@@ -0,0 +1,32 @@
+---
+"@objectstack/spec": minor
+"@objectstack/objectql": minor
+---
+
+fix(spec)!: a boolean, a `Date` or an array compared against a number field is refused with `INVALID_FILTER` / 400 at `where`, a per-aggregation `filter` and `having`, the same as a non-numeric string
+
+Clause-②: no (narrowing)
+
+<!-- adr-0087: not-required (no-migration-prescription) a refusal of a filter COMPARAND value at the engine's query door, decided by the published number-comparand verdict: no authorable key, spelling, export or stored shape moves (the verdict's function, its case table and its words keep their names; three exports are added), and no stored row is read or rewritten. What is refused is a boolean, a Date or an array compared against a declared numeric field or a numeric aggregated column; which number the caller meant is not something a ledger entry can decide (reading true as 1 is exactly the silent coercion this refuses). The other categories are closed on facts: both packages publish (not `unpublished`); no ADR-0087 id covers a filter comparand (not `registered` / `already-registered`); and the change is runtime behaviour, not a declaration (not `runtime-interface-only` / `type-surface-only`). -->
+
+**BREAKING**: this narrows what a filter may compare a number field with. `numberComparandDoorVerdict`, the published verdict the engine's number-comparand door consumes, judged strings only; it now also answers `door-refusal` for a boolean, a `Date` and an array, so the engine refuses them before any read, on every driver. It ships as `minor` under the launch-window convention for accept-set narrowings. The string rule is unchanged, and so are both packages' root exports except three additions to `@objectstack/spec/data`: `NON_NUMERIC_VALUE_FORMS` and the types `NonNumericValueForm` and `NonNumericComparandForm` (the refusal's `form` and the refusal site's `value` widen to carry a non-string).
+
+FROM `true` / `false`, a `Date`, or an array where one value belongs (a scalar operator's comparand, or a member of `$in` / `$nin` / `$between`), compared against a `number`, `currency`, `percent`, `rating`, `slider`, `progress` or `summary` field (or a `count` / `sum` / `avg`, or a numeric `min` / `max` / groupBy column in `having`) → TO `INVALID_FILTER` / 400, naming the field, its declared type, the comparand, its position and what is wrong with it. The fix is one line: send the number the filter means (`12`, `-3.5`, `1e3`), or compare a `Date` with a date or datetime field.
+
+Measured through `engine.find` / `engine.aggregate` and `POST /data/:object/query`, three rows (5, 12, 30) of a `number` field:
+
+| position | comparand | before: memory · SQLite · PostgreSQL 16 | now, on all three |
+|:--|:--|:--|:--|
+| `where` | `$gt true` | no rows · every row · `DATABASE_ERROR` (500) | `INVALID_FILTER` / 400 |
+| `where` | `$ne true` | every row · every row · 500 | `INVALID_FILTER` / 400 |
+| `where` | `$between [true, 20]` | no rows · two rows · 500 | `INVALID_FILTER` / 400 |
+| `where` | `$gt` a `Date` (in-process callers) | no rows · no rows · 500 | `INVALID_FILTER` / 400 |
+| `where` | `$gt [1]` | a driver's own 400, in each driver's words | `INVALID_FILTER` / 400, in one set of words |
+| `where` | a `$in` member `[1]` | no rows · a driver 400 · a driver 400 | `INVALID_FILTER` / 400 |
+| per-aggregation `filter` | `$gt true` / `$gt [1]` (`$gt` a `Date`) | count 3 (count 0), on all three | `INVALID_FILTER` / 400 |
+| `having` on `sum(amount)` | `$gt true` / `$gt [1]` (`$gt` a `Date`) | every group (no group), on all three | `INVALID_FILTER` / 400 |
+| all three positions | `$gt 10` (the numeric control) | 2 rows / count 2 / both groups | the same |
+
+**Who is affected.** A caller that compares a number field with a boolean or an array through any door that reaches the engine (a `where`, `$filter` or `filter` body of `POST /data/:object/query`, or an in-process engine call), or with a `Date` in-process (a flow, a hook, server code). No example app, platform object or other in-repo producer compares a number field that way.
+
+**Unchanged.** A number, a `bigint` (narrowed or refused by the comparand-type door, as before) and `null` (the null test) are answered as before. A value outside the accepted comparand types (`undefined`, a plain object, a `Map`) keeps the comparand-type door's own refusal and words. An array at an equality slot (implicit, `$eq`, `$ne`) keeps the comparand-shape door's refusal. A boolean or a `Date` compared against a boolean, date or datetime field is not this door's subject. Driver-direct callers that never pass through the engine keep each driver's native binding.
@@ -45,7 +45,9 @@ import { describe, it, expect, beforeEach } from 'vitest';
 import { ObjectStackProtocolImplementation } from '@objectstack/metadata-protocol';
 import {
   NON_NUMERIC_STRING_FORMS,
+  NON_NUMERIC_VALUE_FORMS,
   NUMBER_COMPARAND_DOOR_CASES,
+  normalizeFilterComparandTypes,
   NUMBER_COMPARAND_DOOR_FIXTURE,
   NUMBER_COMPARAND_DOOR_FIXTURE_OBJECT,
   NUMBER_COMPARAND_DOOR_LIST_OPERATORS,
@@ -157,8 +159,9 @@ describe('[#20351] the number-comparand declared-type door at the engine collect
     // The untyped formula is the table's only deferred row, and it is judged one door earlier.
     expect(DEFERRED).toHaveLength(0);
     expect(STAGED.map((c) => c.verdict)).toEqual(['passes']);
-    // Every refused form the grammar names is driven, not just the card's "abc".
-    expect(new Set(REFUSALS.map((c) => c.form))).toEqual(new Set(NON_NUMERIC_STRING_FORMS));
+    // Every refused form the grammar names is driven, not just the card's "abc" —
+    // and [#20502] every non-string form (a boolean, a Date, an array) beside them.
+    expect(new Set(REFUSALS.map((c) => c.form))).toEqual(new Set([...NON_NUMERIC_STRING_FORMS, ...NON_NUMERIC_VALUE_FORMS]));
     // Every judged position is driven both ways.
     const positions = (cs: readonly NumberComparandDoorCase[]) =>
       new Set(cs.filter((c) => c.key === 'f_number').map((c) => c.position.replace(/\[\d\]$/, '')));
@@ -383,6 +386,110 @@ describe('[#20351] the number-comparand declared-type door at the engine collect
     expect(await groups({ id: { $ne: 'abc' } })).toEqual(['r1', 'r2', 'r3']);
   });
 
+  // ── [#20502] a boolean, a Date, an array: one refusal at every position ──
+
+  /** The non-string comparands the widened verdict refuses — each a value the card measured three ways. */
+  const NON_STRING: ReadonlyArray<readonly [string, () => unknown, string]> = [
+    ['true', () => true, 'boolean'],
+    ['false', () => false, 'boolean'],
+    ['a Date', () => new Date(Date.UTC(2026, 0, 1)), 'date'],
+    ['an array', () => [10], 'array'],
+  ];
+
+  it('[#20502] refuses a boolean, a Date or an array in ONE aggregation\'s own filter, rooted at that position — no read', async () => {
+    for (const [name, value, form] of NON_STRING) {
+      for (const op of ['$gt', '$lte'] as const) {
+        reads.length = 0;
+        const err = await refusalOf(engine.aggregate(OBJECT, {
+          aggregations: [
+            { function: 'count', alias: 'all' },
+            { function: 'count', alias: 'bad', filter: { f_number: { [op]: value() } } },
+          ],
+        } as EngineAggregateOptions));
+        expect(err, `${name} ${op}`).not.toBeNull();
+        expect({ code: err!.code, status: err!.status }, `${name} ${op}`).toEqual({ code: 'INVALID_FILTER', status: 400 });
+        expect(err!.message, `${name} ${op}`).toContain(`aggregations[1].filter.f_number.${op}`);
+        expect(err!.message, `${name} ${op}`).toMatch(/^aggregate\('number_door_probe'\): filter on 'f_number' compares a declared number field/);
+        expect(findNonNumericComparand(engine.registry.getObject(OBJECT), { f_number: { [op]: value() } }), name)
+          .toMatchObject({ field: 'f_number', form });
+        expect(reads, `${name} ${op}`).toHaveLength(0);
+      }
+    }
+  });
+
+  it('[#20502] refuses a boolean, a Date or an array against a NUMERIC `having` column — count, sum and a numeric min alike', async () => {
+    for (const [name, value] of NON_STRING) {
+      for (const [fn, field] of [['count', undefined], ['sum', 'f_number'], ['min', 'f_currency']] as const) {
+        reads.length = 0;
+        const err = await refusalOf(engine.aggregate(OBJECT, {
+          groupBy: ['f_text'],
+          aggregations: [{ function: fn, ...(field ? { field } : {}), alias: 'total' }],
+          having: { total: { $gt: value() } },
+        } as EngineAggregateOptions));
+        expect(err, `${name} ${fn}`).not.toBeNull();
+        expect({ code: err!.code, status: err!.status }, `${name} ${fn}`).toEqual({ code: 'INVALID_FILTER', status: 400 });
+        expect(err!.message, `${name} ${fn}`).toContain('having.total.$gt');
+        expect(err!.message, `${name} ${fn}`).toContain("filter on 'total' compares a declared number field");
+        expect(reads, `${name} ${fn}`).toHaveLength(0);
+      }
+    }
+  });
+
+  it('[#20502] the numeric control at all three positions: a number reaches the driver and the evaluator as written', async () => {
+    reads.length = 0;
+    await engine.find(OBJECT, { where: { f_number: { $gt: 10 } } });
+    expect(reads[0]?.ast?.where).toEqual({ f_number: { $gt: 10 } });
+    const counted = await engine.aggregate(OBJECT, {
+      aggregations: [{ function: 'count', alias: 'all' }, { function: 'count', alias: 'm', filter: { f_number: { $gt: 10 } } }],
+    } as EngineAggregateOptions);
+    expect(Number((counted[0] as Record<string, unknown>).m)).toBe(2);
+    const groups = (await engine.aggregate(OBJECT, {
+      groupBy: ['id'],
+      aggregations: [{ function: 'sum', field: 'f_number', alias: 'total' }],
+      having: { total: { $gt: 10 } },
+    } as EngineAggregateOptions)).map((r) => (r as Record<string, unknown>).id).sort();
+    expect(groups).toEqual(['r2', 'r3']);
+  });
+
+  it('[#20502] the same mistake as FilterArray sugar and inside $and / $or / $not — one answer per mistake', async () => {
+    const sugar = await refusalOf(
+      engine.find(OBJECT, { where: [['f_number', '>', true]] } as unknown as EngineQueryOptions),
+    );
+    expect({ code: sugar!.code, status: sugar!.status }).toEqual({ code: 'INVALID_FILTER', status: 400 });
+    expect(sugar!.message).toContain("filter on 'f_number' compares a declared number field against true at where.f_number.$gt");
+    for (const where of [
+      { $and: [{ f_text: 'a' }, { f_number: { $gt: true } }] },
+      { $or: [{ f_text: 'a' }, { f_currency: { $in: [1, new Date(0)] } }] },
+      { $not: { f_percent: { $between: [[1], 10] } } },
+    ]) {
+      const err = await refusalOf(engine.find(OBJECT, { where: where as FilterCondition }));
+      expect({ code: err?.code, status: err?.status }, JSON.stringify(where)).toEqual({ code: 'INVALID_FILTER', status: 400 });
+    }
+    expect(reads).toHaveLength(0);
+    expect(engine.judgeFilter(OBJECT, { f_number: { $gt: new Date(0) } })).toMatchObject({ ok: false, code: 'INVALID_FILTER', status: 400 });
+  });
+
+  it('[#20502] a value OUTSIDE the accepted comparand types is the comparand-TYPE door\'s refusal, in that door\'s words, on both spellings', async () => {
+    const context = `find('${OBJECT}')`;
+    for (const [name, value] of [['a plain object', { a: 1 }], ['undefined', undefined], ['a Map', new Map()]] as const) {
+      const where = { f_number: { $gt: value } };
+      // The verdict passes it, so THIS door has no second opinion …
+      expect(findNonNumericComparand(engine.registry.getObject(OBJECT), where), name).toBeNull();
+      // … and the engine answers exactly what the comparand-type door answers.
+      let expected: Error | undefined;
+      try { normalizeFilterComparandTypes(where, context); } catch (e) { expected = e as Error; }
+      expect(expected, name).toBeDefined();
+      const err = await refusalOf(engine.find(OBJECT, { where: where as FilterCondition }));
+      expect({ code: err?.code, status: err?.status }, name).toEqual({ code: 'INVALID_FILTER', status: 400 });
+      expect(err!.message, name).toBe(expected!.message);
+    }
+    const sugar = await refusalOf(engine.find(OBJECT, { where: [['f_number', '>', { a: 1 }]] } as unknown as EngineQueryOptions));
+    let expected: Error | undefined;
+    try { normalizeFilterComparandTypes({ f_number: { $gt: { a: 1 } } }, context); } catch (e) { expected = e as Error; }
+    expect(sugar!.message).toBe(expected!.message);
+    expect(reads).toHaveLength(0);
+  });
+
   it('GUARD the having walk narrows copy-on-write and judges only columns classed numeric', () => {
     const classes = new Map([['total', 'numeric' as const], ['label', 'text' as const], ['unknown', undefined]]);
     const having = { total: { $in: ['1', 2] }, label: { $eq: 'abc' }, unknown: { $eq: 'abc' } };
 
@@ -5,8 +5,11 @@
  * filter collection point: the fifth gate on the seam that already carries
  * the #5869 comparand-shape gate, the #8296 unmaterializable-field gate, the
  * #15661 text-operator declared-type gate and the #8690 temporal-comparand
- * gate. It answers a fifth question about the same predicate: *is this string
- * a number the column can be compared with.*
+ * gate. It answers a fifth question about the same predicate: *is this
+ * comparand a number the column can be compared with.* [#20502] widened the
+ * question from strings to every comparand, in the spec's verdict alone: a
+ * boolean, a `Date` and an array are refused beside a non-numeric string,
+ * and this file changed only to carry a refused value that is not a string.
  *
  * ## The direction this implements (triage, recorded on #20336)
  *
@@ -45,9 +48,12 @@
  *
  * ## The door's two answers
  *
- * - **Refuse** a string the grammar does not read as a number: `INVALID_FILTER`
- *   / 400, the existing filter envelope, in the contract's words, before any
- *   driver is resolved. A `{placeholder}` is refused too, unresolved: every
+ * - **Refuse** a string the grammar does not read as a number, and a boolean,
+ *   a `Date` or an array (#20502): `INVALID_FILTER` / 400, the existing filter
+ *   envelope, in the contract's words, before any driver is resolved. A value
+ *   outside the comparand-type door's accepted set (`undefined`, a plain
+ *   object, a `Map`) passes the verdict and is refused by that door, one call
+ *   later, in its own words. A `{placeholder}` is refused too, unresolved: every
  *   filter token resolves to an id or a date, never a number (the contract
  *   argues it), and this door runs before `resolveWhereTokens`, as its
  *   temporal neighbour records it must.
@@ -178,7 +184,11 @@ function fieldMetaOf(def: unknown): NumberComparandDoorFieldMeta | null {
   return typeof returnType === 'string' ? { type, returnType } : { type };
 }
 
-/** One comparand at a judged position: the spec's verdict, routed. */
+/**
+ * One comparand at a judged position: the spec's verdict, routed. Whatever
+ * the comparand is — a string, a boolean, a `Date`, an array (#20502) — the
+ * verdict alone decides; this function only turns its answer into an outcome.
+ */
 function judgeComparand(
   meta: NumberComparandDoorFieldMeta,
   field: string,
@@ -195,8 +205,7 @@ function judgeComparand(
       declaredType: meta.type,
       ...(meta.returnType === undefined ? {} : { returnType: meta.returnType }),
       path,
-      // `door-refusal` is answered for a string comparand only.
-      value: comparand as string,
+      value: comparand,
       form: verdict.form,
     },
   };
@@ -292,7 +301,7 @@ function declaredMetaOf(schema: unknown): MetaOf | null {
 }
 
 /**
- * Walk one `FilterCondition` and return the FIRST string a declared numeric
+ * Walk one `FilterCondition` and return the FIRST comparand a declared numeric
  * field cannot be compared with, or `null`.
  *
  * Exported for the same reason the sibling walks are: a consumer that needs to
@@ -314,7 +323,7 @@ function refuse(context: string, refusal: NonNumericComparand): never {
 }
 
 /**
- * Refuse every string a declared numeric field cannot be compared with, and
+ * Refuse every comparand a declared numeric field cannot be compared with, and
  * narrow every numeric string to its number — `INVALID_FILTER` / 400, this
  * package's existing filter envelope, in the contract's words. No code is
  * minted.