@@ -0,0 +1,26 @@
+---
+'@objectstack/metadata-protocol': minor
+---
+
+The runtime save door refuses every hook that carries no `body`, including one with neither a `body` nor a `handler`: a hook stored there ships with no code package, so its `body` is the only code it can run
+
+Clause-②: no (narrowing)
+
+<!-- adr-0087: not-required (no-migration-prescription) A validity narrowing at one runtime write door over existing keys: no key of `HookSchema` or of any other metadata schema is removed, renamed or re-shaped, so there is no tombstone and nothing mechanical for `objectstack migrate meta` to rewrite. What `body` a refused hook should carry is authoring intent no conversion entry can decide. New saves are refused with the remedy; a row stored before this change keeps its bytes, and no stored row is re-saved (measured: `migrateStoredMetadata({ apply: true })` on a stored hook row with neither field reports it canonical, failed 0, and the bytes are unchanged). The census of writers through this door, taken first at `1db5322ba2`: Studio at the objectui pin (`ab18797215`, unchanged since the census of the handler-only refusal, which read its hook skeleton carrying a `body`); objectstack `examples/**` and `packages/qa/**` seed no `sys_metadata` hook rows (zero `type: 'hook'` items); `os meta register` forwards the author's own file and emits no hook of its own; the artifact, boot and install-local doors never call `saveMetaItem` for a hook (every call site in the tree saves a fixed type other than `hook`, or forwards an author's request: the REST and dispatcher `/meta` saves, `migrateStoredMetadata`, `duplicatePackage`). The only first-party bodies of this shape were test probes (seven suites), which now carry a `body`. Package duplication of a package holding such a row now reports that row as failed with this refusal (measured: copied 1, failed 1, the source rows' bytes unchanged). Hosted tenants and the cloud AI author were not measured. The other categories are closed on facts: the package publishes (not unpublished); no ADR-0087 id covers this rule and this diff adds none (not registered / already-registered); and the change narrows what a runtime write door accepts, not a runtime interface or a type surface alone (not runtime-interface-only / type-surface-only). -->
+
+**BREAKING** accept-set narrowing at the runtime save door, shipped as `minor` under the repo's launch-window convention for breaking changes, the grade the same door's earlier refusals shipped with.
+
+**One rule.** `saveMetaItem`, which `PUT /api/v1/meta/hook/:name` and the dispatcher's metadata save both call, now refuses every `hook` that carries no `body`. It already refused a hook whose `handler` names a function and that carries no `body`; that refusal is now one case of this rule, with the same envelope and the same message. The new case is a hook with neither field (or with an empty `handler`). Before this change the door answered 200 for it, the hook was served by name, the runtime skipped it at every re-sync (`skipping hook with unresolved handler`, in the server log only), and it never ran. The refusal is `VALIDATION_ERROR` / 400, in draft and in publish mode, before anything is stored or bound. It names the hook and prescribes a `body`.
+
+**Before and after** (with `{ name: 'stamp_status', object: 'crm_note', events: ['beforeInsert'] }`):
+
+- Before: 200 `Saved hook 'stamp_status'`, the row stored and served by name, and the hook never run.
+- After: 400 `VALIDATION_ERROR`, naming `stamp_status`, and nothing stored.
+
+**What still saves.** A hook with a `body`, with or without a `handler` beside it: the binder runs the body and never consults the name. A malformed `body` still gets the type schema's located `422 INVALID_METADATA`.
+
+**What is unchanged.** `HookSchema` still accepts a hook with no `body`, because a build artifact carries a `handler` hook: `objectstack build` lowers an inline function to the hook's name and ships the function in the artifact's runtime module. A hook in an artifact or a `defineStack` config binds on its own door, which never reaches this one. `os validate` and `os build` are unchanged.
+
+**Rows stored before this change.** They keep their bytes, nothing re-saves them, and the runtime skips them at every re-sync as before. A new save of one, a re-save included, is refused until it carries a `body`. Package duplication reports such a row as failed with this refusal; `migrate meta --stored` leaves it as it is. Delete stays open.
+
+**The fix.** Give the hook a `body`: sandboxed JS (`{ language: 'js', source }`) or an expression (`{ language: 'expression', source }`). A hook that must run a package's own function belongs in that package's code, where its `handler` resolves.
@@ -402,7 +402,10 @@ describe('code-only metadata types are refused on every kernel (#5086)', () => {
                 const result = await protocol.saveMetaItem({
                     type: 'hook',
                     name: 'rc3_probe_hook',
-                    item: { name: 'rc3_probe_hook', object: 'task', events: ['beforeUpdate'] },
+                    // [#21689] A body-carrying hook: the save door refuses a hook
+                    // with no `body` (it could never run), and this case measures
+                    // the code-only gate, not that refusal.
+                    item: { name: 'rc3_probe_hook', object: 'task', events: ['beforeUpdate'], body: { language: 'js', source: 'return;' } },
                 });
                 expect(result.success).toBe(true);
                 expect(metaRows(rows).length).toBe(1);
@@ -511,7 +514,9 @@ describe('code-only metadata types are refused on every kernel (#5086)', () => {
             },
             {
                 type: 'hook', // allowRuntimeCreate only
-                item: { name: 'rc3_receipt_view', object: 'task', events: ['beforeUpdate'] },
+                // [#21689] With a `body`: the door refuses a hook without one,
+                // and this matrix measures the receipt, not that refusal.
+                item: { name: 'rc3_receipt_view', object: 'task', events: ['beforeUpdate'], body: { language: 'js', source: 'return;' } },
             },
             {
                 type: 'webhook', // no static registry entry (plugin-registered)
 
@@ -570,3 +570,50 @@ describe('[#21658] a hook naming a function in `handler` with no `body` is refus
         expect(rows.size).toBe(0);
     });
 });
+
+// ═══════════════════════════════════════════════════════════════════════════
+// 8. #21689 — one predicate: the `hook` door refuses every hook with no `body`
+// ═══════════════════════════════════════════════════════════════════════════
+//
+// Section 7's refusal, generalised. A hook this door stores ships with no code
+// package, so a `body` is the only code it can run: a hook with neither a
+// `body` nor a `handler` is never bound either (the binder skips it at every
+// re-sync). The door judges by one predicate — no `body` object — and section
+// 7's `handler` form is one case of it, with the same envelope. An empty
+// `handler` names no function, so it reads as no `handler`.
+
+describe('[#21689] a hook with no `body` and no function in `handler` is refused at the metadata door', () => {
+    const bare = (extra: Record<string, unknown> = {}) => ({
+        name: 'stamp_status',
+        object: 'hks_note',
+        events: ['beforeInsert'],
+        ...extra,
+    });
+
+    it.each([
+        ['publish', 'neither field', undefined, {}],
+        ['draft', 'neither field', 'draft', {}],
+        ['publish', 'an empty `handler`', undefined, { handler: '' }],
+    ] as const)('%s mode, %s — VALIDATION_ERROR / 400, naming the hook, prescribing a `body`, nothing stored', async (_label, _shape, mode, extra) => {
+        const { protocol, rows } = makeProtocol();
+        let err: any;
+        try {
+            await protocol.saveMetaItem({
+                type: 'hook',
+                name: 'stamp_status',
+                item: bare(extra),
+                writeFace: 'meta-envelope',
+                actor: 'usr_admin',
+                ...(mode ? { mode } : {}),
+            });
+        } catch (e) {
+            err = e;
+        }
+
+        expect(err).toBeInstanceOf(Error);
+        expect({ code: err.code, status: err.status }).toEqual({ code: 'VALIDATION_ERROR', status: 400 });
+        expect(err.message).toContain("'stamp_status'");
+        expect(err.message).toContain('Give it a `body`');
+        expect(rows.size).toBe(0);
+    });
+});
@@ -143,7 +143,10 @@ const SAMPLE: Array<{
         type: 'hook',
         klass: 'declared',
         creatable: true,
-        item: { name: 'probe_hook', object: 'task', events: ['beforeInsert'] },
+        // [#21689] With a `body`: the mint door refuses a hook without one (it
+        // could never run), which would misread the advertisement this suite
+        // measures, as a 422 from schema resolution would.
+        item: { name: 'probe_hook', object: 'task', events: ['beforeInsert'], body: { language: 'js', source: 'return;' } },
     },
     {
         // The `false` direction of class 1, and it must be present: a listing
 
@@ -129,7 +129,9 @@ const OVERLAYLESS_PROBES: Record<string, Record<string, unknown>> = {
         sharingModel: 'private',
         fields: { name: { type: 'text', label: 'Name' } },
     },
-    hook: { name: 'rc5_acct', object: 'task', events: ['beforeUpdate'] },
+    // [#21689] With a `body`: the door refuses a hook without one before the
+    // receipt is built, as it refuses a body the schema rejects.
+    hook: { name: 'rc5_acct', object: 'task', events: ['beforeUpdate'], body: { language: 'js', source: 'return;' } },
     seed: { object: 'task', records: [] },
     action: { name: 'rc5_acct', label: 'Convert', type: 'script', objectName: 'task', target: 'convertHandler' },
     flow: {
 
@@ -781,47 +781,58 @@ function resolveOverlaySchema(type: string, _item: unknown): z.ZodTypeAny | null
 }
 
 /**
- * [#21658] The save door's refusal of a `hook` whose `handler` names a
- * function and that carries no `body`: such a hook can never run once this
- * door has stored it.
- *
- * Why it can never bind. A hook's `handler` name resolves inside the hook's
- * own package only (the maintainer's ruling on #21604, letter B; the binder's
- * `resolveHandler` in `@objectstack/objectql`'s `hook-binder.ts`). A hook this
- * door stores ships with no code package: the runtime binds every stored hook
- * under the synthetic owner `metadata-service` (`ObjectQLPlugin`'s authored
- * hook re-sync), with no `functions` map, and no package of that name
- * registers functions. So the name has nothing to resolve against, and the
- * binder refuses the hook at registration (`INVALID_REFERENCE` / 400, logged
- * at `error`) after this door has already answered success. Refusing it here
- * says so to the author, before anything is stored.
- *
- * The predicate is the binder's own body-first test: a `body` object is bound
- * through the body runner and the `handler` is never consulted, so a hook
- * carrying BOTH a `body` and a `handler` saves (its body runs), as it installs
- * on the install-local door. Asked after the type schema has accepted the
- * body, so `body` here is either absent or a declared hook body, and a
- * malformed `body` gets the schema's own located `422` instead of this
- * refusal's "give it a body".
+ * [#21658, #21689] The save door's refusal of a `hook` that carries no `body`:
+ * such a hook can never run once this door has stored it. One predicate, two
+ * shapes it meets, one envelope: a hook whose `handler` names a function, and a
+ * hook with neither field.
+ *
+ * Why it can never run. A hook this door stores ships with no code package:
+ * the runtime binds every stored hook under the synthetic owner
+ * `metadata-service` (`ObjectQLPlugin`'s authored hook re-sync), with no
+ * `functions` map, and no package of that name registers functions. So a
+ * `body`, which is stored with the hook, is the only code it can run.
+ *
+ *   - A `handler` name resolves inside the hook's own package only (the
+ *     maintainer's ruling on #21604, letter B; the binder's `resolveHandler` in
+ *     `@objectstack/objectql`'s `hook-binder.ts`), so it has nothing to resolve
+ *     against, and the binder refuses the hook at registration
+ *     (`INVALID_REFERENCE` / 400, logged at `error`).
+ *   - A hook with neither field has nothing to bind at all, and the binder
+ *     skips it at every re-sync (`skipping hook with unresolved handler`,
+ *     logged at `warn`).
+ *
+ * Either way the door would already have answered success, and the hook would
+ * be served by name and never run. Refusing it here says so to the author,
+ * before anything is stored.
+ *
+ * The predicate is the binder's own body-first test, the judgement
+ * install-local's `collectHooksWithoutBody` makes on its own door (#21585): a
+ * `body` object is bound through the body runner and the `handler` is never
+ * consulted, so a hook carrying BOTH a `body` and a `handler` saves (its body
+ * runs), and every hook without a `body` object is refused, whatever its
+ * `handler` holds. Asked after the type schema has accepted the body, so
+ * `body` here is either absent or a declared hook body, and a malformed `body`
+ * gets the schema's own located `422` instead of this refusal's "give it a
+ * body".
  *
  * ⛔ Not a `HookSchema` rule: a build artifact legitimately carries the string
  * form (`objectstack build` lowers an inline function to the hook's name and
  * ships the function in the artifact's runtime module), and the artifact and
  * boot doors never reach `saveMetaItem`. This is the runtime-authoring door's
- * rule only, the same shape install-local refuses on its own door (#21585).
+ * rule only.
  *
  * Every writer through this door is judged: the REST and dispatcher saves, in
  * draft and in publish mode, and the two server-stated re-savers
  * (`migrateStoredMetadata`, `duplicatePackage`), which record this refusal as
  * the row's failure. A row stored before this rule keeps its bytes.
  *
  * `VALIDATION_ERROR` / 400, the envelope of the name check the door runs on
- * every body (`savedItemNameRefusal`). The message names the hook and its
- * `handler`, prescribes the `body` first, and only then explains: a 4xx
- * message crosses the REST boundary bounded at 500 characters with its TAIL
- * truncated, and the whole sentence stays under that bound for any hook and
- * function name shorter than about 65 characters each. Runtime words carry no
- * tracker number.
+ * every body (`savedItemNameRefusal`). The message names the hook (and the
+ * function, when its `handler` names one), prescribes the `body` first, and
+ * only then explains: a 4xx message crosses the REST boundary bounded at 500
+ * characters with its TAIL truncated, and the whole sentence stays under that
+ * bound for any hook and function name shorter than about 65 characters each.
+ * Runtime words carry no tracker number.
  */
 function runtimeHookWithoutBodyRefusal(
     singularType: string,
@@ -832,12 +843,15 @@ function runtimeHookWithoutBodyRefusal(
     if (!item || typeof item !== 'object' || Array.isArray(item)) return undefined;
     const hook = item as { handler?: unknown; body?: unknown };
     if (hook.body && typeof hook.body === 'object') return undefined;
-    if (typeof hook.handler !== 'string' || hook.handler === '') return undefined;
+    const prescription = 'Give it a `body` (sandboxed JS, `{ language: \'js\', source }`, or an expression), '
+        + 'which is stored with the hook. A hook saved through the metadata API ships with no code package, so ';
     const err = new Error(
-        `Invalid hook: '${saveName}' names the function '${hook.handler}' in its \`handler\` and carries no \`body\`, `
-        + 'so it can never run. Give it a `body` (sandboxed JS, `{ language: \'js\', source }`, or an expression), '
-        + 'which is stored with the hook. A hook saved through the metadata API ships with no code package, so it '
-        + "holds no functions, and a `handler` name resolves only inside the hook's own package.",
+        typeof hook.handler === 'string' && hook.handler !== ''
+            ? `Invalid hook: '${saveName}' names the function '${hook.handler}' in its \`handler\` and carries no \`body\`, `
+                + `so it can never run. ${prescription}it holds no functions, and a \`handler\` name resolves only inside `
+                + "the hook's own package."
+            : `Invalid hook: '${saveName}' carries no \`body\`, so it has nothing to run. ${prescription}`
+                + 'its `body` is the only code it can run.',
     ) as Error & { code: 'VALIDATION_ERROR'; status: 400 };
     err.code = 'VALIDATION_ERROR';
     err.status = 400;
@@ -18947,12 +18961,13 @@ export class ObjectStackProtocolImplementation implements
             }
         }
 
-        // [#21658] A hook whose `handler` names a function and that carries
-        // no `body` can never run once stored here: a stored hook ships with
-        // no code package, and a `handler` name resolves only inside the
-        // hook's own package. Refused in draft and in publish mode, after the
-        // schema (so `body` is absent or a declared body) and before the
-        // authoring gate and every write. See {@link runtimeHookWithoutBodyRefusal}.
+        // [#21658, #21689] A hook that carries no `body` can never run once
+        // stored here, whether its `handler` names a function or it has
+        // neither field: a stored hook ships with no code package, so its
+        // `body` is the only code it can run. Refused in draft and in publish
+        // mode, after the schema (so `body` is absent or a declared body) and
+        // before the authoring gate and every write. See
+        // {@link runtimeHookWithoutBodyRefusal}.
         {
             const hookRefusal = runtimeHookWithoutBodyRefusal(singularType, request.item, request.name);
             if (hookRefusal) throw hookRefusal;
 
@@ -215,7 +215,8 @@ describe('#8421 — the traffic that must keep working', () => {
         {
             type: 'hook',
             why: 'declared, runtime-create only',
-            item: { name: 'probe_item', object: 'task', events: ['beforeUpdate'] },
+            // [#21689] With a `body`: the door refuses a hook without one.
+            item: { name: 'probe_item', object: 'task', events: ['beforeUpdate'], body: { language: 'js', source: 'return;' } },
         },
         {
             // `theme` held this slot until commit 35ad101bc retired the themes surface
 
@@ -143,12 +143,17 @@ const FIXTURES: Record<string, Fixture> = {
         invalidatedField: 'type',
     },
     hook: {
+        // [#21689] Both carry a `body`: the save door refuses a hook with no
+        // `body` (it could never run), so a body-less `valid` would measure
+        // that refusal, and `invalid` stays `valid` minus the one field the
+        // schema must name.
         valid: {
             name: 'sweep_hook',
             object: 'sweep_account',
             events: ['beforeInsert'],
+            body: { language: 'js', source: 'return;' },
         },
-        invalid: { name: 'sweep_hook', object: 'sweep_account' },
+        invalid: { name: 'sweep_hook', object: 'sweep_account', body: { language: 'js', source: 'return;' } },
         invalidatedField: 'events',
     },
     validation: {
Original file line number	Diff line number	Diff line change
`@@ -215,7 +215,8 @@ describe('#8421 — the traffic that must keep working', () => {`
`215`	`215`	`{`
`216`	`216`	`type: 'hook',`
`217`	`217`	`why: 'declared, runtime-create only',`
`218`		`- item: { name: 'probe_item', object: 'task', events: ['beforeUpdate'] },`
	`218`	+ // [#21689] With a `body`: the door refuses a hook without one.
	`219`	`+ item: { name: 'probe_item', object: 'task', events: ['beforeUpdate'], body: { language: 'js', source: 'return;' } },`
`219`	`220`	`},`
`220`	`221`	`{`
`221`	`222`	// `theme` held this slot until commit 35ad101bc retired the themes surface