read this when:

• Upgrading @soulcraft/brainy in the SDK or a product
• Debugging data, query, or storage behaviour
• A new Brainy feature is available that SDK should expose

---

v7.29.0 — 2026-06-04

Affected products: anyone modeling entities with per-product sub-classification — every consumer that's been reaching for metadata.kind, a custom metadata.subtype field, a data.kind shape inside the payload, or similar ad-hoc conventions. Additive; drop-in from 7.28.x. No deprecations.

New — subtype promoted to a top-level standard field

subtype?: string is now a first-class standard field on every entity, alongside type / confidence / weight. Use it as the platform-standard primitive for sub-classifying entities within a NounType (Person → 'employee' / 'customer'; Document → 'invoice' / 'contract'; Event → 'milestone' / 'meeting'):

await brain.add({
  data: 'Avery Brooks — runs the AI lab',
  type: NounType.Person,
  subtype: 'employee',                  // top-level write param
  metadata: { department: 'ai-lab' }
})

// Fast-path filter — column-store hit, not metadata fallback:
const employees = await brain.find({ type: NounType.Person, subtype: 'employee' })

// Set membership:
const internal = await brain.find({
  type: NounType.Person,
  subtype: ['employee', 'contractor']
})

Flat string, no hierarchy — your vocabulary, your choice. Brainy stores and counts, never validates.

New — O(1) subtype counts via the persisted rollup

A new _system/subtype-statistics.json rollup is maintained incrementally as entities are added, updated, and deleted — mirroring the existing nounCountsByType machinery with the same self-heal behavior on poison detection. Counts are O(1) at billion scale:

brain.counts.bySubtype(NounType.Person)
// → { employee: 12, customer: 847, vendor: 34 }

brain.counts.bySubtype(NounType.Person, 'employee')   // O(1) point count
// → 12

brain.counts.topSubtypes(NounType.Person, 3)
// → [['customer', 847], ['employee', 12], ['vendor', 34]]

brain.subtypesOf(NounType.Person)
// → ['customer', 'employee', 'vendor']

New — brain.trackField() for other metadata facets

For facets that aren't the primary sub-classification (status, source, role, paradigm), trackField registers a field for cardinality + per-NounType breakdown stats without promoting each one to a top-level slot. Piggybacks on the existing aggregation engine, so backfill-on-define applies — registering on a populated brain scans existing entities on the first query:

brain.trackField('status', { perType: true })

await brain.counts.byField('status')
// → { todo: 12, doing: 3, done: 47 }

await brain.counts.byField('status', { type: NounType.Task })
// → { todo: 8, doing: 2, done: 30 }

// Opt-in vocabulary validation:
brain.trackField('priority', { values: ['low', 'medium', 'high'] })
// brain.add({ ..., metadata: { priority: 'urgent' } }) → throws

New — generic brain.migrateField() for one-shot rewrites

Streams every entity and copies a value from one field path to another. Supports top-level standard fields, metadata.*, and data.* paths; idempotent; with optional readBoth: true deprecation window that preserves the source field alongside the new one:

// Phase 1: dual-populate (legacy readers still work)
await brain.migrateField({
  from: 'metadata.kind',
  to: 'subtype',
  readBoth: true
})

// ...readers migrate to subtype at their own pace...

// Phase 2: clear the source field
await brain.migrateField({ from: 'metadata.kind', to: 'subtype' })
// → { scanned: 1500, migrated: 1500, skipped: 0, errors: [] }

Supports batchSize and onProgress for large brains.

Aggregation composition

subtype is a standard-field group-by dimension out of the box — no where: wrapper, no metadata-fallback overhead:

await brain.find({
  aggregate: {
    groupBy: ['type', 'subtype'],
    metrics: { count: { op: 'COUNT' } }
  }
})
// [
//   { groupKey: { type: 'person',   subtype: 'customer' }, count: 847 },
//   { groupKey: { type: 'person',   subtype: 'employee' }, count: 12 },
//   { groupKey: { type: 'document', subtype: 'invoice'  }, count: 2103 },
//   ...
// ]

Cortex compatibility

Subtype works under Cortex out of the box via auto-field-indexing. Cortex will land its own native-side query-planner recognition + subtypeCountsByType native rollup in the next Cortex release for full parity with type's fast path. Not a Brainy blocker — subtype reads/writes function correctly with current Cortex.

Docs

Full guide: docs/guides/subtypes-and-facets.md. Subtype is documented as a core primitive throughout README.md, docs/DATA_MODEL.md, docs/architecture/finite-type-system.md, docs/api/README.md, and docs/QUERY_OPERATORS.md.

---

v7.24.0 — 2026-05-26

Affected products: aggregation/reporting users + anyone calling extractEntities on multi-entity text. Additive; drop-in from 7.23.x.

New — array-unnest groupBy (tag frequency / faceted counts)

A groupBy dimension can now be { field, unnest: true }: the field holds an array and the entity contributes once per distinct element. Enables tag-frequency / label-count style aggregates:

brain.defineAggregate({
  name: 'tag_frequency',
  source: { type: NounType.Document },
  groupBy: [{ field: 'tags', unnest: true }],
  metrics: { count: { op: 'count' } }
})
// queryAggregate('tag_frequency', { orderBy: 'count', order: 'desc' })

Duplicate elements on one entity count once; an entity with an empty/missing array joins no group.

Perf — entity extraction batch-embeds candidates

extractEntities / extractConcepts now embed all unique candidate spans in a single embedBatch call instead of one embed() per candidate (N sequential model calls before). No behavior change — and with vectors reliably available, the embedding signal more consistently reinforces correct types (e.g. clearer Organization confidence). Falls back to per-candidate embedding if a batch call fails.

---

v7.23.0 — 2026-05-26

Affected products: anyone using aggregation (stats/dashboards), graph traversal, or entity extraction. Adds two report APIs and fixes three correctness gaps surfaced by BR-ADV-FEATURES-BUN. Drop-in upgrade from 7.22.x.

New — brain.queryAggregate(name, params)

A first-class report API returning the clean AggregateResult[] shape ({ groupKey, metrics, count }[]) directly, instead of the search-Result wrapper that find({ aggregate }) returns. Accepts where / having / orderBy / order / limit / offset.

New — HAVING (filter groups by metric value)

find({ aggregate, having: { revenue: { greaterThan: 1000 } } }) (and the same on queryAggregate) filters groups by their computed metrics — the analytics equivalent of SQL HAVING, complementing where (which filters group keys). Evaluated per group: O(groups), independent of entity count.

Fix — aggregates now backfill when defined over existing data (R1)

Defining an aggregate on a store that already holds matching entities returned [] because write-time hooks only saw future writes. It now backfills from existing entities on first query (one-time scan via getNouns, then incremental) — storage-agnostic, so it works under durable backends (Cortex) where a brain reopens pre-populated. Also: groupBy:['noun'] now resolves to the entity type instead of a single null group. find({ aggregate }) rows now expose groupKey/metrics/count at the top level (previously only under .metadata).

Fix — multi-hop find({ connected: { depth, via } }) (traversal)

depth and via are now honored at every hop (previously only the immediate neighbour was returned, and verb filtering applied to hop 1 only). The BFS is bounded by limit.

Fix — entity extraction type accuracy (R3)

extractEntities no longer lets a type indicator in one candidate's surrounding text bleed onto neighbours (e.g. "Corp" in "Sarah Chen founded Acme Corp" no longer types "Sarah Chen" as Organization). Each candidate is typed by its own span; context may only reinforce the same type.

---

v7.22.1 — 2026-05-26

Affected products: Anyone using extractEntities() / extractConcepts(), native aggregation (find({ aggregate })), or multi-hop graph traversal (find({ connected: { depth } })). Three advanced-API correctness fixes — all reproduce on Node, so they were not Bun-specific despite the original report (BR-ADV-FEATURES-BUN).

Entity/concept extraction no longer returns []

extractEntities() / extractConcepts() returned empty for entity-rich text. The SmartExtractor ensemble scored agreeing signals with a weighted sum against an absolute 0.60 gate, so a confident low-weight signal (e.g. a name pattern at 0.82) lost selection to a mediocre high-weight signal that then failed the gate — dropping the whole result. It now selects and gates on a normalized weighted average. Also: the confidence option now actually controls the threshold (was a dead hardcoded 0.60), and the embedding-signal timeout was raised 100ms → 2000ms so the neural signal isn't silently dropped on slower runtimes.

Known limitation: type accuracy on dense multi-entity sentences is still imperfect — a strong indicator in one entity's surrounding text can bleed onto neighbours. Tracked separately.

find({ aggregate }) exposes groupKey / metrics / count

Aggregation always computed correct values, but rows nested them under .metadata, so callers expecting the documented AggregateResult shape saw empty-looking rows. Those three fields are now also present at the top level of each result row.

Multi-hop find({ connected: { depth } }) honours depth

Previously returned only the immediate (1-hop) neighbour at any depth because the graph-search path ignored depth / via. It now performs the full depth-aware traversal.

---

v7.22.0 — 2026-05-15

Affected products: All. Fixes a silent-data-loss class affecting find() and brain.stats(), plus Cortex-compatibility regression from 7.21.0. Recommended upgrade for everyone on 7.20.x or 7.21.x.

Two correctness fixes

1. find({ where }) no longer silently returns [] (BR-FIND-WHERE-ZERO)

The 7.20.0 column-store refactor deleted the legacy sparse-index write path but left getStats() and getIds() reading from sparse indices. New workspaces had no sparse-index files, so:

• brain.stats().entityCount was 0 regardless of actual entity count
• find({ where: { ... } }) returned [] regardless of actual matches
• rebuildIndexesIfNeeded() saw 0 entries → fired the [Brainy] CRITICAL ... Second rebuild result: 0 entries log → application saw no indexed data

7.22.0 makes the ColumnStore the single source of truth post-7.20.0:

• MetadataIndex.getStats() reads from ColumnStore.getIndexedFields() and idMapper.size. Entity count is now accurate across writer → close → reader-open cycles.
• MetadataIndex.getIdsFromChunks() throws BrainyError(FIELD_NOT_INDEXED) when neither column store nor legacy sparse index has the field.
• MetadataIndex.getIdsForFilter() catches per-clause, logs [brainy] find() where-clause referenced unindexed field(s): ..., returns []. Production find() is now consistent with brain.explain()'s path: 'none' diagnostic.

Separately, BaseStorage.getNounType() was hardcoded to return 'thing' since a type-cache removal in commit 42ae5be. Every noun save attributed the entity to 'thing' regardless of its actual type, poisoning _system/type-statistics.json and brain.stats().entitiesByType. 7.22.0 restores type-correct attribution:

• New nounTypeByIdCache: Map<string, NounType> on BaseStorage, populated in saveNounMetadata_internal and consumed in saveNoun_internal.
• New flushCounts() override that persists nounCountsByType / verbCountsByType alongside the per-entity counter. Readers opening the same directory after a writer flush now see correct per-type counts.

Self-heal at init. If loadTypeStatistics() detects the poisoned-state signature (all nouns attributed to 'thing' with multiple non-thing entities on disk), it auto-runs rebuildTypeCounts() once and rewrites the file. A [BaseStorage] Detected poisoned type-statistics.json signature ... warning is logged. Operators don't need to take any action — the first 7.22 open of a directory poisoned by 7.20.0/7.21.0 fixes it.

brainy inspect repair can also be used to manually trigger rebuildTypeCounts(). It's now public on BaseStorage.

2. Cortex 2.2.x no longer crashes 7.21.0 boot (BR-DEFENSIVE-INTERFACE)

7.21.0 added new storage-adapter methods (supportsMultiProcessLocking, acquireWriterLock, etc.) and called them unconditionally. Cortex 2.2.0's mmap storage adapter bundles a pre-7.21 BaseStorage and doesn't define them, so Venue's 7.21.0 upgrade attempt threw TypeError: this.storage.supportsMultiProcessLocking is not a function at boot.

7.22.0 introduces hasStorageMethod(name) on Brainy and guards every new- method call site. Older adapters degrade with a one-line warning at init:

[brainy] Storage adapter `CortexMmapStorage` predates the 7.21
multi-process methods. Writer locking and the flush-request RPC are
disabled for this directory. Upgrade the plugin (e.g.
`@soulcraft/cortex` ≥2.3.0) for full enforcement.

Dead-code cleanup

Removed MetadataIndexManager.dirtyChunks, dirtySparseIndices, and the flushDirtyMetadata() no-op machinery. These accumulators stopped being populated when the sparse-index write path was deleted in 7.20.0; the remaining 6 callers wasted async hops on an empty Map iteration.

Upgrade notes

• Behaviour change: find({ where: { unindexedField: ... } }) previously returned [] silently. It now logs a one-line warning and still returns []. The diagnostic message names the field — use brain.explain({ where: { ... } }) for full diagnosis. No code change needed for callers that already handle empty results.
• Behaviour change (good): brain.stats() and brain.health() now report accurate per-type counts. If you previously relied on the buggy entitiesByType.thing over-count, update consumers.
• No API breaks. Pure additive on the public surface.

Cortex consumers

Cortex 2.2.x continues to work against 7.22.0 thanks to the defensive guards, but for full multi-process protection on Cortex-backed stores and to make sure Cortex's native MetadataIndex picks up the find-where-zero fix, Cortex 2.3.0 is recommended. Tracked as CX-MULTIPROC-METHOD in the internal platform handoff.

---

v7.21.0 — 2026-05-15

Affected products: All consumers using filesystem storage (Venue, Workshop dev, local development).

Multi-process safety + first-class read-only inspector

Filesystem storage now enforces single-writer, many-reader. Previously, opening a second writer process against a live data directory silently produced wrong query results — no error, no warning, just empty or stale data. This release replaces that footgun with a hard refusal at init time and a dedicated read-only inspection mode.

New: Brainy.openReadOnly()

const reader = await Brainy.openReadOnly({
  storage: { type: 'filesystem', rootDirectory: '/data/brain' }
})
const bookings = await reader.find({ where: { entityType: 'booking' } })

• Does NOT acquire the writer lock — coexists with a live writer.
• Every mutation method throws Cannot mutate a read-only Brainy instance.
• flush() and close() are safe (no-op + clean shutdown).

New: writer lock at init

• new Brainy({ ... }) (default mode: 'writer') acquires <rootDir>/locks/_writer.lock containing { pid, hostname, startedAt, lastHeartbeat, version }.
• A second writer on the same directory throws with the PID, hostname, heartbeat, and a pointer to openReadOnly().
• Stale-lock detection: same hostname + dead PID OR heartbeat > 60s ago → overwritten with a warning.
• Heartbeat: writer rewrites lastHeartbeat every 10s (unref'd timer).
• Override: pass { force: true } to bypass when you've verified the existing lock is stale.

New: brain.requestFlush({ timeoutMs })

Cross-process RPC for inspectors to force a fresh snapshot:

• In-process: just calls flush().
• Out-of-process: writes a request file, polls for ack. Times out gracefully.
• Watcher runs in every writer instance (filesystem only).

New: brain.stats()

Operator-facing summary: entityCount, entitiesByType, relationCount, relationsByType, fieldRegistry, indexHealth, storage.backend, writerLock, version. Designed for /api/health endpoints and incident triage.

New: brain.explain(findParams)

Shows which index path serves each where clause: column-store | sparse-chunked | none. This is the answer to "why is find() returning empty?" — path: "none" means the field has no index entries and the query will silently return []. Includes notes on likely causes (writer hasn't flushed; typo; field genuinely absent).

New: brain.health()

Invariant-check battery: HNSW vs metadata count parity, field registry sanity, _seeded entity sweep, writer heartbeat freshness. Returns { overall: 'pass' | 'warn' | 'fail', checks: [...] }.

New: brainy inspect CLI (13 subcommands)

All read-only by default (internally uses openReadOnly()):

brainy inspect stats   <path>
brainy inspect find    <path> --type Event --where '{"status":"paid"}' --limit 20
brainy inspect get     <path> <id>
brainy inspect relations <path> <id> --direction both
brainy inspect explain <path> --where '{"entityType":"booking"}'
brainy inspect health  <path>
brainy inspect sample  <path> --type Event --n 20
brainy inspect fields  <path>
brainy inspect dump    <path> --type Event > backup.jsonl
brainy inspect watch   <path> --type Event
brainy inspect backup  <path> /backups/brain.tar
brainy inspect repair  <path>           # writer mode — stop live writer first
brainy inspect diff    <pathA> <pathB>

Default behaviour: ask the writer to flush via the RPC first (skip with --no-fresh).

Brainy + Cortex

Cortex segments (*.cidx) are immutable mmap files; MANIFEST.json uses atomic rename. The single writer lock at <rootDir>/locks/_writer.lock covers both Brainy and Cortex. Read-only inspectors mmap Cortex segments with zero coordination.

What's NOT enforced yet

• Cloud storage backends (S3, GCS, R2, Azure) — no multi-process locking. A best-effort warning logs in writer mode against non-filesystem backends.
• The find({ where })-returns-0 root-cause bug — tracked separately. The new brain.explain() and brain.health() surface it loudly (path: 'none', index-parity warn) instead of letting it be silent.

Upgrade notes

• Default behaviour change: opening a Brainy directory in writer mode while another writer is live now THROWS where it previously silently produced wrong results. If you have scripts that intentionally co-opened a writer directory, switch them to Brainy.openReadOnly() or pass { force: true }.
• Cloud backends unchanged — no lock acquisition for S3/GCS/R2/Azure.
• All existing APIs unchanged. Pure addition.

Docs

• README "Single-Writer Model" section.
• docs/concepts/multi-process.md — full model + Cortex compatibility.
• docs/guides/inspection.md — operator recipes.
• JSDoc on every new API.

---

v7.19.10 — 2026-02-24

Affected products: All Bun/ESM consumers (Workshop, Venue, Academy, SDK)

ESM crypto fix in SSTable

Replaced require('crypto') with import { createHash } from 'node:crypto' in the SSTable implementation. Fixes a crash in Bun and strict ESM environments where CommonJS require is unavailable.

No API changes — upgrade and redeploy.

---

v7.19.2 — 2026-02-18

Affected products: All

Metadata index cleanup on delete

Fixed: metadata indexes were not cleaned up after delete() / deleteMany(). Stale index entries could cause phantom results in metadata-filtered queries after deletion.

No API changes. If you were seeing ghost results in filtered queries, this fixes it.

---

v7.18.0 — 2026-02-16

Affected products: Workshop, Venue, Academy (analytics, reporting, session summaries)

Aggregation engine

New brain.aggregate() API — incremental SUM, COUNT, AVG, MIN, MAX with GROUP BY and time window support. Computes over entity collections without loading all records into memory.

const result = await brain.aggregate({
  collection: 'bookings',
  metrics: [
    { field: 'revenue', fn: 'SUM' },
    { field: 'id', fn: 'COUNT' },
  ],
  groupBy: 'staffId',
  timeWindow: { field: 'createdAt', from: startOfMonth, to: now },
})

SDK exposure: sdk.brainy.aggregate() — available once SDK is updated to pass through.

---

v7.17.0 — 2026-02-09

Affected products: All (schema evolution, data migrations)

Migration system

New brain.migrate() API with error handling, validation, and enterprise hardening. Run schema migrations reliably across Brainy data directories.

await brain.migrate({
  version: 3,
  up: async (brain) => {
    // transform entities, rename fields, etc.
  },
})

---

v7.16.0 — 2026-02-09

Affected products: All

Data/metadata separation enforced + numeric range queries

• Entity data and metadata fields are now strictly separated at the storage layer
• Numeric range queries now supported in metadata filters: { age: { $gte: 18, $lt: 65 } }
• Fixes edge cases where mixed data/metadata storage caused inconsistent query results

Breaking for anyone storing numeric values in metadata and relying on range queries: verify your filter syntax matches the new $gte/$lte/$gt/$lt operators.

---

v7.15.5 — 2026-02-02

Affected products: Anyone using @soulcraft/cortex plugin

Plugin opt-in clarified

Cortex and other plugins are opt-in. Pass explicitly:

new Brainy({ plugins: ['@soulcraft/cortex'] })

Without plugins, no external plugins are loaded regardless of what's installed.

---

v7.15.2 — 2026-02-01

Affected products: All (data safety)

Graph LSM flush on close

Fixed: graph LSM-trees were not flushed on brain.close(), risking data loss across restarts. Graph edges written in the final seconds before shutdown are now guaranteed to be persisted.

No API changes — upgrade immediately if running Brainy in a long-lived server process.