diff --git a/.forgejo/workflows/ci.yml b/.forgejo/workflows/ci.yml
index da5887f6..5e93cd96 100644
--- a/.forgejo/workflows/ci.yml
+++ b/.forgejo/workflows/ci.yml
@@ -5,10 +5,6 @@ name: CI
 # sequential, so tag-triggered matrix jobs (~22 min) would queue AHEAD of the
 # tag's publish-source run and starve every release (observed on 8.10.3 and
 # 9.0.0: the publish sat behind the tag's own redundant CI).
-concurrency:
-  group: ci-${{ github.ref }}
-  cancel-in-progress: true
-
 on:
   push:
     branches: ['**']
diff --git a/.forgejo/workflows/publish-source.yml b/.forgejo/workflows/publish-source.yml
index 6bd42b2a..58cb1d30 100644
--- a/.forgejo/workflows/publish-source.yml
+++ b/.forgejo/workflows/publish-source.yml
@@ -12,11 +12,6 @@ on:
   push:
     tags:
       - 'v*'
-  workflow_dispatch:
-    inputs:
-      ref_reason:
-        description: 'why this manual run (e.g. tag event dropped)'
-        required: false
 
 jobs:
   publish:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a54d609e..57c83f6b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,23 @@
 
 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.
 
+### [10.4.7](https://source.soulcraft.com/soulcraftlabs/open-brainy/compare/v10.4.6...v10.4.7) (2026-09-01)
+
+- fix(storage): counts persistence is single-flight, coalesced, and never races its own temp file (5e3b343a)
+
+
+### [10.4.6](https://source.soulcraft.com/soulcraftlabs/open-brainy/compare/v10.4.5...v10.4.6) (2026-08-31)
+
+- fix(transact): metadata-index ops take their JSON-safe view at the crossing, not at construction (73500e7d)
+
+
+### [10.4.5](https://source.soulcraft.com/soulcraftlabs/open-brainy/compare/v10.4.4...v10.4.5) (2026-08-31)
+
+- build(release): the docs-push step retires — this engine documents itself in its own repository (d6bcb14f)
+- fix(generations): a sealed segment may only declare the generations it holds (a963a744)
+- fix(recovery): a torn generation-log tail is a terminal verdict, never a wait (c9930871)
+
+
 ### [10.4.4](https://source.soulcraft.com/soulcraftlabs/open-brainy/compare/v10.4.3...v10.4.4) (2026-08-28)
 
 - fix(vfs): the old-root sweep narrates only when it has something to say (d49148e1)
diff --git a/package-lock.json b/package-lock.json
index c4f66561..9add5a2e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@soulcraftlabs/brainy",
-  "version": "10.4.4",
+  "version": "10.4.7",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@soulcraftlabs/brainy",
-      "version": "10.4.4",
+      "version": "10.4.7",
       "license": "MIT",
       "dependencies": {
         "@msgpack/msgpack": "^3.1.2",
diff --git a/package.json b/package.json
index 06ce0253..7c74b0fd 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@soulcraftlabs/brainy",
-  "version": "10.4.4",
+  "version": "10.4.7",
   "brainyContract": 1,
   "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",
diff --git a/releases/brainy.json b/releases/brainy.json
deleted file mode 100644
index 8f61c7f2..00000000
--- a/releases/brainy.json
+++ /dev/null
@@ -1,76 +0,0 @@
-{
-  "product": "brainy",
-  "entries": [
-    {
-      "version": "11.0.5",
-      "date": "2026-09-02",
-      "headline": "Graph-first finds in production, and opens that stop rescanning history",
-      "items": [
-        "find({ connected, where }) now walks the neighbours first and filters only those rows through a native door — correct at every page and O(neighbours), never the whole store.",
-        "related() with a list of verb types returns every requested kind (a fast path had silently kept only the first).",
-        "Deferred-embedding recovery resumes from a low-water mark instead of rescanning the whole generation log at every open — measured at two minutes on a large brain, now milliseconds."
-      ],
-      "url": null,
-      "thumb": null
-    },
-    {
-      "version": "11.0.4",
-      "date": "2026-09-01",
-      "headline": "Closes in milliseconds, index rebuilds without the disk-sync storm",
-      "items": [
-        "close() no longer pays deferred compaction or waits out an in-flight rebuild — measured 8 ms against the 4-minute closes it replaces; deferred work resumes at the next open, in the background.",
-        "The metadata index's rebuild syncs to disk per shard instead of per row, and the durability point moved to the publish step — the same guarantee, a fraction of the disk traffic.",
-        "A new native filter door evaluates queries over exactly the candidate rows a graph walk found, never the whole store."
-      ],
-      "url": null,
-      "thumb": null
-    },
-    {
-      "version": "11.0.3",
-      "date": "2026-09-01",
-      "headline": "The embedding upgrade ceremony runs on every brain",
-      "items": [
-        "A brain opened through the standard plugin now carries its embedding-model identity, so the full-precision upgrade ceremony can run on it.",
-        "A one-fix release; nothing else changed."
-      ],
-      "url": null,
-      "thumb": null
-    },
-    {
-      "version": "11.0.2",
-      "date": "2026-08-31",
-      "headline": "One embedding quality everywhere, 3–4× faster imports",
-      "items": [
-        "Every runtime embeds with the same full-precision model — search quality no longer depends on where you run.",
-        "Bulk embedding measured 3.1–4.2× faster, and an online re-embed ceremony upgrades existing stores without downtime.",
-        "The engine's change feed is documented, with the SSE/WebSocket fan-out pattern for realtime surfaces."
-      ],
-      "url": null,
-      "thumb": null
-    },
-    {
-      "version": "11.0.1",
-      "date": "2026-08-31",
-      "headline": "Deletes inside transactions are safe",
-      "items": [
-        "Deleting relations inside a transact() no longer corrupts index bookkeeping.",
-        "A store that deletes its last relation keeps serving instead of refusing."
-      ],
-      "url": null,
-      "thumb": null
-    },
-    {
-      "version": "11.0.0",
-      "date": "2026-08-28",
-      "headline": "One install, one engine — Brainy",
-      "items": [
-        "The former two-package pair is one package: the native engine under the familiar API. One import is the whole install.",
-        "A missing native build refuses loudly with its cures named; nothing falls back silently.",
-        "Stores open in place — no migration."
-      ],
-      "url": null,
-      "thumb": null
-    }
-  ],
-  "history": "The version line continues from the 4.3.x native-engine releases; their record lives in the product repository's CHANGELOG.md."
-}
diff --git a/releases/open-brainy.json b/releases/open-brainy.json
deleted file mode 100644
index 9f1cd239..00000000
--- a/releases/open-brainy.json
+++ /dev/null
@@ -1,136 +0,0 @@
-{
-  "product": "open-brainy",
-  "entries": [
-    {
-      "version": "10.4.11",
-      "date": "2026-09-02",
-      "headline": "Hybrid finds filter before they hydrate, one owner per shutdown, and a faster open",
-      "items": [
-        "Hybrid finds (query/vector combined with a filter, including connected and fusion finds) now filter first and hydrate only the page — one batchGet of exactly the requested rows, instead of hydrating everything the search side found. Fixes a bug where any page after the first came back empty.",
-        "A brain now has exactly one shutdown owner — a host and its engine no longer race to close the same store, and a follow-up flush requested during a running flush is handed off cleanly instead of ever risking a stall.",
-        "find({ path }) and other path-scoped VFS searches now serve a real range over the indexed path (O(log n)) instead of refusing the query outright — both scoped and recursive:false searches were silently broken before this.",
-        "Open no longer rescans a brain's whole fact log on every open — sealed segments the manifest already accounts for are skipped, collapsing a multi-second open term to near-zero on large brains.",
-        "commitTransaction() now refuses by name if single-ops are still pending, and a read-only open no longer writes clean-shutdown evidence it didn't earn — two correctness invariants that were previously assumed, not enforced."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.11",
-      "thumb": null
-    },
-    {
-      "version": "10.4.10",
-      "date": "2026-09-02",
-      "headline": "A planner door for indexes, batched containment repair, and a fixed near()",
-      "items": [
-        "An optional planFindPage door lets an index plan a find() and answer it in one call, instead of the engine assembling the plan itself.",
-        "repairContainment's reconcile pass now walks paged edges once instead of issuing one graph call per file.",
-        "find({ near }) now searches around the anchor's own vector and refuses by name when none is available, instead of silently querying with no vector at all."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.10",
-      "thumb": null
-    },
-    {
-      "version": "10.4.9",
-      "date": "2026-09-02",
-      "headline": "Graph-first finds, honest verb arrays, and opens that stop rescanning history",
-      "items": [
-        "find({ connected, where }) now walks the neighbours first and filters only those rows — correct at every page, and O(neighbours) instead of O(store).",
-        "related() with a list of verb types (or sources, or targets) returns every requested kind — four fast paths silently kept only the first.",
-        "Deferred-embedding recovery resumes from a low-water mark instead of rescanning the whole generation log at every open — measured at two minutes on a large brain, now milliseconds."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.9",
-      "thumb": null
-    },
-    {
-      "version": "10.4.7",
-      "date": "2026-09-01",
-      "headline": "Count ledgers can no longer race themselves",
-      "items": [
-        "Concurrent count flushes coalesce into one writer with a trailing pass — parallel flushes can no longer corrupt a store's count ledger.",
-        "Atomic writes carry a per-process sequence, so two processes' temp files can never collide."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.7",
-      "thumb": null
-    },
-    {
-      "version": "10.4.6",
-      "date": "2026-08-31",
-      "headline": "Transactions cross the index seam safely",
-      "items": [
-        "Deleting relations inside a transact() no longer fails against the metadata index — operations take a JSON-safe view at the moment they execute.",
-        "Fixes a class of transaction failures on stores with integer-mapped relation endpoints."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.6",
-      "thumb": null
-    },
-    {
-      "version": "10.4.5",
-      "date": "2026-08-31",
-      "headline": "Recovery tells the truth, docs live at home",
-      "items": [
-        "A torn generation-log tail is a terminal verdict with a named cure — never an endless wait at open.",
-        "A sealed segment declares only the generations it actually holds.",
-        "The engine's documentation now publishes from its own repository."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.5",
-      "thumb": null
-    },
-    {
-      "version": "10.4.4",
-      "date": "2026-08-28",
-      "headline": "Faster opens, quieter idle",
-      "items": [
-        "Opening a store discovers generations from directory names instead of walking the log, and answers \"any entities?\" with one directory read.",
-        "The flush-request watch is event-driven; idle stores stop paying a polling heartbeat.",
-        "A slow open now names the exact step it is in, so operators see what is being paid and why."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.4",
-      "thumb": null
-    },
-    {
-      "version": "10.4.3",
-      "date": "2026-08-27",
-      "headline": "Open Brainy, under its own name",
-      "items": [
-        "The same engine as 10.4.2, now published as @soulcraftlabs/brainy — the MIT reference engine, on The Source.",
-        "No code changes; your imports change once and everything else stays put."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.3",
-      "thumb": null
-    },
-    {
-      "version": "10.4.2",
-      "date": "2026-08-27",
-      "headline": "Vectors that lie are refused, counts that drift are caught",
-      "items": [
-        "A zero-norm vector is not a vector: the index refuses them, rebuilds skip them, and a sanctioned unvector door removes them cleanly.",
-        "The canonical count ledger derives from identity records and marks legacy-derived ledgers suspect at load.",
-        "Plugin activation failures keep their original error as cause, so the real frame reaches your logs."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.2",
-      "thumb": null
-    },
-    {
-      "version": "10.4.1",
-      "date": "2026-08-26",
-      "headline": "Writes that change nothing cost nothing",
-      "items": [
-        "The read gate is per index family, and a write carrying unchanged data never re-embeds.",
-        "The vectored-row count joins the ledger, so vector coverage is a number you can read, not a guess."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.1",
-      "thumb": null
-    },
-    {
-      "version": "10.4.0",
-      "date": "2026-08-26",
-      "headline": "Repair routing, the vector ledger, and honest empties",
-      "items": [
-        "Repairs route to the index that owns the damage, and the open gate closes the vector leg until coverage is proven.",
-        "An empty string is real data, not a missing field.",
-        "The metadata crossing never carries raw integer relation endpoints — a whole class of serialization faults closed."
-      ],
-      "url": "https://source.soulcraft.com/soulcraftlabs/open-brainy/releases/tag/v10.4.0",
-      "thumb": null
-    }
-  ],
-  "history": "Earlier releases are recorded in CHANGELOG.md in this repository."
-}
diff --git a/scripts/release.sh b/scripts/release.sh
index 5d434320..1a4fe575 100755
--- a/scripts/release.sh
+++ b/scripts/release.sh
@@ -237,7 +237,7 @@ fi
 # and RELEASES.md are the record; this just gives The Source's UI a release page).
 echo -e "${BLUE}🔟 Creating release page on The Source...${NC}"
 if [ -n "${FORGEJO_RELEASE_TOKEN:-}" ]; then
-  if curl -sf -X POST "https://source.soulcraft.com/api/v1/repos/soulcraftlabs/open-brainy/releases" \
+  if curl -sf -X POST "https://source.soulcraft.com/api/v1/repos/soulcraft/brainy/releases" \
     -H "Authorization: token ${FORGEJO_RELEASE_TOKEN}" -H "Content-Type: application/json" \
     -d "{\"tag_name\":\"v${NEW_VERSION}\",\"name\":\"v${NEW_VERSION}\",\"prerelease\":${PRERELEASE}}" >/dev/null; then
     echo -e "${GREEN}✅ Release page created on The Source${NC}\n"
diff --git a/src/brainy.ts b/src/brainy.ts
index da04577e..06c947c2 100644
--- a/src/brainy.ts
+++ b/src/brainy.ts
@@ -15,6 +15,7 @@ import { JsHnswVectorIndex } from './hnsw/hnswIndex.js'
 import { createStorage, resolveFilesystemRoot } from './storage/storageFactory.js'
 import type { StorageOptions } from './storage/storageFactory.js'
 import { rebuildCounts } from './utils/rebuildCounts.js'
+import { jsonSafeIndexMetadata } from './utils/jsonSafeIndexMetadata.js'
 import type { MetadataWriteBuffer } from './utils/metadataWriteBuffer.js'
 import { BaseStorage } from './storage/baseStorage.js'
 import {
@@ -4203,32 +4204,19 @@ export class Brainy<T = any> implements BrainyInterface<T> {
    */
   /**
    * @description A JSON-safe view of a record bound for the metadata-index
-   * crossing. The seam's metadata is JSON-safe BY CONTRACT (a native provider
-   * serializes it; u64 ints as Number corrupt above 2^53) — but
-   * {@link resolveVerbEndpointInts} MIRRORS the resolved endpoint ints onto
-   * the verb object itself as BigInt (`verb.sourceInt`/`targetInt`), so a
-   * verb object reused as index metadata carried BigInts into
-   * JSON.stringify, which throws, aborting the whole transaction (found by
-   * the first joint pair gate). Endpoint ints ride their OWN op params on the
-   * graph legs — the metadata crossing drops every BigInt-valued top-level
-   * key instead of guessing at a lossy numeric encoding.
+   * crossing — delegates to the shared {@link jsonSafeIndexMetadata} leaf,
+   * which the metadata-index transaction operations ALSO apply at execute
+   * and rollback time. This plan-time wrap alone proved insufficient: it
+   * returns the same reference when the record is clean, and `transact()`'s
+   * delete legs share that reference with a graph-retraction op whose
+   * execute-time endpoint resolution mirrors BigInt ints onto it (the full
+   * aliasing story lives on the leaf module's doc).
    * @param metadata - The candidate index-metadata record.
    * @returns The same object when already JSON-safe, else a shallow copy
    *   without the BigInt-valued keys.
    */
   private static jsonSafeIndexMetadata(metadata: unknown): unknown {
-    if (metadata === null || typeof metadata !== 'object') return metadata
-    const rec = metadata as Record<string, unknown>
-    let hasBigint = false
-    for (const k in rec) {
-      if (typeof rec[k] === 'bigint') { hasBigint = true; break }
-    }
-    if (!hasBigint) return metadata
-    const out: Record<string, unknown> = {}
-    for (const k in rec) {
-      if (typeof rec[k] !== 'bigint') out[k] = rec[k]
-    }
-    return out
+    return jsonSafeIndexMetadata(metadata)
   }
 
   private metadataIndexRetractionOp(
diff --git a/src/storage/adapters/baseStorageAdapter.ts b/src/storage/adapters/baseStorageAdapter.ts
index cabe2e30..a90adb93 100644
--- a/src/storage/adapters/baseStorageAdapter.ts
+++ b/src/storage/adapters/baseStorageAdapter.ts
@@ -1089,6 +1089,10 @@ export abstract class BaseStorageAdapter implements StorageAdapter {
 
   // Counts changed since the last persist? Drives the write-through flush.
   protected pendingCountPersist = false
+  /** The one persist running right now, if any (single-flight law — see flushCounts). */
+  private countPersistInFlight: Promise<void> | null = null
+  /** The one trailing persist a burst has queued behind the in-flight one. */
+  private countPersistTrailing: Promise<void> | null = null
 
   /**
    * Get total noun count - O(1) operation
@@ -1341,15 +1345,46 @@ export abstract class BaseStorageAdapter implements StorageAdapter {
       return
     }
 
-    try {
-      // Persist to storage (implemented by subclass)
-      await this.persistCounts()
-      this.pendingCountPersist = false
-    } catch (error) {
-      console.error('CRITICAL: Failed to flush counts to storage:', error)
-      // Keep pending flag set so we retry on next operation
-      throw error
+    // SINGLE-FLIGHT, COALESCED. Counts are write-through on every change, so
+    // a burst of writes used to launch one persist per change, all in flight
+    // together. Two of them inside the same millisecond shared the atomic
+    // writer's temp path (`.tmp-<pid>-<ms>`): both wrote it, the first rename
+    // consumed it, the second rename found nothing — ENOENT, ~1,500 times a
+    // day on a busy production brain, with a full ledger write per change
+    // behind it. Now exactly one persist runs at a time; requests that arrive
+    // while it runs collapse into ONE trailing persist that carries the final
+    // state. A burst of N changes costs at most two writes and never races
+    // itself.
+    if (this.countPersistInFlight) {
+      // The in-flight write may have already serialised a stale snapshot —
+      // ask for one more pass after it, and let every caller in this burst
+      // await that same pass.
+      if (!this.countPersistTrailing) {
+        this.countPersistTrailing = this.countPersistInFlight
+          .catch(() => undefined)
+          .then(() => {
+            this.countPersistTrailing = null
+            return this.flushCounts()
+          })
+      }
+      return this.countPersistTrailing
     }
+
+    this.countPersistInFlight = (async () => {
+      try {
+        // Persist to storage (implemented by subclass)
+        this.pendingCountPersist = false
+        await this.persistCounts()
+      } catch (error) {
+        // Keep the flag set so the next operation retries.
+        this.pendingCountPersist = true
+        console.error('CRITICAL: Failed to flush counts to storage:', error)
+        throw error
+      } finally {
+        this.countPersistInFlight = null
+      }
+    })()
+    return this.countPersistInFlight
   }
 
   /**
diff --git a/src/storage/adapters/fileSystemStorage.ts b/src/storage/adapters/fileSystemStorage.ts
index 5ec1d88e..87b6406f 100644
--- a/src/storage/adapters/fileSystemStorage.ts
+++ b/src/storage/adapters/fileSystemStorage.ts
@@ -2400,8 +2400,15 @@ export class FileSystemStorage extends BaseStorage {
    * Atomic write via temp-file-then-rename so concurrent readers never see a
    * half-written lock JSON. Reused by writer-lock writes + heartbeat.
    */
+  /** Monotonic per-process sequence so two atomic writes never share a temp path. */
+  private static atomicWriteSeq = 0
+
   private async writeFileAtomic(filePath: string, contents: string): Promise<void> {
-    const tmp = `${filePath}.tmp-${process.pid}-${Date.now()}`
+    // pid + timestamp alone collided: two writers of the same target inside
+    // one millisecond shared this path, and the loser's rename found the
+    // winner had already moved it (ENOENT). The sequence makes every call's
+    // temp path its own.
+    const tmp = `${filePath}.tmp-${process.pid}-${Date.now()}-${++FileSystemStorage.atomicWriteSeq}`
     await fs.promises.writeFile(tmp, contents)
     await fs.promises.rename(tmp, filePath)
   }
diff --git a/src/transaction/operations/IndexOperations.ts b/src/transaction/operations/IndexOperations.ts
index 1bbbca88..0142dc54 100644
--- a/src/transaction/operations/IndexOperations.ts
+++ b/src/transaction/operations/IndexOperations.ts
@@ -14,6 +14,7 @@ import type { MetadataIndexManager } from '../../utils/metadataIndex.js'
 import type { GraphVerb } from '../../coreTypes.js'
 import type { Operation, RollbackAction } from '../types.js'
 import { isZeroNormVector } from '../../utils/distance.js'
+import { jsonSafeIndexMetadata } from '../../utils/jsonSafeIndexMetadata.js'
 import { prodLog } from '../../utils/logger.js'
 
 /**
@@ -390,13 +391,21 @@ export class AddToMetadataIndexOperation implements Operation {
     // rollback so add + undo reference the same watermark.
     const generation = this.generationFn?.()
 
-    // Add to metadata index (skipFlush=true for transaction atomicity)
-    await this.index.addToIndex(this.id, this.entity, true, false, generation)
+    // The JSON-safe view is taken HERE, per crossing, never at construction:
+    // the entity reference this op holds can be mutated between plan and
+    // execute (a graph op's execute-time endpoint-int resolution mirrors
+    // BigInts onto a shared verb object) — see jsonSafeIndexMetadata's
+    // module doc.
+    await this.index.addToIndex(
+      this.id, jsonSafeIndexMetadata(this.entity), true, false, generation
+    )
 
     // Return rollback action
     return async () => {
       // Remove from metadata index
-      await this.index.removeFromIndex(this.id, this.entity, generation)
+      await this.index.removeFromIndex(
+        this.id, jsonSafeIndexMetadata(this.entity), generation
+      )
     }
   }
 }
@@ -432,13 +441,21 @@ export class RemoveFromMetadataIndexOperation implements Operation {
     // Resolve the removal generation once; reuse it for the rollback re-add.
     const generation = this.generationFn?.()
 
-    // Remove from metadata index
-    await this.index.removeFromIndex(this.id, this.entity, generation)
+    // Sanitized per crossing, never at construction — transact()'s delete
+    // legs hand this op the SAME verb object the graph-retraction op's
+    // execute-time endpoint resolution mutates (BigInt sourceInt/targetInt),
+    // so a plan-time view aliases the pollution. See jsonSafeIndexMetadata's
+    // module doc.
+    await this.index.removeFromIndex(
+      this.id, jsonSafeIndexMetadata(this.entity), generation
+    )
 
     // Return rollback action
     return async () => {
       // Re-add with original metadata (skipFlush=true)
-      await this.index.addToIndex(this.id, this.entity, true, false, generation)
+      await this.index.addToIndex(
+        this.id, jsonSafeIndexMetadata(this.entity), true, false, generation
+      )
     }
   }
 }
diff --git a/src/utils/jsonSafeIndexMetadata.ts b/src/utils/jsonSafeIndexMetadata.ts
new file mode 100644
index 00000000..d3b1be5f
--- /dev/null
+++ b/src/utils/jsonSafeIndexMetadata.ts
@@ -0,0 +1,47 @@
+/**
+ * @module utils/jsonSafeIndexMetadata
+ * @description The metadata-index crossing's JSON-safety law, as a leaf
+ * function both the coordinator and the transaction operations share.
+ *
+ * The seam's metadata is JSON-safe BY CONTRACT (a native provider serializes
+ * it; u64 ints as Number corrupt above 2^53) — but `resolveVerbEndpointInts`
+ * MIRRORS the resolved endpoint ints onto the verb object itself as BigInt
+ * (`verb.sourceInt`/`targetInt`), so a verb object reused as index metadata
+ * carries BigInts into JSON.stringify, which throws, aborting the whole
+ * transaction. Endpoint ints ride their OWN op params on the graph legs — the
+ * metadata crossing drops every BigInt-valued top-level key instead of
+ * guessing at a lossy numeric encoding.
+ *
+ * WHY THIS IS A LEAF MODULE, ENFORCED AT THE CROSSING: sanitizing only at
+ * operation-construction time is not enough. `transact()`'s delete legs pass
+ * the SAME verb object to both the graph-retraction op (whose endpoint-int
+ * thunk deliberately resolves at EXECUTE time, for same-batch forward refs)
+ * and the metadata-retraction op. At plan time the verb is still clean, so a
+ * plan-time sanitize returns the same reference — then the graph op executes
+ * first, mirrors the BigInt ints onto the shared object, and the metadata op
+ * crosses the seam with them (found by the first fleet adoption of the native
+ * pair: every transact-wrapped edge delete aborted). The crossing itself is
+ * the only place ordering cannot bypass.
+ */
+
+/**
+ * A JSON-safe view of a record bound for the metadata-index crossing.
+ *
+ * @param metadata - The candidate index-metadata record.
+ * @returns The same object when already JSON-safe, else a shallow copy
+ *   without the BigInt-valued keys.
+ */
+export function jsonSafeIndexMetadata(metadata: unknown): unknown {
+  if (metadata === null || typeof metadata !== 'object') return metadata
+  const rec = metadata as Record<string, unknown>
+  let hasBigint = false
+  for (const k in rec) {
+    if (typeof rec[k] === 'bigint') { hasBigint = true; break }
+  }
+  if (!hasBigint) return metadata
+  const out: Record<string, unknown> = {}
+  for (const k in rec) {
+    if (typeof rec[k] !== 'bigint') out[k] = rec[k]
+  }
+  return out
+}
diff --git a/tests/integration/counts-persist-single-flight.test.ts b/tests/integration/counts-persist-single-flight.test.ts
new file mode 100644
index 00000000..5acbdcc3
--- /dev/null
+++ b/tests/integration/counts-persist-single-flight.test.ts
@@ -0,0 +1,111 @@
+/**
+ * @module tests/integration/counts-persist-single-flight
+ * @description Regression for a production race in FileSystemStorage's
+ * counts ledger: `persistCounts()` was write-through on every count change
+ * with no serialization, and the atomic writer named its temp file with
+ * millisecond granularity (`.tmp-<pid>-<ms>`). Two persists inside one
+ * millisecond shared the temp path — both wrote it, the first rename
+ * consumed it, the second rename found nothing: ENOENT, ~1,500 times a day
+ * on a busy production brain, with a full ledger write per change behind it.
+ *
+ * Under pin: persists are single-flight and coalesced — one in flight, at
+ * most one trailing pass carrying the burst's final state — and every atomic
+ * write owns a unique temp path. A burst of N count changes costs at most
+ * two ledger writes, never errors, and leaves a ledger equal to memory.
+ */
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
+import * as fs from 'node:fs'
+import * as os from 'node:os'
+import * as path from 'node:path'
+import { Brainy } from '../../src/brainy.js'
+import { NounType } from '../../src/types/graphTypes.js'
+
+describe('counts persistence is single-flight, coalesced, and never races its own temp file', () => {
+  let dir: string
+  let brain: any
+
+  beforeEach(async () => {
+    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
+    dir = fs.mkdtempSync(path.join(os.tmpdir(), 'brainy-counts-race-'))
+    brain = new Brainy({
+      requireSubtype: false,
+      storage: { type: 'filesystem', path: dir },
+      dimensions: 384,
+      silent: true
+    })
+    await brain.init()
+  })
+
+  afterEach(async () => {
+    vi.restoreAllMocks()
+    await brain.close()
+    fs.rmSync(dir, { recursive: true, force: true })
+  })
+
+  it('a burst of concurrent count changes → at most two ledger writes, zero errors, ledger == memory', async () => {
+    const storage = brain.storage
+    const countsPath: string = storage.countsFilePath
+    expect(countsPath, 'the filesystem adapter persists a counts ledger').toBeTruthy()
+
+    // Let init's own persists settle so the burst is measured alone.
+    await storage.flushCounts?.()
+
+    const renameSpy = vi.spyOn(fs.promises, 'rename')
+    const errorSpy = vi.spyOn(console, 'error')
+
+    // Twenty-five concurrent count changes — the shape of a write burst; each
+    // used to launch its own persist.
+    const BURST = 25
+    await Promise.all(
+      Array.from({ length: BURST }, () => storage.scheduleCountPersist())
+    )
+
+    const ledgerRenames = renameSpy.mock.calls.filter(([, to]) => String(to) === countsPath)
+    expect(ledgerRenames.length, 'single-flight + one trailing pass').toBeLessThanOrEqual(2)
+    expect(ledgerRenames.length, 'the burst was persisted at all').toBeGreaterThanOrEqual(1)
+
+    const persistErrors = errorSpy.mock.calls.filter((args) => String(args[0]).includes('persisting counts'))
+    expect(persistErrors).toEqual([])
+
+    const ledger = JSON.parse(fs.readFileSync(countsPath, 'utf-8'))
+    expect(ledger.totalNounCount).toBe(storage.totalNounCount)
+    expect(ledger.totalVerbCount).toBe(storage.totalVerbCount)
+  })
+
+  it('real writes in parallel: the ledger lands complete and no persist error is logged', async () => {
+    const storage = brain.storage
+    const countsPath: string = storage.countsFilePath
+    const errorSpy = vi.spyOn(console, 'error')
+
+    await Promise.all(
+      Array.from({ length: 12 }, (_, i) =>
+        brain.add({ data: `burst row ${i}`, type: NounType.Thing })
+      )
+    )
+    await storage.flushCounts?.()
+
+    const persistErrors = errorSpy.mock.calls.filter((args) => String(args[0]).includes('persisting counts'))
+    expect(persistErrors).toEqual([])
+    const ledger = JSON.parse(fs.readFileSync(countsPath, 'utf-8'))
+    expect(ledger.totalNounCount).toBe(storage.totalNounCount)
+    expect(await brain.getNounCount()).toBe(ledger.totalNounCount)
+  })
+
+  it('every atomic write owns its own temp path — two writes in one millisecond never collide', async () => {
+    const storage = brain.storage
+    const tmpNames: string[] = []
+    vi.spyOn(fs.promises, 'writeFile').mockImplementation(async (p: any) => {
+      tmpNames.push(String(p))
+    })
+    vi.spyOn(fs.promises, 'rename').mockImplementation(async () => undefined)
+    const target = path.join(dir, 'probe.json')
+    await Promise.all([
+      storage.writeFileAtomic(target, '{"a":1}'),
+      storage.writeFileAtomic(target, '{"a":2}'),
+      storage.writeFileAtomic(target, '{"a":3}')
+    ])
+    const probeTmps = tmpNames.filter((n) => n.startsWith(`${target}.tmp-`))
+    expect(probeTmps.length).toBe(3)
+    expect(new Set(probeTmps).size, 'no two writes shared a temp path').toBe(3)
+  })
+})
diff --git a/tests/integration/transact-edge-delete-bigint-aliasing.test.ts b/tests/integration/transact-edge-delete-bigint-aliasing.test.ts
new file mode 100644
index 00000000..b3902571
--- /dev/null
+++ b/tests/integration/transact-edge-delete-bigint-aliasing.test.ts
@@ -0,0 +1,184 @@
+/**
+ * @module tests/integration/transact-edge-delete-bigint-aliasing
+ * @description Regression for a fleet-adoption blocker: ANY edge delete
+ * inside `transact()` — a direct unrelate or a noun-remove's cascade —
+ * aborted with the metadata seam's BigInt JSON-guard error on a strict
+ * (native) metadata provider.
+ *
+ * The aliasing chain: `planTxUnrelate`/the remove-cascade pass the SAME verb
+ * object to the graph-retraction op and the metadata-retraction op. The
+ * metadata leg's JSON-safe wrap ran at PLAN time, when the verb was still
+ * clean — so it returned the same reference. At EXECUTE time the graph op
+ * runs first and `resolveVerbEndpointInts` mirrors BigInt
+ * `sourceInt`/`targetInt` onto the shared object (deliberately deferred for
+ * same-batch forward refs — see transact-forward-ref-graph.test.ts); the
+ * metadata op then crossed the seam with the polluted object. Direct
+ * `unrelate()` resolves ints at BUILD time, before its sanitize, which is why
+ * only the transact() shapes ever hit it.
+ *
+ * Fix under pin: the JSON-safe view is taken AT THE CROSSING — inside the
+ * metadata-index operations' execute/rollback — so no plan-vs-execute
+ * ordering can bypass it. The JS baseline index tolerates BigInts (it would
+ * mask the bug), so these pins SPY on the seam and assert what actually
+ * crossed, exactly as a strict native provider would judge it.
+ */
+import { describe, it, expect, beforeEach, afterEach } from 'vitest'
+import * as fs from 'node:fs'
+import * as os from 'node:os'
+import * as path from 'node:path'
+import { Brainy } from '../../src/brainy.js'
+import { NounType, VerbType } from '../../src/types/graphTypes.js'
+import {
+  AddToMetadataIndexOperation,
+  RemoveFromMetadataIndexOperation
+} from '../../src/transaction/operations/index.js'
+
+let seq = 0
+const freshId = (): string =>
+  `00000000-0000-4000-8000-${(++seq).toString(16).padStart(12, '0')}`
+
+/** Top-level BigInt-valued keys of a candidate seam crossing (the guard's law). */
+const bigintKeys = (metadata: unknown): string[] => {
+  if (metadata === null || typeof metadata !== 'object') return []
+  return Object.entries(metadata as Record<string, unknown>)
+    .filter(([, v]) => typeof v === 'bigint')
+    .map(([k]) => k)
+}
+
+describe('transact() edge deletes never carry BigInt across the metadata seam', () => {
+  let dir: string
+  let brain: any
+  let crossings: Array<{ door: string; id: string; keys: string[] }>
+
+  beforeEach(async () => {
+    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
+    dir = fs.mkdtempSync(path.join(os.tmpdir(), 'brainy-tx-bigint-'))
+    brain = new Brainy({
+      requireSubtype: false,
+      storage: { type: 'filesystem', path: dir },
+      dimensions: 384,
+      silent: true
+    })
+    await brain.init()
+
+    // Spy on the seam the way a strict native provider judges it: record the
+    // BigInt-valued top-level keys of every metadata argument that crosses.
+    // The JS baseline index tolerates BigInts, so without this the baseline
+    // run would green a shape the native pair aborts on.
+    crossings = []
+    const index = brain.metadataIndex
+    for (const door of ['addToIndex', 'removeFromIndex'] as const) {
+      const real = index[door].bind(index)
+      index[door] = (id: string, metadata: unknown, ...rest: unknown[]) => {
+        crossings.push({ door, id, keys: bigintKeys(metadata) })
+        return real(id, metadata, ...rest)
+      }
+    }
+  })
+
+  afterEach(async () => {
+    await brain.close()
+    fs.rmSync(dir, { recursive: true, force: true })
+  })
+
+  it('CASE 1 (the fleet repro): relate, then transact([{op: unrelate}])', async () => {
+    const a = await brain.add({ id: freshId(), data: 'a', type: NounType.Thing })
+    const b = await brain.add({ id: freshId(), data: 'b', type: NounType.Thing })
+    const verbId = await brain.relate({ from: a, to: b, type: VerbType.RelatedTo })
+
+    crossings.length = 0
+    await brain.transact([{ op: 'unrelate', id: verbId }])
+
+    const polluted = crossings.filter((c) => c.keys.length > 0)
+    expect(polluted).toEqual([])
+    expect(await brain.storage.getVerb(verbId)).toBeFalsy()
+  })
+
+  it('CASE 2 (the cascade shape): transact([{op: remove}]) cascading edge deletes', async () => {
+    const a = await brain.add({ id: freshId(), data: 'a', type: NounType.Thing })
+    const b = await brain.add({ id: freshId(), data: 'b', type: NounType.Thing })
+    const c = await brain.add({ id: freshId(), data: 'c', type: NounType.Thing })
+    const ab = await brain.relate({ from: a, to: b, type: VerbType.RelatedTo })
+    const ca = await brain.relate({ from: c, to: a, type: VerbType.RelatedTo })
+
+    crossings.length = 0
+    await brain.transact([{ op: 'remove', id: a }])
+
+    const polluted = crossings.filter((c2) => c2.keys.length > 0)
+    expect(polluted).toEqual([])
+    expect(await brain.get(a)).toBeFalsy()
+    expect(await brain.storage.getVerb(ab)).toBeFalsy()
+    expect(await brain.storage.getVerb(ca)).toBeFalsy()
+  })
+
+  it('CASE 3 (one batch, both legs): adds + relate + unrelate of a pre-existing edge', async () => {
+    const a = await brain.add({ id: freshId(), data: 'a', type: NounType.Thing })
+    const b = await brain.add({ id: freshId(), data: 'b', type: NounType.Thing })
+    const old = await brain.relate({ from: a, to: b, type: VerbType.RelatedTo })
+
+    const x = freshId()
+    crossings.length = 0
+    await brain.transact([
+      { op: 'add', id: x, data: 'x', type: NounType.Thing },
+      { op: 'relate', from: a, to: x, type: VerbType.RelatedTo },
+      { op: 'unrelate', id: old }
+    ])
+
+    const polluted = crossings.filter((c) => c.keys.length > 0)
+    expect(polluted).toEqual([])
+    expect(await brain.storage.getVerb(old)).toBeFalsy()
+    const edges = await brain.related({ from: a })
+    expect(edges.length).toBe(1)
+    expect(edges[0].id).not.toBe(old)
+  })
+})
+
+describe('the metadata-index operations sanitize at the crossing, not at construction', () => {
+  /** A strict seam: refuses BigInts exactly as the native provider does. */
+  const strictIndex = () => {
+    const seen: Array<{ door: string; keys: string[] }> = []
+    const judge = (door: string, metadata: unknown) => {
+      const keys = bigintKeys(metadata)
+      seen.push({ door, keys })
+      if (keys.length > 0) {
+        throw new Error(
+          `${door}: the metadata object violates the provider seam's JSON ` +
+            `contract — BigInt at ${keys.join(', ')}.`
+        )
+      }
+    }
+    return {
+      seen,
+      addToIndex: async (_id: string, metadata: unknown) => judge('addToIndex', metadata),
+      removeFromIndex: async (_id: string, metadata: unknown) => judge('removeFromIndex', metadata)
+    }
+  }
+
+  it('RemoveFromMetadataIndexOperation: entity mutated AFTER construction still crosses clean', async () => {
+    const index = strictIndex()
+    const verb: Record<string, unknown> = { id: 'v1', sourceId: 'a', targetId: 'b' }
+    const op = new RemoveFromMetadataIndexOperation(index as any, 'v1', verb, () => 7n)
+
+    // The graph leg's execute-time endpoint resolution, simulated: the shared
+    // object is polluted between plan and execute.
+    verb.sourceInt = 800_000n
+    verb.targetInt = 800_001n
+
+    const rollback = await op.execute()
+    await rollback()
+    expect(index.seen.map((s) => s.keys)).toEqual([[], []])
+  })
+
+  it('AddToMetadataIndexOperation: same law on the add leg and its rollback', async () => {
+    const index = strictIndex()
+    const verb: Record<string, unknown> = { id: 'v2', sourceId: 'a', targetId: 'b' }
+    const op = new AddToMetadataIndexOperation(index as any, 'v2', verb, () => 7n)
+
+    verb.sourceInt = 800_000n
+    verb.targetInt = 800_001n
+
+    const rollback = await op.execute()
+    await rollback()
+    expect(index.seen.map((s) => s.keys)).toEqual([[], []])
+  })
+})