diff --git a/packages/cloud-connection/src/marketplace-install-local-seed-lookup.test.ts b/packages/cloud-connection/src/marketplace-install-local-seed-lookup.test.ts
index 8030616180..2a9bbf94f7 100644
--- a/packages/cloud-connection/src/marketplace-install-local-seed-lookup.test.ts
+++ b/packages/cloud-connection/src/marketplace-install-local-seed-lookup.test.ts
@@ -83,7 +83,7 @@ function makeEngine() {
             let records = store[objectName] || [];
             if (query?.where) {
                 records = records.filter((r) =>
-                    Object.entries(query.where).every(([k, v]) => r[k] === v),
+                    Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
                 );
             }
             if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/cloud-connection/src/marketplace-install-local-state-machine-exempt.test.ts b/packages/cloud-connection/src/marketplace-install-local-state-machine-exempt.test.ts
index f31d232e7d..463a68f2ee 100644
--- a/packages/cloud-connection/src/marketplace-install-local-state-machine-exempt.test.ts
+++ b/packages/cloud-connection/src/marketplace-install-local-state-machine-exempt.test.ts
@@ -102,7 +102,7 @@ function makeEngine() {
             let records = store[objectName] || [];
             if (query?.where) {
                 records = records.filter((r) =>
-                    Object.entries(query.where).every(([k, v]) => r[k] === v),
+                    Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
                 );
             }
             if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/core/src/security/api-key.test.ts b/packages/core/src/security/api-key.test.ts
index 2689e2a31f..83063853be 100644
--- a/packages/core/src/security/api-key.test.ts
+++ b/packages/core/src/security/api-key.test.ts
@@ -17,7 +17,7 @@ function makeQl(rows: any[]) {
     find: async (object: string, opts: any) => {
       if (object !== 'sys_api_key') return [];
       const where = opts?.where ?? {};
-      return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return rows.filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
   };
 }
diff --git a/packages/core/src/security/resolve-authz-context.test.ts b/packages/core/src/security/resolve-authz-context.test.ts
index ffee6d90e3..82f672c585 100644
--- a/packages/core/src/security/resolve-authz-context.test.ts
+++ b/packages/core/src/security/resolve-authz-context.test.ts
@@ -19,7 +19,7 @@ function makeQl(tables: Record<string, any[]>) {
       const rows = tables[object] ?? [];
       const where = opts?.where ?? {};
       return rows.filter((r) =>
-        Object.entries(where).every(([k, v]) => {
+        Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); 
           if (v && typeof v === 'object' && '$in' in (v as any)) return (v as any).$in.includes(r[k]);
           return r[k] === v;
         }),
@@ -123,7 +123,7 @@ function makeCountingQl(tables: Record<string, any[]>) {
       const rows = tables[object] ?? [];
       const where = opts?.where ?? {};
       return rows.filter((r) =>
-        Object.entries(where).every(([k, v]) => {
+        Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); 
           if (v && typeof v === 'object' && '$in' in (v as any)) return (v as any).$in.includes(r[k]);
           return r[k] === v;
         }),
diff --git a/packages/core/src/utils/migration-journal.test.ts b/packages/core/src/utils/migration-journal.test.ts
index 3302fe8315..bfc0839703 100644
--- a/packages/core/src/utils/migration-journal.test.ts
+++ b/packages/core/src/utils/migration-journal.test.ts
@@ -81,7 +81,7 @@ class FakeEngine {
 
   async find(objectName: string, query?: { where?: Record<string, unknown> }): Promise<FakeRow[]> {
     const where = query?.where ?? {};
-    return this.rows(objectName).filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+    return this.rows(objectName).filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
   }
 
   async findOne(objectName: string, query?: { where?: Record<string, unknown> }): Promise<FakeRow | null> {
diff --git a/packages/metadata-protocol/src/migrations/recorded-by-sentinel.test.ts b/packages/metadata-protocol/src/migrations/recorded-by-sentinel.test.ts
index ed2839058e..cf042f02db 100644
--- a/packages/metadata-protocol/src/migrations/recorded-by-sentinel.test.ts
+++ b/packages/metadata-protocol/src/migrations/recorded-by-sentinel.test.ts
@@ -73,7 +73,7 @@ class FakeEngine {
 
   async find(objectName: string, query?: { where?: Record<string, unknown> }): Promise<FakeRow[]> {
     const where = query?.where ?? {};
-    return this.rows(objectName).filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+    return this.rows(objectName).filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
   }
 
   async findOne(objectName: string, query?: { where?: Record<string, unknown> }): Promise<FakeRow | null> {
diff --git a/packages/metadata-protocol/src/seed-loader-composite-external-id.test.ts b/packages/metadata-protocol/src/seed-loader-composite-external-id.test.ts
index a93a85e32e..97bdc93b96 100644
--- a/packages/metadata-protocol/src/seed-loader-composite-external-id.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-composite-external-id.test.ts
@@ -35,7 +35,7 @@ function createFaithfulEngine(): { engine: IDataEngine; store: Record<string, an
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/metadata-protocol/src/seed-loader-deferred-dropped.test.ts b/packages/metadata-protocol/src/seed-loader-deferred-dropped.test.ts
index eab51637cf..c9fe2e1fe9 100644
--- a/packages/metadata-protocol/src/seed-loader-deferred-dropped.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-deferred-dropped.test.ts
@@ -44,7 +44,7 @@ function createFaithfulEngine(): { engine: IDataEngine; store: Record<string, an
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/metadata-protocol/src/seed-loader-deferred-failure.test.ts b/packages/metadata-protocol/src/seed-loader-deferred-failure.test.ts
index 8e03efcd2b..15c3cd3921 100644
--- a/packages/metadata-protocol/src/seed-loader-deferred-failure.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-deferred-failure.test.ts
@@ -29,7 +29,7 @@ function createFaithfulEngine(): { engine: IDataEngine; store: Record<string, an
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/metadata-protocol/src/seed-loader-driver-text.test.ts b/packages/metadata-protocol/src/seed-loader-driver-text.test.ts
index a684437fc9..8bfc33cae6 100644
--- a/packages/metadata-protocol/src/seed-loader-driver-text.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-driver-text.test.ts
@@ -210,7 +210,7 @@ describe('[#8442] raw driver text is withheld from the seed `errors[].message`',
             find: vi.fn(async (o: string, q?: any) => {
                 const rows = store[o] || [];
                 return q?.where
-                    ? rows.filter((r) => Object.entries(q.where).every(([k, v]) => r[k] === v))
+                    ? rows.filter((r) => Object.entries(q.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }))
                     : rows;
             }),
             findOne: vi.fn(async (o: string, q?: any) => {
diff --git a/packages/metadata-protocol/src/seed-loader-engine-schema-fallback.test.ts b/packages/metadata-protocol/src/seed-loader-engine-schema-fallback.test.ts
index 88ef318475..24d8055685 100644
--- a/packages/metadata-protocol/src/seed-loader-engine-schema-fallback.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-engine-schema-fallback.test.ts
@@ -39,7 +39,7 @@ function createFaithfulEngine(schemas: Record<string, any>) {
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') {
diff --git a/packages/metadata-protocol/src/seed-loader-env-scope.test.ts b/packages/metadata-protocol/src/seed-loader-env-scope.test.ts
index 5856c7a2dd..de107db946 100644
--- a/packages/metadata-protocol/src/seed-loader-env-scope.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-env-scope.test.ts
@@ -43,7 +43,7 @@ function createEngine() {
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/metadata-protocol/src/seed-loader-multi-value-reference.test.ts b/packages/metadata-protocol/src/seed-loader-multi-value-reference.test.ts
index 8dd853789e..3f1690403a 100644
--- a/packages/metadata-protocol/src/seed-loader-multi-value-reference.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-multi-value-reference.test.ts
@@ -36,7 +36,7 @@ function createEngine(schemas: Record<string, any>) {
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/metadata-protocol/src/seed-loader-replay.test.ts b/packages/metadata-protocol/src/seed-loader-replay.test.ts
index d1b5598358..4b72352e97 100644
--- a/packages/metadata-protocol/src/seed-loader-replay.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-replay.test.ts
@@ -30,7 +30,7 @@ function createFaithfulEngine(): { engine: IDataEngine; store: Record<string, an
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') {
diff --git a/packages/metadata-protocol/src/seed-loader-retry.test.ts b/packages/metadata-protocol/src/seed-loader-retry.test.ts
index d57670755a..0a0241cd1c 100644
--- a/packages/metadata-protocol/src/seed-loader-retry.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-retry.test.ts
@@ -25,7 +25,7 @@ function createFaithfulEngine(): { engine: IDataEngine; store: Record<string, an
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/metadata-protocol/src/seed-loader-state-machine-exempt.test.ts b/packages/metadata-protocol/src/seed-loader-state-machine-exempt.test.ts
index ab6d161c19..bec578f618 100644
--- a/packages/metadata-protocol/src/seed-loader-state-machine-exempt.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-state-machine-exempt.test.ts
@@ -68,7 +68,7 @@ function createEnforcingEngine(): { engine: IDataEngine; store: Record<string, a
     find: vi.fn(async (objectName: string, query?: any) => {
       let rows = store[objectName] || [];
       if (query?.where) {
-        rows = rows.filter((r) => Object.entries(query.where).every(([k, v]) => r[k] === v));
+        rows = rows.filter((r) => Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
       }
       if (typeof query?.limit === 'number') rows = rows.slice(0, query.limit);
       return rows;
diff --git a/packages/metadata-protocol/src/seed-loader-summary-stale.test.ts b/packages/metadata-protocol/src/seed-loader-summary-stale.test.ts
index 3f714dabc5..52c00f830a 100644
--- a/packages/metadata-protocol/src/seed-loader-summary-stale.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-summary-stale.test.ts
@@ -37,7 +37,7 @@ function createFaithfulEngine(): { engine: IDataEngine; store: Record<string, an
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/metadata-protocol/src/seed-loader-unresolved-drop.test.ts b/packages/metadata-protocol/src/seed-loader-unresolved-drop.test.ts
index 363a02531b..0854b0367a 100644
--- a/packages/metadata-protocol/src/seed-loader-unresolved-drop.test.ts
+++ b/packages/metadata-protocol/src/seed-loader-unresolved-drop.test.ts
@@ -48,7 +48,7 @@ function createFaithfulEngine(): { engine: IDataEngine; store: Record<string, an
       let records = store[objectName] || [];
       if (query?.where) {
         records = records.filter((r) =>
-          Object.entries(query.where).every(([k, v]) => r[k] === v),
+          Object.entries(query.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
         );
       }
       if (typeof query?.limit === 'number') records = records.slice(0, query.limit);
diff --git a/packages/plugins/plugin-audit/src/comment-access-hooks.test.ts b/packages/plugins/plugin-audit/src/comment-access-hooks.test.ts
index 0cd47d87c3..a62076fcff 100644
--- a/packages/plugins/plugin-audit/src/comment-access-hooks.test.ts
+++ b/packages/plugins/plugin-audit/src/comment-access-hooks.test.ts
@@ -22,13 +22,13 @@ function install(opts: {
     },
     find: async (_object, options: any) => {
       const rows = (opts.comments ?? []).filter((r) =>
-        Object.entries(options?.where ?? {}).every(([k, v]) => r[k] === v),
+        Object.entries(options?.where ?? {}).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
       );
       return typeof options?.limit === 'number' ? rows.slice(0, options.limit) : rows;
     },
     findOne: async (_object, options: any) =>
       (opts.comments ?? []).find((r) =>
-        Object.entries(options?.where ?? {}).every(([k, v]) => r[k] === v),
+        Object.entries(options?.where ?? {}).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
       ) ?? null,
   };
   installCommentAccessHooks(engine, () => opts.sharing, silentLogger());
diff --git a/packages/plugins/plugin-auth/src/account-issuer-parity.test.ts b/packages/plugins/plugin-auth/src/account-issuer-parity.test.ts
index 788cf066e6..bf14392cb8 100644
--- a/packages/plugins/plugin-auth/src/account-issuer-parity.test.ts
+++ b/packages/plugins/plugin-auth/src/account-issuer-parity.test.ts
@@ -81,7 +81,7 @@ function makeQl(row: Record<string, any>) {
       const where = query?.where ?? {};
       return (tables[object] ?? []).filter((r) =>
         Object.entries(where).every(([field, value]) =>
-          value === null ? r[field] == null : r[field] === value,
+          { if (field.startsWith('$')) throw new Error(`fake driver: unsupported operator ${field}`); return value === null ? r[field] == null : r[field] === value; },
         ),
       );
     },
diff --git a/packages/plugins/plugin-auth/src/admin-import-users.test.ts b/packages/plugins/plugin-auth/src/admin-import-users.test.ts
index 580d5e9369..74d50286e9 100644
--- a/packages/plugins/plugin-auth/src/admin-import-users.test.ts
+++ b/packages/plugins/plugin-auth/src/admin-import-users.test.ts
@@ -33,7 +33,7 @@ function makeDeps(opts: {
   });
   const find = vi.fn(async (_obj: string, q: any) => {
     const where = q?.where ?? {};
-    return existing.filter((u) => Object.entries(where).every(([k, v]) => u[k] === v));
+    return existing.filter((u) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return u[k] === v; }));
   });
   const update = vi.fn(async () => ({}));
   const insert = vi.fn(async () => ({}));
diff --git a/packages/plugins/plugin-auth/src/auth-manager.test.ts b/packages/plugins/plugin-auth/src/auth-manager.test.ts
index c8b090952c..3f6db9b0ae 100644
--- a/packages/plugins/plugin-auth/src/auth-manager.test.ts
+++ b/packages/plugins/plugin-auth/src/auth-manager.test.ts
@@ -3862,7 +3862,7 @@ describe('isOrgOrPlatformAdmin – one grade ruler for "is this membership an ad
       if (object === 'sys_member') {
         const where = query?.where ?? {};
         return (opts.members ?? []).filter((row) =>
-          Object.entries(where).every(([k, v]) => row[k] === v),
+          Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return row[k] === v; }),
         );
       }
       return [];
diff --git a/packages/plugins/plugin-auth/src/backfill-account-issuer.test.ts b/packages/plugins/plugin-auth/src/backfill-account-issuer.test.ts
index fe8504fb27..7679bc9af0 100644
--- a/packages/plugins/plugin-auth/src/backfill-account-issuer.test.ts
+++ b/packages/plugins/plugin-auth/src/backfill-account-issuer.test.ts
@@ -26,7 +26,7 @@ function makeQl(tables: Record<string, any[]>) {
       const where = query?.where ?? {};
       return rows.filter((row) =>
         Object.entries(where).every(([field, value]) =>
-          value === null ? row[field] == null : row[field] === value,
+          { if (field.startsWith('$')) throw new Error(`fake driver: unsupported operator ${field}`); return value === null ? row[field] == null : row[field] === value; },
         ),
       );
     }),
diff --git a/packages/plugins/plugin-email/src/attachment-reclaim.test.ts b/packages/plugins/plugin-email/src/attachment-reclaim.test.ts
index 10803bb811..a2408df0c8 100644
--- a/packages/plugins/plugin-email/src/attachment-reclaim.test.ts
+++ b/packages/plugins/plugin-email/src/attachment-reclaim.test.ts
@@ -55,7 +55,7 @@ function fakeEngine(rows: Array<Record<string, any>>) {
     updates: [] as Array<Record<string, any>>,
     async find(table: string, o: any = {}) {
       const where = o?.where ?? {};
-      let out = rowsOf(table).filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      let out = rowsOf(table).filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
       if (o.limit) out = out.slice(0, o.limit);
       return out;
     },
@@ -73,7 +73,11 @@ function fakeEngine(rows: Array<Record<string, any>>) {
       const dispatch = assertEngineDeleteDispatch(o);
       if (dispatch.kind === 'multi') {
         const survivors = rowsOf(table).filter(
-          (r) => !Object.entries(o?.where ?? {}).every(([k, v]) => r[k] === v),
+          (r) =>
+            !Object.entries(o?.where ?? {}).every(([k, v]) => {
+              if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`);
+              return r[k] === v;
+            }),
         );
         const deleted = rowsOf(table).length - survivors.length;
         tables.set(table, survivors);
diff --git a/packages/plugins/plugin-security/src/bootstrap-declared-capabilities.test.ts b/packages/plugins/plugin-security/src/bootstrap-declared-capabilities.test.ts
index e863ec64d0..8b90c57fbe 100644
--- a/packages/plugins/plugin-security/src/bootstrap-declared-capabilities.test.ts
+++ b/packages/plugins/plugin-security/src/bootstrap-declared-capabilities.test.ts
@@ -30,7 +30,7 @@ function makeQl(declared: any[] = []) {
       // `organization_id: null`, which strict `===` would make unsatisfiable
       // here while it works in production.
       return rows.filter((r) =>
-        Object.entries(where).every(([k, v]) => (v === null ? r[k] == null : r[k] === v)),
+        Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return (v === null ? r[k] == null : r[k] === v); }),
       );
     },
     async insert(object: string, data: any) {
diff --git a/packages/plugins/plugin-security/src/bootstrap-declared-permissions.test.ts b/packages/plugins/plugin-security/src/bootstrap-declared-permissions.test.ts
index 4b94c6fbdf..2ae1b613cd 100644
--- a/packages/plugins/plugin-security/src/bootstrap-declared-permissions.test.ts
+++ b/packages/plugins/plugin-security/src/bootstrap-declared-permissions.test.ts
@@ -15,7 +15,7 @@ function makeQl(declared: any[] = []) {
     async find(object: string, q: any) {
       if (object !== 'sys_permission_set') return [];
       const where = q?.where ?? {};
-      return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return rows.filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
     async insert(object: string, data: any) {
       if (object !== 'sys_permission_set') return null;
diff --git a/packages/plugins/plugin-security/src/bootstrap-declared-positions.test.ts b/packages/plugins/plugin-security/src/bootstrap-declared-positions.test.ts
index d5c39469eb..2bd7bb626b 100644
--- a/packages/plugins/plugin-security/src/bootstrap-declared-positions.test.ts
+++ b/packages/plugins/plugin-security/src/bootstrap-declared-positions.test.ts
@@ -26,7 +26,7 @@ function makeQl(declared: any[] = []) {
     async find(object: string, q: any) {
       if (object !== 'sys_position') return [];
       const where = q?.where ?? {};
-      return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return rows.filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
     async insert(object: string, data: any) {
       if (object !== 'sys_position') return null;
diff --git a/packages/plugins/plugin-security/src/bootstrap-platform-admin.test.ts b/packages/plugins/plugin-security/src/bootstrap-platform-admin.test.ts
index 1905575d86..9701a38b88 100644
--- a/packages/plugins/plugin-security/src/bootstrap-platform-admin.test.ts
+++ b/packages/plugins/plugin-security/src/bootstrap-platform-admin.test.ts
@@ -27,7 +27,7 @@ function makeQl(seedRows: any[] = []) {
     async find(object: string, q: any) {
       if (object !== 'sys_permission_set') return [];
       const where = q?.where ?? {};
-      return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return rows.filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
     async insert(object: string, data: any) {
       if (object !== 'sys_permission_set') return null;
diff --git a/packages/plugins/plugin-security/src/bootstrap-system-capabilities.test.ts b/packages/plugins/plugin-security/src/bootstrap-system-capabilities.test.ts
index c8f8c36a35..e4563a5b8a 100644
--- a/packages/plugins/plugin-security/src/bootstrap-system-capabilities.test.ts
+++ b/packages/plugins/plugin-security/src/bootstrap-system-capabilities.test.ts
@@ -47,7 +47,7 @@ function makeQl() {
       const where = q?.where ?? {};
       const matched = rows.filter((r) =>
         // (2) `null` is IS NULL, not `=== null`.
-        Object.entries(where).every(([k, v]) => (v === null ? r[k] == null : r[k] === v)),
+        Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return (v === null ? r[k] == null : r[k] === v); }),
       );
       if (q?.limit === undefined) return matched;
       // (1) The #4363 tie-breaker. BINARY collation, as SQLite compares ids.
diff --git a/packages/plugins/plugin-security/src/explain-engine.test.ts b/packages/plugins/plugin-security/src/explain-engine.test.ts
index 306b7436cb..5dd3b982b7 100644
--- a/packages/plugins/plugin-security/src/explain-engine.test.ts
+++ b/packages/plugins/plugin-security/src/explain-engine.test.ts
@@ -444,7 +444,7 @@ function makeGrantQl(tables: Rows) {
     async find(object: string, opts: any) {
       const where = opts?.where ?? {};
       return (tables[object] ?? []).filter((row) =>
-        Object.entries(where).every(([key, cond]) => {
+        Object.entries(where).every(([key, cond]) => { if (key.startsWith('$')) throw new Error(`fake driver: unsupported operator ${key}`); 
           const cell = row[key];
           if (cond && typeof cond === 'object' && '$in' in (cond as any)) {
             return ((cond as any).$in as unknown[]).includes(cell);
diff --git a/packages/plugins/plugin-security/src/invitation-placement.test.ts b/packages/plugins/plugin-security/src/invitation-placement.test.ts
index b9119aa464..c38c21dc37 100644
--- a/packages/plugins/plugin-security/src/invitation-placement.test.ts
+++ b/packages/plugins/plugin-security/src/invitation-placement.test.ts
@@ -32,9 +32,9 @@ function makeQl(tables: Record<string, any[]> = {}) {
       const where = opts?.where ?? {};
       return rows.filter((row) =>
         Object.entries(where).every(([k, v]) =>
-          v && typeof v === 'object' && '$in' in (v as any)
+          { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return v && typeof v === 'object' && '$in' in (v as any)
             ? (v as any).$in.includes(row[k])
-            : row[k] === v,
+            : row[k] === v; },
         ),
       );
     }),
diff --git a/packages/plugins/plugin-security/src/normalize-managed-by.test.ts b/packages/plugins/plugin-security/src/normalize-managed-by.test.ts
index 17a86b3949..502b878cc2 100644
--- a/packages/plugins/plugin-security/src/normalize-managed-by.test.ts
+++ b/packages/plugins/plugin-security/src/normalize-managed-by.test.ts
@@ -17,7 +17,7 @@ function makeQl() {
     async find(object: string, opts: any) {
       const where = opts?.where ?? {};
       return (tables[object] ?? []).filter((r) =>
-        Object.entries(where).every(([k, v]) => r[k] === v),
+        Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
       );
     },
     async update(object: string, data: any) {
diff --git a/packages/plugins/plugin-webhooks/src/auto-enqueuer.test.ts b/packages/plugins/plugin-webhooks/src/auto-enqueuer.test.ts
index fdfb10df21..2f005fb206 100644
--- a/packages/plugins/plugin-webhooks/src/auto-enqueuer.test.ts
+++ b/packages/plugins/plugin-webhooks/src/auto-enqueuer.test.ts
@@ -81,7 +81,7 @@ class FakeEngine implements IDataEngine {
     async find(name: string, q?: any): Promise<any[]> {
         const all = this.rows[name] ?? [];
         if (!q?.where) return all;
-        return all.filter((r) => Object.entries(q.where).every(([k, v]) => r[k] === v));
+        return all.filter((r) => Object.entries(q.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     }
     async findOne(name: string, q?: any): Promise<any> {
         return (await this.find(name, q))[0] ?? null;
@@ -104,7 +104,14 @@ class FakeEngine implements IDataEngine {
         const arr = this.rows[name] ?? [];
         const before = arr.length;
         this.rows[name] = arr.filter(
-            (r) => !(opts?.where && Object.entries(opts.where).every(([k, v]) => r[k] === v)),
+            (r) =>
+                !(
+                    opts?.where &&
+                    Object.entries(opts.where).every(([k, v]) => {
+                        if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`);
+                        return r[k] === v;
+                    })
+                ),
         );
         return { affected: before - this.rows[name].length };
     }
diff --git a/packages/rest/src/import-runner-idempotency.test.ts b/packages/rest/src/import-runner-idempotency.test.ts
index 37935807c5..000414bd9c 100644
--- a/packages/rest/src/import-runner-idempotency.test.ts
+++ b/packages/rest/src/import-runner-idempotency.test.ts
@@ -53,7 +53,7 @@ function makeProtocol(opts: { firstCall?: 'throw' | 'shortReturn' } = {}) {
     const filter = args.query?.$filter ?? {};
     // Supports equality and { $in: [...] } — the id recheck (framework#3173)
     // queries by pre-assigned id $in, like the real SQL driver does.
-    return store.filter((row) => Object.entries(filter).every(([k, v]) => {
+    return store.filter((row) => Object.entries(filter).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); 
       if (v && typeof v === 'object' && Array.isArray((v as any).$in)) return (v as any).$in.includes(row[k]);
       return row[k] === v;
     }));
diff --git a/packages/rest/src/import-runner-selfref.test.ts b/packages/rest/src/import-runner-selfref.test.ts
index 710f6249d1..1ac369e2ae 100644
--- a/packages/rest/src/import-runner-selfref.test.ts
+++ b/packages/rest/src/import-runner-selfref.test.ts
@@ -44,7 +44,7 @@ function makeProtocol(seed: Array<Record<string, any>> = []) {
   }));
   const findData = vi.fn(async (args: { query?: { $filter?: Record<string, any> } }) => {
     const filter = args.query?.$filter ?? {};
-    return store.filter((row) => Object.entries(filter).every(([k, v]) => row[k] === v));
+    return store.filter((row) => Object.entries(filter).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return row[k] === v; }));
   });
   const p: ImportProtocolLike = { findData, createData: vi.fn(), updateData: vi.fn(), createManyData };
   return { p, store, createManyData };
diff --git a/packages/runtime/src/http-dispatcher.keys.test.ts b/packages/runtime/src/http-dispatcher.keys.test.ts
index 5bdb21767b..3fe150b6be 100644
--- a/packages/runtime/src/http-dispatcher.keys.test.ts
+++ b/packages/runtime/src/http-dispatcher.keys.test.ts
@@ -25,7 +25,7 @@ function makeKernel() {
     find: async (obj: string, opts: any) => {
       const where = opts?.where ?? {};
       if (obj !== 'sys_api_key') return [];
-      return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return rows.filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
     update: async () => ({}),
     delete: async () => ({}),
diff --git a/packages/runtime/src/http-dispatcher.test.ts b/packages/runtime/src/http-dispatcher.test.ts
index d49e7e829e..d43c662d0d 100644
--- a/packages/runtime/src/http-dispatcher.test.ts
+++ b/packages/runtime/src/http-dispatcher.test.ts
@@ -3944,7 +3944,7 @@ describe('HttpDispatcher — action body ctx.user identity (#2701)', () => {
       find: async (obj: string, opts: any) => {
         const where = opts?.where ?? {};
         if (obj !== 'sys_api_key') return [];
-        return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+        return rows.filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
       },
       update: async () => ({}), delete: async () => ({}),
     };
diff --git a/packages/runtime/src/migration-recovery-plugin.test.ts b/packages/runtime/src/migration-recovery-plugin.test.ts
index 7dec67e93c..a0d2139217 100644
--- a/packages/runtime/src/migration-recovery-plugin.test.ts
+++ b/packages/runtime/src/migration-recovery-plugin.test.ts
@@ -45,7 +45,7 @@ function engineWith(rows: any[], opts: { failFind?: boolean; noJournalObject?: b
       if (opts.failFind) throw new Error('table is gone');
       if (obj !== JOURNAL) return [];
       const where = q?.where ?? {};
-      return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return rows.filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
     insert: async () => ({}),
   };
diff --git a/packages/runtime/src/security/resolve-execution-context.test.ts b/packages/runtime/src/security/resolve-execution-context.test.ts
index 8b1aac439c..521bd92919 100644
--- a/packages/runtime/src/security/resolve-execution-context.test.ts
+++ b/packages/runtime/src/security/resolve-execution-context.test.ts
@@ -17,6 +17,7 @@ function makeQl(apiKeyRows: any[]) {
       if (object !== 'sys_api_key') return [];
       return apiKeyRows.filter((row) => {
         for (const [k, v] of Object.entries(where)) {
+          if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`);
           if (row[k] !== v) return false;
         }
         return true;
diff --git a/packages/runtime/src/seed-loader.test.ts b/packages/runtime/src/seed-loader.test.ts
index 54159054a2..54d5a7b2ab 100644
--- a/packages/runtime/src/seed-loader.test.ts
+++ b/packages/runtime/src/seed-loader.test.ts
@@ -31,6 +31,7 @@ function createMockEngine(data: Record<string, any[]> = {}): IDataEngine {
       if (query?.filter) {
         return records.filter(r => {
           for (const [k, v] of Object.entries(query.filter)) {
+            if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`);
             if (r[k] !== v) return false;
           }
           return true;
diff --git a/packages/services/service-automation/src/builtin/wait-node-degraded-run.test.ts b/packages/services/service-automation/src/builtin/wait-node-degraded-run.test.ts
index af7d35b2bc..b06699f921 100644
--- a/packages/services/service-automation/src/builtin/wait-node-degraded-run.test.ts
+++ b/packages/services/service-automation/src/builtin/wait-node-degraded-run.test.ts
@@ -57,7 +57,7 @@ function makeFakeEngine() {
     async find(table: string, opts: any = {}) {
       const t = tables.get(table) ?? [];
       const out = opts.where
-        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => r[k] === v))
+        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }))
         : [...t];
       return opts.limit ? out.slice(0, opts.limit) : out;
     },
diff --git a/packages/services/service-automation/src/plugin-suspended-run-wiring.test.ts b/packages/services/service-automation/src/plugin-suspended-run-wiring.test.ts
index 78a8a88bf4..a42c3f7626 100644
--- a/packages/services/service-automation/src/plugin-suspended-run-wiring.test.ts
+++ b/packages/services/service-automation/src/plugin-suspended-run-wiring.test.ts
@@ -32,7 +32,7 @@ function fakeDataEngine(opts: { failReads?: string } = {}) {
             if (opts.failReads) throw new Error(opts.failReads);
             const where = options?.where ?? {};
             return [...rows.values()].filter(r =>
-                Object.entries(where).every(([k, v]) => r[k] === v));
+                Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
         },
         async insert(_object, data) { rows.set(String(data.id), { ...data }); return data; },
         async update(_object, data, options) {
diff --git a/packages/services/service-automation/src/runas-grant-resolution.integration.test.ts b/packages/services/service-automation/src/runas-grant-resolution.integration.test.ts
index e26a3490f2..fc55d8fda2 100644
--- a/packages/services/service-automation/src/runas-grant-resolution.integration.test.ts
+++ b/packages/services/service-automation/src/runas-grant-resolution.integration.test.ts
@@ -30,7 +30,7 @@ function fakeObjectQl(tables: Record<string, any[]>) {
   const match = (object: string, where: any): any[] =>
     (tables[object] ?? []).filter((r) =>
       Object.entries(where ?? {}).every(([k, v]) =>
-        v && typeof v === 'object' && '$in' in (v as any) ? (v as any).$in.includes(r[k]) : r[k] === v,
+        { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return v && typeof v === 'object' && '$in' in (v as any) ? (v as any).$in.includes(r[k]) : r[k] === v; },
       ),
     );
   const engine: any = {
diff --git a/packages/services/service-datasource/src/__tests__/datasource-admin-plugin.test.ts b/packages/services/service-datasource/src/__tests__/datasource-admin-plugin.test.ts
index 49c2f937cc..ba09d6ec74 100644
--- a/packages/services/service-datasource/src/__tests__/datasource-admin-plugin.test.ts
+++ b/packages/services/service-datasource/src/__tests__/datasource-admin-plugin.test.ts
@@ -248,11 +248,11 @@ describe('DatasourceAdminServicePlugin: runtime datasource durability', () => {
       getDriverByName() { return undefined; },
       findOne: async (_o: string, q: { where?: Record<string, unknown> }) => {
         const w = q.where ?? {};
-        return rows.find((r) => Object.entries(w).every(([k, v]) => r[k] === v));
+        return rows.find((r) => Object.entries(w).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
       },
       find: async (_o: string, q: { where?: Record<string, unknown> }) => {
         const w = q.where ?? {};
-        return rows.filter((r) => Object.entries(w).every(([k, v]) => r[k] === v));
+        return rows.filter((r) => Object.entries(w).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
       },
       insert: async (_o: string, row: Record<string, unknown>) => { rows.push({ ...row }); },
       update: async (_o: string, row: Record<string, unknown>, opts: { where: Record<string, unknown> }) => {
diff --git a/packages/services/service-job/src/db-job-adapter.degraded-outcome.test.ts b/packages/services/service-job/src/db-job-adapter.degraded-outcome.test.ts
index 7c00e75384..1908a7cf2b 100644
--- a/packages/services/service-job/src/db-job-adapter.degraded-outcome.test.ts
+++ b/packages/services/service-job/src/db-job-adapter.degraded-outcome.test.ts
@@ -29,7 +29,7 @@ function makeFakeEngine() {
     async find(table: string, opts: any = {}) {
       const t = tables.get(table) ?? [];
       let out = opts.where
-        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => r[k] === v))
+        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }))
         : [...t];
       if (opts.limit) out = out.slice(0, opts.limit);
       return out;
diff --git a/packages/services/service-job/src/db-job-adapter.test.ts b/packages/services/service-job/src/db-job-adapter.test.ts
index 1cd0b9f6c1..58a478b7de 100644
--- a/packages/services/service-job/src/db-job-adapter.test.ts
+++ b/packages/services/service-job/src/db-job-adapter.test.ts
@@ -12,7 +12,7 @@ function makeFakeEngine() {
     async find(table: string, opts: any = {}) {
       const t = tables.get(table) ?? [];
       let out = opts.where
-        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => r[k] === v))
+        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }))
         : [...t];
       if (opts.orderBy) {
         for (const ord of [...opts.orderBy].reverse()) {
diff --git a/packages/services/service-job/src/db-job-adapter.timeout.test.ts b/packages/services/service-job/src/db-job-adapter.timeout.test.ts
index 955452c217..ffe5cf9ecb 100644
--- a/packages/services/service-job/src/db-job-adapter.timeout.test.ts
+++ b/packages/services/service-job/src/db-job-adapter.timeout.test.ts
@@ -23,7 +23,7 @@ function makeFakeEngine() {
     async find(table: string, opts: any = {}) {
       const t = tables.get(table) ?? [];
       let out = opts.where
-        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => r[k] === v))
+        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }))
         : [...t];
       if (opts.limit) out = out.slice(0, opts.limit);
       return out;
diff --git a/packages/services/service-job/src/job-service-plugin.test.ts b/packages/services/service-job/src/job-service-plugin.test.ts
index f44a1ea395..7bf8f1e057 100644
--- a/packages/services/service-job/src/job-service-plugin.test.ts
+++ b/packages/services/service-job/src/job-service-plugin.test.ts
@@ -24,7 +24,7 @@ function makeFakeEngine() {
     async find(table: string, opts: any = {}) {
       const t = tables.get(table) ?? [];
       return opts.where
-        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => r[k] === v))
+        ? t.filter((r) => Object.entries(opts.where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }))
         : [...t];
     },
     async insert(table: string, data: any) {
diff --git a/packages/services/service-storage/src/attachment-access-hooks.test.ts b/packages/services/service-storage/src/attachment-access-hooks.test.ts
index c0f6b6176a..ce8d3509ce 100644
--- a/packages/services/service-storage/src/attachment-access-hooks.test.ts
+++ b/packages/services/service-storage/src/attachment-access-hooks.test.ts
@@ -18,13 +18,13 @@ function install(opts: {
     },
     find: async (_object, options: any) => {
       const rows = (opts.attachments ?? []).filter((r) =>
-        Object.entries(options?.where ?? {}).every(([k, v]) => r[k] === v),
+        Object.entries(options?.where ?? {}).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
       );
       return typeof options?.limit === 'number' ? rows.slice(0, options.limit) : rows;
     },
     findOne: async (_object, options: any) =>
       (opts.attachments ?? []).find((r) =>
-        Object.entries(options?.where ?? {}).every(([k, v]) => r[k] === v),
+        Object.entries(options?.where ?? {}).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
       ) ?? null,
     update: async () => ({}),
   };
diff --git a/packages/services/service-storage/src/file-reference-lifecycle.test.ts b/packages/services/service-storage/src/file-reference-lifecycle.test.ts
index b71ba779ce..e2526bf9ab 100644
--- a/packages/services/service-storage/src/file-reference-lifecycle.test.ts
+++ b/packages/services/service-storage/src/file-reference-lifecycle.test.ts
@@ -173,7 +173,7 @@ async function driveMultiUpdate(
   data: Record<string, unknown>,
 ) {
   const rows = (engine.tables[object] ?? []).filter((r) =>
-    Object.entries(where).every(([k, v]) => r[k] === v),
+    Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }),
   );
   const options = { multi: true, where };
   const scope: Record<string, unknown> = {};
@@ -234,7 +234,7 @@ async function driveDelete(engine: Engine, object: string, input: any) {
         return (engine.tables[object] ?? []).filter((r) => ids.some((i: unknown) => String(i) === String(r.id)));
       })()
     : where
-      ? (engine.tables[object] ?? []).filter((r) => Object.entries(where).every(([k, v]) => r[k] === v))
+      ? (engine.tables[object] ?? []).filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }))
       : [];
 
   const drop = () => {
diff --git a/packages/services/service-storage/src/lax-deviation-reclamation-gate.test.ts b/packages/services/service-storage/src/lax-deviation-reclamation-gate.test.ts
index 712ddc8873..a023a9457d 100644
--- a/packages/services/service-storage/src/lax-deviation-reclamation-gate.test.ts
+++ b/packages/services/service-storage/src/lax-deviation-reclamation-gate.test.ts
@@ -58,7 +58,7 @@ function ledgerEngine(rows: Array<Record<string, unknown>>) {
     getObject: (name: string) => (name in tables ? { name } : undefined),
     async find(object, options: any) {
       const where = options?.where ?? {};
-      return tables[object].filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return tables[object].filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
     async insert(object, data) {
       tables[object].push({ ...data });
@@ -85,11 +85,11 @@ function reapEngine() {
     registerHook() {},
     async find(object: string, options: any) {
       const where = options?.where ?? {};
-      return tables[object].filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+      return tables[object].filter((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; }));
     },
     async findOne(object: string, options: any) {
       const where = options?.where ?? {};
-      return tables[object].find((r) => Object.entries(where).every(([k, v]) => r[k] === v)) ?? null;
+      return tables[object].find((r) => Object.entries(where).every(([k, v]) => { if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`); return r[k] === v; })) ?? null;
     },
     async update(object: string, data: any, options?: any) {
       assertEngineUpdateDispatch(data, options);
diff --git a/scripts/check-where-matcher-conformance.mjs b/scripts/check-where-matcher-conformance.mjs
index 9e42934138..f537429e41 100644
--- a/scripts/check-where-matcher-conformance.mjs
+++ b/scripts/check-where-matcher-conformance.mjs
@@ -81,11 +81,69 @@
 //
 // ## How a candidate is discovered -- and why the control probe IS the filter
 //
-// Discovery is structural: a function in `packages/**/*.test.ts` with two or
-// more identifier parameters `(R, W, …)` whose body both indexes R by a
-// computed key (`R[k]` -- it reads fields off a row generically) and treats W
-// as a filter object (`Object.entries(W)` / `Object.keys(W)`, or a read of
-// `W.$or` / `W.$and`).
+// Discovery is structural: a function in `packages/**/*.test.ts` whose body
+// both indexes its FIRST parameter R by a computed key (`R[k]` -- it reads
+// fields off a row generically) and treats some other identifier W as a filter
+// object (`Object.entries(W)` / `Object.keys(W)`, or a read of `W.$or` /
+// `W.$and`).
+//
+// W is looked for in two places, in this order (#8615):
+//
+//   1. the function's OWN second parameter -- the `(row, where)` spelling, and
+//      the only one this gate could see before #8615.
+//   2. FAILING THAT, an ACCESS PATH the body reads as a filter, whose root is
+//      not one of this function's own parameters and RESOLVES in an enclosing
+//      scope -- either a same-file declaration (the `visibleDeclarations` walk
+//      already built for extraction) or a parameter bound by an enclosing
+//      function. This is the single-param `.filter()` callback that CLOSES OVER
+//      its `where`:
+//
+//        const where = query?.where ?? {};
+//        return rows.filter((r) => Object.entries(where).every(([k,v]) => r[k]===v));
+//
+//      Byte-for-byte the shape (b) body this gate already grades everywhere it
+//      appears as a second parameter -- the arity was never the defect, it was
+//      only what discovery happened to key on. "Not in the ledger" read as
+//      "conforming" for every one of them.
+//
+// A PATH rather than a bare identifier, because the capture is written both
+// ways and roughly half the corpus uses the indirect spelling: `where` (a local
+// `const`), but equally `opts.where`, `query?.where`, `q.where`,
+// `options.where`, `query.filter`. Keying on the identifier alone read the ROOT
+// of those (`opts`) as the filter, which is not a widening but a MIS-binding --
+// it made 21 real matchers UNJUDGED with a `TypeError` from the control probe,
+// i.e. it manufactured exactly the "could not run" failures this gate treats as
+// errors. Paths are reduced only through plain dotted access (optional chaining
+// and a `?? {}` / `|| {}` tail unwrapped); a call or a computed key yields no
+// path and no candidate, because the battery could not synthesise a binding.
+//
+// Requiring the root to RESOLVE is the load-bearing half of arm 2, and it is a
+// real scope walk rather than a name test on purpose: a root that binds nowhere
+// same-file is an import or a global, and grading those would have this gate
+// judge code it cannot see. What it is NOT is a tightening substitute for the
+// control probe -- arm 2 deliberately admits more structural candidates than it
+// admits matchers, and the probe below is what decides membership. Measured on
+// the corpus at #8615: arm 2 proposed 64 structural candidates, of which the
+// control probe seated 62 and dropped 2.
+//
+// The 2 it dropped are worth naming, because they are a REAL residual blind
+// spot rather than noise: both are inverted survivor filters inside a `delete`
+// double -- `(r) => !Object.entries(opts.where).every(…)`. They carry the same
+// shape (b) defect (a `$or` matches nothing, so the row is not deleted), but
+// they answer the control probe `false`/`true` instead of `true`/`false` and so
+// are correctly not row-SELECTING predicates by this gate's definition. Left
+// ungraded on purpose: teaching the probe to recognise a negated predicate
+// means guessing at intent, which is the naming-based reasoning this gate
+// exists to avoid. Tracked separately.
+//
+// For extraction, a captured W is RE-BOUND as a synthetic second parameter, so
+// the battery drives `(row, where)` uniformly whatever the source arity was --
+// the path is rebuilt outwards, so `opts.where` binds `opts` to
+// `{ where: <probe> }`. Re-binding rather than inlining W's declaration is
+// deliberate: the local-`const` spellings all initialise W from an enclosing
+// parameter (`query?.where ?? {}`, `opts?.where ?? {}`, `args.query?.$filter ??
+// {}`) that no standalone lift can supply, so inlining would have made every
+// one of them UNJUDGED -- a different way of not grading them.
 //
 // That heuristic alone over-matches. Rather than tighten it by guessing at
 // PARAMETER NAMES -- the failure `check-engine-double-contract` documents,
@@ -234,6 +292,93 @@ const identifiersIn = (src) => {
   return out;
 };
 
+/**
+ * Does `body` read `id` as a filter object? The two spellings are exactly the
+ * ones the two-parameter rule has always tested for — kept as one helper so the
+ * own-parameter arm and the captured arm cannot drift apart (the drift that let
+ * one spelling get fixed and the other not, in `check-engine-double-contract`).
+ */
+const readsAsFilter = (body, id) =>
+  new RegExp(`Object\\.(entries|keys)\\(\\s*${id}`).test(body) ||
+  new RegExp(`\\b${id}\\s*\\??\\.\\s*\\$(or|and)`).test(body);
+
+/** `where ?? {}`, `(where)`, `where!`, `where as any` -> `where`. */
+function unwrapExpr(e) {
+  for (;;) {
+    if (ts.isParenthesizedExpression(e) || ts.isNonNullExpression(e) || ts.isAsExpression(e)) {
+      e = e.expression;
+    } else if (
+      ts.isBinaryExpression(e) &&
+      (e.operatorToken.kind === ts.SyntaxKind.QuestionQuestionToken ||
+        e.operatorToken.kind === ts.SyntaxKind.BarBarToken)
+    ) {
+      e = e.left;
+    } else {
+      return e;
+    }
+  }
+}
+
+/**
+ * Reduce an expression to a plain ACCESS PATH: a root identifier plus dotted
+ * property names (`where` -> [where]; `opts?.where` -> [opts, where];
+ * `args.query.$filter` -> [args, query, $filter]). Anything else — a call, an
+ * element access, a computed key — returns null, because the battery cannot
+ * synthesise a binding for it.
+ */
+function accessPath(e) {
+  const parts = [];
+  for (let cur = unwrapExpr(e); ; cur = unwrapExpr(cur.expression)) {
+    if (ts.isIdentifier(cur)) return [cur.text, ...parts];
+    if (!ts.isPropertyAccessExpression(cur) || !ts.isIdentifier(cur.name)) return null;
+    parts.unshift(cur.name.text);
+  }
+}
+
+/**
+ * The two filter spellings, harvested as access paths instead of asserted
+ * against a known parameter name. Source order, deduplicated.
+ */
+function filterPathsIn(fnNode) {
+  const out = [];
+  const seen = new Set();
+  const add = (expr) => {
+    const path = accessPath(expr);
+    if (!path) return;
+    const k = path.join('.');
+    if (!seen.has(k)) { seen.add(k); out.push(path); }
+  };
+  const visit = (n) => {
+    if (
+      ts.isCallExpression(n) &&
+      ts.isPropertyAccessExpression(n.expression) &&
+      ts.isIdentifier(n.expression.expression) &&
+      n.expression.expression.text === 'Object' &&
+      (n.expression.name.text === 'entries' || n.expression.name.text === 'keys') &&
+      n.arguments.length >= 1
+    ) {
+      add(n.arguments[0]);
+    }
+    if (ts.isPropertyAccessExpression(n) && (n.name.text === '$or' || n.name.text === '$and')) {
+      add(n.expression);
+    }
+    ts.forEachChild(n, visit);
+  };
+  visit(fnNode.body);
+  return out;
+}
+
+/** Parameter names bound by the functions/methods enclosing `node`. */
+function enclosingParameters(node) {
+  const out = new Set();
+  for (let cur = node.parent; cur; cur = cur.parent) {
+    if (Array.isArray(cur.parameters)) {
+      for (const p of cur.parameters) if (ts.isIdentifier(p.name)) out.add(p.name.text);
+    }
+  }
+  return out;
+}
+
 /**
  * Structural candidates in one source text. Behavioural admission (the control
  * probe) happens later, in `judge` — this stage only proposes.
@@ -245,21 +390,39 @@ export function discoverInSource(text, label) {
   const visit = (node) => {
     if (isFn(node) && node.body) {
       const params = node.parameters.map((p) => (ts.isIdentifier(p.name) ? p.name.text : null));
-      if (params.length >= 2 && params[0] && params[1]) {
-        const body = node.body.getText(sf);
-        const [r, w] = params;
-        const indexesRow = new RegExp(`\\b${r}\\s*\\??\\.?\\[`).test(body);
-        const readsFilter =
-          new RegExp(`Object\\.(entries|keys)\\(\\s*${w}`).test(body) ||
-          new RegExp(`\\b${w}\\s*\\??\\.\\s*\\$(or|and)`).test(body);
-        if (indexesRow && readsFilter) {
+      const r = params[0];
+      const body = r ? node.body.getText(sf) : '';
+      if (r && new RegExp(`\\b${r}\\s*\\??\\.?\\[`).test(body)) {
+        // Arm 1 — the filter is this function's own second parameter.
+        let w = params.length >= 2 && params[1] && readsAsFilter(body, params[1]) ? params[1] : null;
+        let captured = false;
+        let declarations = null;
+        // Arm 2 (#8615) — no own filter parameter, so look for one CAPTURED
+        // from an enclosing scope. Resolution of the path's ROOT is required; a
+        // root binding nowhere in this file is an import or a global, and this
+        // gate does not grade code it cannot see.
+        if (!w) {
+          const own = new Set(params.filter(Boolean));
+          declarations = visibleDeclarations(node, sf);
+          const enclosing = enclosingParameters(node);
+          for (const path of filterPathsIn(node)) {
+            const root = path[0];
+            if (own.has(root)) continue;
+            if (!declarations.has(root) && !enclosing.has(root)) continue;
+            w = path;
+            captured = true;
+            break;
+          }
+        }
+        if (w) {
           const { line } = sf.getLineAndCharacterOfPosition(node.getStart(sf));
           out.push({
             file: label,
             line: line + 1,
             name: declaredName(node) ?? '(anonymous)',
             source: node.getText(sf),
-            declarations: visibleDeclarations(node, sf),
+            declarations: declarations ?? visibleDeclarations(node, sf),
+            capturedPath: captured ? w : null,
           });
         }
       }
@@ -275,12 +438,18 @@ export function discoverInSource(text, label) {
 // ---------------------------------------------------------------------------
 function buildCallable(candidate, dropped = new Set()) {
   const self = /^[A-Za-z_$][A-Za-z0-9_$]*$/.test(candidate.name) ? candidate.name : '__matcher';
+  const captured = candidate.capturedPath ?? null;
+  // A captured filter is supplied by the battery, so the path's ROOT must NOT
+  // be lifted in: its declaration would shadow the synthetic binding below, and
+  // every real instance initialises it from an enclosing parameter this lift
+  // cannot supply anyway (`query?.where ?? {}`).
+  const skip = captured ? new Set([...dropped, captured[0]]) : dropped;
   const included = new Map();
   let frontier = identifiersIn(candidate.source);
   for (let depth = 0; depth < 6; depth++) {
     const next = new Set();
     for (const id of frontier) {
-      if (included.has(id) || id === self || dropped.has(id)) continue;
+      if (included.has(id) || id === self || skip.has(id)) continue;
       const decl = candidate.declarations.get(id);
       if (!decl) continue;
       included.set(id, decl);
@@ -293,9 +462,21 @@ function buildCallable(candidate, dropped = new Set()) {
     /^(export\s+)?(default\s+)?(async\s+)?function\s+[A-Za-z_$][A-Za-z0-9_$]*/,
     'function',
   );
-  const code =
-    `${[...included.values()].join('\n')}\n` +
-    `const ${self} = ${normalised};\nreturn ${self};`;
+  // Re-bind a captured filter as a synthetic second parameter so the battery
+  // drives `(row, where)` uniformly, whatever arity the source was written at.
+  // The path is rebuilt outwards, so `opts.where` becomes `{ where: <probe> }`
+  // and `args.query.$filter` becomes `{ query: { $filter: <probe> } }`.
+  let definition = `const ${self} = ${normalised};`;
+  if (captured) {
+    let bound = '__os_where';
+    for (const prop of captured.slice(1).reverse()) bound = `{ ${JSON.stringify(prop)}: ${bound} }`;
+    definition =
+      `const ${self} = (__os_row, __os_where) => {\n` +
+      `  const ${captured[0]} = ${bound};\n` +
+      `  return (${normalised})(__os_row);\n` +
+      `};`;
+  }
+  const code = `${[...included.values()].join('\n')}\n${definition}\nreturn ${self};`;
   const js = ts.transpileModule(code, {
     compilerOptions: { target: ts.ScriptTarget.ES2022, isolatedModules: true },
   }).outputText;
@@ -524,6 +705,65 @@ const matches = (row: any, where: any): boolean => {
   return Object.entries(where).every(([k, v]) => k.startsWith('$') || eq(row[k], v));
 };`;
 
+// --- #8615: the captured-filter arm -------------------------------------
+// Every fixture below is a SINGLE-parameter callback. None of them has a second
+// parameter to key on, which is the whole point: before #8615 discovery could
+// not see one of these, so the gate could grade them neither green nor red.
+
+// Captured from a same-file `const`, combinator-blind. The shape the 17 sites
+// on the card were written in.
+const FIXTURE_CAPTURED_BLIND = `
+const run = (rows: any[], query: any) => {
+  const where = query?.where ?? {};
+  return rows.filter((r) => Object.entries(where).every(([k, v]) => r[k] === v));
+};`;
+
+// Captured through an ACCESS PATH rooted at an ENCLOSING PARAMETER. Roughly
+// half the corpus is spelled this way (`opts.where`, `q.where`, `query.filter`)
+// and keying on the root identifier alone mis-binds it into a TypeError.
+const FIXTURE_CAPTURED_PATH = `
+function makeDriver(rows: any[]) {
+  return {
+    find: (opts: any) => rows.filter((r) => Object.entries(opts.where).every(([k, v]) => r[k] === v)),
+  };
+}`;
+
+// Same shape, but the filter root binds NOWHERE in the file — an import or a
+// global. Discovery must decline it: this gate does not grade code it cannot
+// see. This is the fixture that holds the resolution requirement in place.
+const FIXTURE_CAPTURED_UNRESOLVED = `
+const run = (rows: any[]) =>
+  rows.filter((r) => Object.entries(IMPORTED_FILTER).every(([k, v]) => r[k] === v));`;
+
+// The filter expression is a CALL, so it reduces to no access path and the
+// battery could not synthesise a binding for it. Declined, not guessed at.
+const FIXTURE_CAPTURED_CALL = `
+const run = (rows: any[], get: any) =>
+  rows.filter((r) => Object.entries(get()).every(([k, v]) => r[k] === v));`;
+
+// A captured matcher that conjoins correctly — discovery must not assume that
+// "single-param callback" implies "defective".
+const FIXTURE_CAPTURED_CORRECT = `
+const run = (rows: any[], query: any) => {
+  const where = query?.where ?? {};
+  return rows.filter((r) =>
+    Object.entries(where).every(([k, v]) =>
+      k === '$or'
+        ? (v as any[]).some((b) => Object.entries(b).every(([bk, bv]) => r[bk] === bv))
+        : k === '$and'
+          ? (v as any[]).every((b) => Object.entries(b).every(([bk, bv]) => r[bk] === bv))
+          : r[k] === v));
+};`;
+
+// An INVERTED survivor filter inside a delete double. Structurally a candidate,
+// and it carries the same shape (b) defect — but it answers the control probe
+// backwards, so it is not a row-SELECTING predicate and the probe drops it.
+// Pinned as a fixture so this residual stays a KNOWN limit rather than drifting
+// into an accidental one.
+const FIXTURE_CAPTURED_NEGATED = `
+const run = (rows: any[], opts: any) =>
+  rows.filter((r) => !Object.entries(opts.where).every(([k, v]) => r[k] === v));`;
+
 function judgeFixture(src) {
   const found = discoverInSource(src, 'fixture.test.ts');
   return { found, results: found.map(judge) };
@@ -576,6 +816,40 @@ function selfTest() {
   const closure = judgeFixture(FIXTURE_HELPER_CLOSURE);
   expect('a matcher using a same-file helper is lifted', closure.results[0]?.verdict === 'CONFORMING');
 
+  // --- #8615: the captured-filter arm ------------------------------------
+  const capBlind = judgeFixture(FIXTURE_CAPTURED_BLIND);
+  expect('a single-param callback capturing a same-file `where` is discovered', capBlind.found.length === 1);
+  expect('its captured path is recorded', capBlind.found[0]?.capturedPath?.join('.') === 'where');
+  expect('a captured combinator-blind matcher is SILENT', capBlind.results[0]?.verdict === 'SILENT');
+
+  const capPath = judgeFixture(FIXTURE_CAPTURED_PATH);
+  expect('a filter captured through opts.where is discovered', capPath.found.length === 1);
+  expect('the whole access path is recorded', capPath.found[0]?.capturedPath?.join('.') === 'opts.where');
+  expect(
+    'a path-captured matcher is JUDGED, not left unrunnable',
+    capPath.results[0]?.verdict === 'SILENT',
+  );
+
+  const capUnresolved = judgeFixture(FIXTURE_CAPTURED_UNRESOLVED);
+  expect(
+    'a filter root that resolves nowhere same-file is NOT discovered',
+    capUnresolved.found.length === 0,
+  );
+
+  const capCall = judgeFixture(FIXTURE_CAPTURED_CALL);
+  expect('a filter expression that is a call yields no candidate', capCall.found.length === 0);
+
+  const capCorrect = judgeFixture(FIXTURE_CAPTURED_CORRECT);
+  expect('a conjoining captured matcher is discovered', capCorrect.found.length === 1);
+  expect('a conjoining captured matcher is CONFORMING', capCorrect.results[0]?.verdict === 'CONFORMING');
+
+  const capNegated = judgeFixture(FIXTURE_CAPTURED_NEGATED);
+  expect('an inverted survivor filter is a structural candidate', capNegated.found.length === 1);
+  expect(
+    'the control probe drops the inverted survivor filter (documented residual)',
+    capNegated.results[0]?.verdict === 'OUT_OF_SCOPE',
+  );
+
   // Reconciliation, both directions.
   const fakeMeasured = new Map([['a.test.ts', { silent: 1, unjudged: 0, details: [{ line: 1, name: 'm', result: { shapes: ['x'] } }] }]]);
   expect('an unbaselined silent matcher is an error', reconcile(fakeMeasured, {}).length === 1);
@@ -592,7 +866,10 @@ function selfTest() {
   }
   console.log(
     'OK  self-test: separates conjoining, early-returning, combinator-blind and refusing\n' +
-    '    matchers on synthetic fixtures; the control probe drops a non-predicate; the\n' +
+    '    matchers on synthetic fixtures; the control probe drops a non-predicate; single-\n' +
+    '    parameter callbacks capturing their filter — by name and by access path — are\n' +
+    '    discovered and judged, while an unresolvable root, a computed filter and an\n' +
+    '    inverted survivor filter are each declined for their own recorded reason; the\n' +
     '    ledger reconciles in both directions.',
   );
 }