diff --git a/.changeset/objectql-checkboxes-option-gating.md b/.changeset/objectql-checkboxes-option-gating.md
new file mode 100644
index 0000000000..e1de36fa02
--- /dev/null
+++ b/.changeset/objectql-checkboxes-option-gating.md
@@ -0,0 +1,10 @@
+---
+"@objectstack/objectql": patch
+---
+
+**Enforce per-option `visibleWhen` on `checkboxes` fields, and match option values by string form (objectui#2729).** Server-side per-option gating already covered `select` / `multiselect` / `radio`, but two holes let gated values through on write:
+
+- **`checkboxes` was not enforced.** `CHOICE_FIELD_TYPES` omitted `checkboxes`, so a gated `checkboxes` option (whose client widget cascades identically to `multiselect` since objectui#2715) was hidden in the UI but accepted from a crafted write. Added `checkboxes` to the enforced set — its picked values are now re-evaluated against each option's `visibleWhen` (record + `current_user`) on insert/update/bulk-update, element-wise, like `multiselect`.
+- **Numeric option values could slip the gate.** Option matching used strict `===`, but the enum-membership validator compares by `String(...)`. A numeric option value submitted as a string (a normal REST/JSON round-trip) passed the enum check yet missed its `visibleWhen` gate (fail-open). Matching now coerces both sides with `String(...)`, so the two validators agree on which option a written value denotes.
+
+Behavior for `select` / `multiselect` / `radio` is unchanged. Fail-open on unbound `current_user` / unevaluable predicates is preserved.
diff --git a/packages/objectql/src/validation/rule-validator.option-visibility.test.ts b/packages/objectql/src/validation/rule-validator.option-visibility.test.ts
index 6c6ec07a45..5935a36554 100644
--- a/packages/objectql/src/validation/rule-validator.option-visibility.test.ts
+++ b/packages/objectql/src/validation/rule-validator.option-visibility.test.ts
@@ -128,6 +128,62 @@ describe('per-option visibleWhen — multi-select element-wise', () => {
   });
 });
 
+describe('per-option visibleWhen — checkboxes element-wise (objectui#2715)', () => {
+  // `checkboxes` is the multi-value sibling of `multiselect`; its gated options
+  // must be enforced server-side too (client cascading shipped in objectui#2735).
+  const checks = {
+    fields: {
+      country: { type: 'select', options: [{ value: 'cn' }, { value: 'us' }] },
+      provinces: {
+        type: 'checkboxes',
+        options: [
+          { value: 'zj', visibleWhen: "record.country == 'cn'" },
+          { value: 'gd', visibleWhen: "record.country == 'cn'" },
+          { value: 'ca', visibleWhen: "record.country == 'us'" },
+        ],
+      },
+    },
+  };
+  it('rejects when any checked element is invalid for the parent', () => {
+    expect(() => evaluateValidationRules(checks, { country: 'cn', provinces: ['zj', 'ca'] }, 'insert')).toThrow(
+      ValidationError,
+    );
+  });
+  it('accepts when every checked element is valid', () => {
+    expect(() =>
+      evaluateValidationRules(checks, { country: 'cn', provinces: ['zj', 'gd'] }, 'insert'),
+    ).not.toThrow();
+  });
+  it('accounts for a gated checkboxes option in needsPriorRecord', () => {
+    expect(needsPriorRecord(checks)).toBe(true);
+  });
+});
+
+describe('per-option visibleWhen — value/option type coercion', () => {
+  // A numeric option value submitted as a string (a common REST/JSON round-trip)
+  // must still hit its gate — matching the enum validator's String(...) compare.
+  const numeric = {
+    fields: {
+      country: { type: 'select', options: [{ value: 'cn' }, { value: 'us' }] },
+      zone: {
+        type: 'select',
+        options: [
+          { value: 1, visibleWhen: "record.country == 'cn'" },
+          { value: 2, visibleWhen: "record.country == 'us'" },
+        ],
+      },
+    },
+  };
+  it('gates a numeric option value sent as a string', () => {
+    expect(() => evaluateValidationRules(numeric, { country: 'us', zone: '1' }, 'insert')).toThrow(
+      ValidationError,
+    );
+  });
+  it('accepts the string form when the gate passes', () => {
+    expect(() => evaluateValidationRules(numeric, { country: 'cn', zone: '1' }, 'insert')).not.toThrow();
+  });
+});
+
 describe('needsPriorRecord accounts for option visibleWhen', () => {
   it('is true when a choice field has a gated option (cascade may reference a prior sibling)', () => {
     expect(needsPriorRecord(schema)).toBe(true);
diff --git a/packages/objectql/src/validation/rule-validator.ts b/packages/objectql/src/validation/rule-validator.ts
index 1e6c7ce967..608d951fd2 100644
--- a/packages/objectql/src/validation/rule-validator.ts
+++ b/packages/objectql/src/validation/rule-validator.ts
@@ -374,12 +374,16 @@ interface ConditionalFieldDef {
   readonly?: boolean;
   /** Field type — scopes per-option `visibleWhen` enforcement to choice fields. */
   type?: string;
-  /** Select/multiselect/radio options; an option may gate itself with `visibleWhen`. */
+  /** select/multiselect/radio/checkboxes options; an option may gate itself with `visibleWhen`. */
   options?: Array<ConditionalFieldOption | null | undefined>;
 }
 
-/** Choice fields whose picked value(s) are drawn from `options`. */
-const CHOICE_FIELD_TYPES = new Set(['select', 'multiselect', 'radio']);
+/**
+ * Choice fields whose picked value(s) are drawn from `options`. Includes the
+ * multi-value `checkboxes` (its client widget cascades identically to
+ * `multiselect`, objectui#2715) so its gated options are enforced server-side too.
+ */
+const CHOICE_FIELD_TYPES = new Set(['select', 'multiselect', 'radio', 'checkboxes']);
 
 /** True when a choice field carries at least one option gated by `visibleWhen`. */
 function fieldHasOptionVisibility(def: ConditionalFieldDef | undefined | null): boolean {
@@ -410,8 +414,8 @@ function toExpression(cond: string | Expression): Expression {
 /**
  * Per-option authorization / cascade enforcement (objectui#2284).
  *
- * A `select` / `multiselect` / `radio` option may gate itself with a
- * `visibleWhen` CEL predicate, evaluated against the live record + `current_user`
+ * A `select` / `multiselect` / `radio` / `checkboxes` option may gate itself with
+ * a `visibleWhen` CEL predicate, evaluated against the live record + `current_user`
  * (the same predicate the client uses to hide the option). Client-side hiding is
  * UX, not a security boundary — a caller can still submit a hidden value — so on
  * write we re-evaluate the predicate for the *picked* value(s) and reject any
@@ -443,7 +447,10 @@ function evaluateOptionVisibility(
     if (raw === undefined || raw === null || raw === '') continue;
     const picked = Array.isArray(raw) ? raw : [raw];
     for (const value of picked) {
-      const opt = def.options!.find((o) => o != null && o.value === value);
+      // Match by string form, mirroring the enum validator (record-validator
+      // compares `String(...)`). A numeric option value sent/stored as a string
+      // (or vice-versa) must still hit its gate, not silently fail-open.
+      const opt = def.options!.find((o) => o != null && String(o.value) === String(value));
       // Unknown value (not in options) or an ungated option → nothing to enforce
       // here; an out-of-set value is the enum validator's concern, not ours.
       if (!opt || opt.visibleWhen == null) continue;