@@ -0,0 +1,29 @@
+---
+'@objectstack/spec': minor
+'@objectstack/metadata-protocol': minor
+'@objectstack/objectql': minor
+'@objectstack/client': minor
+---
+
+feat(spec): a hook can tell the person who saved a record what the save set in motion
+
+Clause-②: yes
+Metadata-protocol: added
+
+A `beforeInsert` / `beforeUpdate` / `afterInsert` / `afterUpdate` hook had no way to tell the person saving what the save started, such as sending a deal for approval. The single-record write answer carried `warnings` (advisory validation-rule hits) and nothing else a save could say. Now a hook can attach one message to the save's answer.
+
+- **Spec.** `CreateDataResponseSchema` and `UpdateDataResponseSchema` declare an optional, response-only `notice`: one author-written message, info severity, separate from `warnings`. When more than one call sets it, the last one wins. The key is omitted when no hook set one, and it is never stored on the record. `WriteObservabilityOptions` declares the in-process listener a hook calls to set it, `onNotice(message)`, beside `onFieldsDropped`, `onValidationAdvisory` and `onMentionsWithheld`. Like them it never crosses the wire.
+- **metadata-protocol.** `createData` and `updateData` pass the listener and answer the last non-empty message as `notice`. A nested write that a hook or a flow makes inside this one carries its own options, so its notice never reaches this answer.
+- **client.** `CreateDataResult` and `UpdateDataResult` declare `notice?: string`, mirroring the two schemas.
+- **objectql.** `engine.update` accepts the `onNotice` option. The engine never calls it; it carries it to the hooks with the rest of the caller's bag.
+
+How a hook sets it: read the write's own options bag off `ctx.input.options` and call the listener when it is there.
+
+```ts
+const opts = ctx.input.options as WriteObservabilityOptions | undefined;
+opts?.onNotice?.('Sent to your manager for approval');
+```
+
+A hook whose handler runs as code in the server process (registered with `registerHook`, or a declarative `handler` bound as a function) can call it today. A hook that runs in the sandbox (a `body`, including a `handler` the build lowers into one) cannot yet, and neither can a record-triggered flow: both are follow-up work.
+
+Nothing to do for existing clients: a client that does not read `notice` sees the same answer as before.
@@ -239,6 +239,13 @@ the requester's own answer only. The comment is saved
 with every mention, and nothing about the withheld users is stored on it. With
 nobody withheld, the key is absent.
 
+When a hook on the write tells the person who saved what the save set in motion
+("Sent to your manager for approval"), the answer also carries `notice`: that one
+author-written message, info severity, separate from `warnings`. Show it with, or
+in place of, your own success message. If more than one hook sets it, the last one
+wins. A hook on a nested write never reaches it, nothing about it is stored, and
+with no notice set the key is absent.
+
 ### `PATCH /data/:object/:id`
 
 Update an existing record (partial update).
@@ -249,6 +256,8 @@ Update an existing record (partial update).
 A `sys_comment` update answers `withheldMentions` the same way, for the mentions
 the update added. A mention the comment already carried is not judged again.
 
+It answers `notice` the same way as a create, when a hook on the update set one.
+
 ### `DELETE /data/:object/:id`
 
 Delete a record.
 
@@ -327,13 +327,15 @@ interface EngineUpdateOptions {
 
 ### WriteObservabilityOptions
 
-The write methods (`insert` / `update`) additionally accept four **in-process**
+The write methods (`insert` / `update`) additionally accept five **in-process**
 options. Two govern what happens when caller-supplied write fields are legally
 stripped from the payload before the driver write: observe the strip
 (`onFieldsDropped`) or refuse the write outright (`strictReadonlyWrites`). The
 third, `onValidationAdvisory`, reports the write's advisory validation-rule hits.
 The fourth, `onMentionsWithheld`, reports the users a comment write @mentioned who
 will not be notified.
+The fifth, `onNotice`, is how a hook tells the person who made the write what
+the save set in motion.
 
 The strips these two options cover are the engine's legal ones:
 
@@ -360,6 +362,7 @@ interface WriteObservabilityOptions {
   onFieldsDropped?: (event: DroppedFieldsEvent) => void;
   onValidationAdvisory?: (event: ValidationAdvisoryEvent) => void;
   onMentionsWithheld?: (userIds: readonly string[]) => void;
+  onNotice?: (message: string) => void;
   strictReadonlyWrites?: boolean;  // refuse instead of stripping. Default: false
 }
 
@@ -475,6 +478,40 @@ ids as `withheldMentions`, on the requester's own answer to that request only an
 least one user was withheld. Nothing is stored on the comment: a stored member
 would tell every reader of the comment who cannot read its thread.
 
+#### `onNotice` — what the save set in motion
+
+A hook that starts something the person saving should hear about ("Sent to your
+manager for approval") calls this listener with one author-written message. It is
+info severity: it reports an outcome, never a problem, so it is not a validation
+finding and never rides `onValidationAdvisory`. The engine never calls it. A hook
+reaches it the way every member of this bag reaches a hook, on
+`ctx.input.options`: a `before*` handler reads the caller's bag as passed, an
+`after*` handler after `buildDriverOptions` widened it.
+
+{/* os:check */}
+```typescript
+import type { HookContext } from '@objectstack/spec/data';
+import type { WriteObservabilityOptions } from '@objectstack/spec/contracts';
+
+export async function announceApproval(ctx: HookContext): Promise<void> {
+  const opts = ctx.input.options as WriteObservabilityOptions | undefined;
+  opts?.onNotice?.('Sent to your manager for approval');
+}
+```
+
+The listener is often absent (a seed, a flow node, a batch or an import passes
+none), so call it optionally. One message per write: a later call replaces an
+earlier one, and a message that is not a non-empty string sets nothing. A write
+that is refused answers its error, never a notice. A nested write that a hook or a
+flow makes inside this one carries its own options, so its notice never reaches
+this listener. The sandboxed `body` face (including a `handler` the build lowers
+into a body) does not carry it: its `ctx.input.options` is the frozen
+`{ multi, where }` projection.
+
+The DataProtocol's `createData` and `updateData` pass this listener and answer
+the message as `notice`, on the requester's own answer to that request only and
+present only when a hook set one. Nothing is stored on the record.
+
 <Callout type="warn">
 **Layering — this is the engine seam, and since the 2026-09-03 ruling the only
 one.** The DataProtocol create faces (`createData`, `cloneData`, `createManyData`,
@@ -486,7 +523,7 @@ declares one; none carries a `readonly` policy of its own any more — see
 
 <Callout type="warn">
 `WriteObservabilityOptions` is a **TS-contract-level, in-process-only** bag —
-all four members. It is deliberately not part of the serializable Zod options schemas:
+all five members. It is deliberately not part of the serializable Zod options schemas:
 a function is unrepresentable in JSON Schema and cannot be serialized, so remote
 callers (REST, the client SDK) never receive these events; and putting
 `strictReadonlyWrites` in the serializable bag would let any client toggle
 
@@ -557,6 +557,7 @@ A write-path strip event: caller-supplied fields legally dropped from the payloa
 | **droppedFields** | `{ object: string; fields: string[]; reason: Enum<'readonly' \| 'readonly_when' \| 'primary_key' \| 'computed' \| 'stored_expression'> }[]` | optional | Write-observability: caller-supplied fields that were LEGALLY stripped before the record was written — a non-system create cannot seed a static `readonly` column (the strip runs inside `engine.insert`, after the `beforeInsert` hooks, `isSystem`-gated), so those keys are dropped and the field re-derives its default. Present ONLY when ≥1 field was dropped; the create still succeeded without them (status/success semantics unchanged). REST additionally surfaces this as the `X-ObjectStack-Dropped-Fields` response header. Optional — omit-when-empty keeps the shape backward-compatible for existing clients. |
 | **warnings** | `{ field: string; code: string; message: string; rule?: string; … }[]` | optional | The advisory validation-rule hits of THIS write: each `severity: 'warning'` or `'info'` rule whose verdict on the written record was "violated", with its `rule` name, `severity`, `field`, `code` and author-written `message` — the same element the validate-only preview reports in a row's `warnings`. Advisory rules never block, so the write succeeded; this is the advisory to show the person who made it. Present ONLY when at least one advisory rule hit; a write with no hit omits the key. Hits of a nested write a hook or a flow made inside this one are not included, and a rule that could not be evaluated is not a hit. |
 | **withheldMentions** | `string[]` | optional | The ids of the users this write @mentioned whose mention notification was WITHHELD by the mention recipient gate, so they will not be notified: the gate's own verdict on THIS write, ids only, never the reason. Only a `sys_comment` write fills it, and only on the requester's own answer to the request that made the write; on an update, only a mention the update added is judged. The comment was saved with every mention; the requester is told here that the named users will not be notified. Response-only: never stored on the comment (a stored member would tell every reader who cannot read the thread). Present ONLY when at least one mention was withheld; otherwise the key is omitted. |
+| **notice** | `string` | optional | One author-written message telling the person who made THIS write what the save set in motion (for example "Sent to your manager for approval"), set by a hook running on the write through the write's own `onNotice` listener (`WriteObservabilityOptions`). Info severity: it reports an outcome, never a problem, so it is distinct from `warnings` (the advisory validation-rule hits) and a client shows it with, or in place of, its own success message. One message: when more than one call sets it, the LAST one wins. Present ONLY when a hook set a non-empty message on a write that succeeded; otherwise the key is omitted. A nested write a hook or a flow made inside this one carries its own options, so its notice never reaches this answer. Response-only: never stored on the record. |
 
 ### Nested Shape: `CreateDataResponse.droppedFields[number]`
 
@@ -3043,6 +3044,7 @@ Uninstall package response
 | **droppedFields** | `{ object: string; fields: string[]; reason: Enum<'readonly' \| 'readonly_when' \| 'primary_key' \| 'computed' \| 'stored_expression'> }[]` | optional | Write-observability: caller-supplied fields the engine LEGALLY stripped from the write before persisting — static `readonly` or a TRUE `readonlyWhen` predicate. Present ONLY when ≥1 field was dropped; the update still succeeded without them (status/success semantics unchanged — stripping is legitimate, not an error). REST additionally surfaces this as the `X-ObjectStack-Dropped-Fields` response header. Optional — omit-when-empty keeps the shape backward-compatible for existing clients that only read `record`. |
 | **warnings** | `{ field: string; code: string; message: string; rule?: string; … }[]` | optional | The advisory validation-rule hits of THIS write: each `severity: 'warning'` or `'info'` rule whose verdict on the written record was "violated", with its `rule` name, `severity`, `field`, `code` and author-written `message` — the same element the validate-only preview reports in a row's `warnings`. Advisory rules never block, so the write succeeded; this is the advisory to show the person who made it. Present ONLY when at least one advisory rule hit; a write with no hit omits the key. Hits of a nested write a hook or a flow made inside this one are not included, and a rule that could not be evaluated is not a hit. |
 | **withheldMentions** | `string[]` | optional | The ids of the users this write @mentioned whose mention notification was WITHHELD by the mention recipient gate, so they will not be notified: the gate's own verdict on THIS write, ids only, never the reason. Only a `sys_comment` write fills it, and only on the requester's own answer to the request that made the write; on an update, only a mention the update added is judged. The comment was saved with every mention; the requester is told here that the named users will not be notified. Response-only: never stored on the comment (a stored member would tell every reader who cannot read the thread). Present ONLY when at least one mention was withheld; otherwise the key is omitted. |
+| **notice** | `string` | optional | One author-written message telling the person who made THIS write what the save set in motion (for example "Sent to your manager for approval"), set by a hook running on the write through the write's own `onNotice` listener (`WriteObservabilityOptions`). Info severity: it reports an outcome, never a problem, so it is distinct from `warnings` (the advisory validation-rule hits) and a client shows it with, or in place of, its own success message. One message: when more than one call sets it, the LAST one wins. Present ONLY when a hook set a non-empty message on a write that succeeded; otherwise the key is omitted. A nested write a hook or a flow made inside this one carries its own options, so its notice never reaches this answer. Response-only: never stored on the record. |
 
 ### Nested Shape: `UpdateDataResponse.droppedFields[number]`
 
 
@@ -498,6 +498,14 @@ export interface CreateDataResult<T = any> {
    * comment. Present only when at least one mention was withheld.
    */
   withheldMentions?: string[];
+  /**
+   * [#28000] One author-written message a hook on this write set to tell the
+   * person who made it what the save set in motion (for example "Sent to your
+   * manager for approval"). Info severity, distinct from `warnings`: show it
+   * with, or in place of, your own success message. Present only when a hook
+   * set one; never stored on the record.
+   */
+  notice?: string;
 }
 
 /**
@@ -560,6 +568,14 @@ export interface UpdateDataResult<T = any> {
    * comment. Present only when at least one mention was withheld.
    */
   withheldMentions?: string[];
+  /**
+   * [#28000] One author-written message a hook on this write set to tell the
+   * person who made it what the save set in motion (for example "Sent to your
+   * manager for approval"). Info severity, distinct from `warnings`: show it
+   * with, or in place of, your own success message. Present only when a hook
+   * set one; never stored on the record.
+   */
+  notice?: string;
 }
 
 /**
 
@@ -13743,10 +13743,17 @@ export class ObjectStackProtocolImplementation implements
         // nor any other request's answer ever carries them, and nothing is
         // stored on the comment.
         const withheldMentions = new Set<string>();
+        // [#28000] The one message a hook on THIS write set to tell the
+        // requester what the save set in motion, answered as `notice`. The hook
+        // reads the listener off `ctx.input.options`, which is this bag, so a
+        // nested write's hook never reaches it; a later call replaces an
+        // earlier one, and anything but a non-empty string sets nothing.
+        let notice: string | undefined;
         const opts: any = {
             onFieldsDropped: (e: DroppedFieldsEvent) => { dropped.push(e); },
             onValidationAdvisory: (e: ValidationAdvisoryEvent) => { warnings.push(e); },
             onMentionsWithheld: (ids: readonly string[]) => { for (const id of ids) withheldMentions.add(id); },
+            onNotice: (message: unknown) => { if (typeof message === 'string' && message.trim() !== '') notice = message; },
         };
         if (request.context !== undefined) opts.context = request.context;
         const result = await this.engine.insert(request.object, request.data, opts);
@@ -13765,6 +13772,7 @@ export class ObjectStackProtocolImplementation implements
             ...(dropped.length > 0 ? { droppedFields: dropped } : {}),
             ...(warnings.length > 0 ? { warnings } : {}),
             ...(withheldMentions.size > 0 ? { withheldMentions: [...withheldMentions] } : {}),
+            ...(notice !== undefined ? { notice } : {}),
         };
     }
 
@@ -13917,6 +13925,9 @@ export class ObjectStackProtocolImplementation implements
         // answered as `withheldMentions` (see `createData`).
         const withheldMentions = new Set<string>();
         opts.onMentionsWithheld = (ids: readonly string[]) => { for (const id of ids) withheldMentions.add(id); };
+        // [#28000] The hook-set message answered as `notice` (see `createData`).
+        let notice: string | undefined;
+        opts.onNotice = (message: unknown) => { if (typeof message === 'string' && message.trim() !== '') notice = message; };
         // [#6479] At THIS ingress the row is the one the caller named — `request.id`,
         // the path `:id` — and nothing in the payload gets to move it.
         //
@@ -13994,6 +14005,7 @@ export class ObjectStackProtocolImplementation implements
             ...(dropped.length > 0 ? { droppedFields: dropped } : {}),
             ...(warnings.length > 0 ? { warnings } : {}),
             ...(withheldMentions.size > 0 ? { withheldMentions: [...withheldMentions] } : {}),
+            ...(notice !== undefined ? { notice } : {}),
         };
     }
 
 
@@ -200,6 +200,10 @@ describe('unknown engine option keys are rejected (#4371 option 2)', () => {
         await engine.update('task', { title: 'A5' }, { where: { id: a.id }, onMentionsWithheld: () => {} } as any);
     });
 
+    it('onNotice passes on update (contract-declared write observability, #28000)', async () => {
+        await engine.update('task', { title: 'A6' }, { where: { id: a.id }, onNotice: () => {} } as any);
+    });
+
     it('searchFields passes on find (read by the $search expansion)', async () => {
         // Legality pin only — the $or/$contains expansion itself is covered by
         // the search-filter tests; this mock driver does not evaluate it.
@@ -263,9 +267,10 @@ describe('unknown engine option keys are rejected (#4371 option 2)', () => {
         // this list must. Spelling it here is what keeps the engine from
         // rejecting a key the TS contract declares. [#22726]
         // `onValidationAdvisory` is the third such member.
-        // `onMentionsWithheld` (#27703) is the fourth: the engine only carries
-        // it to the `after*` hooks, on `ctx.input.options`.
-        expectSetMatches('update', EngineUpdateOptionsSchema as any, ['onFieldsDropped', 'onValidationAdvisory', 'onMentionsWithheld', 'strictReadonlyWrites', ...PASSTHROUGH]);
+        // `onMentionsWithheld` (#27703) is the fourth and `onNotice` (#28000)
+        // the fifth: the engine only carries them to the hooks, on
+        // `ctx.input.options`.
+        expectSetMatches('update', EngineUpdateOptionsSchema as any, ['onFieldsDropped', 'onValidationAdvisory', 'onMentionsWithheld', 'onNotice', 'strictReadonlyWrites', ...PASSTHROUGH]);
         expectSetMatches('delete', EngineDeleteOptionsSchema as any, PASSTHROUGH);
         expectSetMatches('count', EngineCountOptionsSchema as any, []);
         expectSetMatches('aggregate', EngineAggregateOptionsSchema as any, []);
 
@@ -716,7 +716,7 @@ const ENGINE_FIND_OPTION_KEYS: ReadonlySet<string> = new Set([
   ...ENGINE_DRIVER_PASSTHROUGH_KEYS,
 ]);
 const ENGINE_UPDATE_OPTION_KEYS: ReadonlySet<string> = new Set([
-  'context', 'where', 'multi', 'returning', 'onFieldsDropped', 'onValidationAdvisory', 'onMentionsWithheld', 'strictReadonlyWrites',
+  'context', 'where', 'multi', 'returning', 'onFieldsDropped', 'onValidationAdvisory', 'onMentionsWithheld', 'onNotice', 'strictReadonlyWrites',
   ...ENGINE_DRIVER_PASSTHROUGH_KEYS,
 ]);
 const ENGINE_DELETE_OPTION_KEYS: ReadonlySet<string> = new Set([