@@ -0,0 +1,30 @@
+---
+'@object-ui/types': minor
+---
+
+Publish the derived strict authoring face from `@object-ui/types/zod`
+(objectui#8345, under the objectui#5250 ruling — maintainer 2026-09-04,
+decision batch #25, option 2: "each node schema gets a derived strict variant;
+`objectui validate` and the doc-snippet gates run strict; renderer props keep
+the tolerant face unchanged").
+
+**Additive. No existing accept set moves.** `BaseSchema` keeps its
+`.passthrough()`, every published mirror keeps the documents it accepts today,
+and no consumer in this repository is wired to the new face — wiring
+`objectui validate` and the JSON-fence gate is a separate card. What is new:
+
+- `StrictAnyComponentSchema` — the document-root twin of `AnyComponentSchema`,
+  refusing any undeclared key at any depth with an `unrecognized_keys` issue
+  that names it.
+- `StrictSchemaNodeSchema` — the child-slot twin of `SchemaNodeSchema`.
+- `deriveStrictAuthoringSchema(schema, options)` — the derivation itself, so a
+  consumer can take the strict twin of any schema on the face rather than
+  writing a second walker.
+
+The twins are **derived**, never hand-written: every reachable object is closed
+through unions, discriminated unions, arrays, tuples, records, intersections,
+optionals, nullables, defaults, both sides of a pipe, and `z.lazy`. Objects are
+cloned by patching a copy of their own def, so `.refine()` and `.superRefine()`
+checks survive — a twin rebuilt with `z.object(shape)` would drop them and
+under-report. Opaque `custom` / `function` / `transform` validators have no
+shape to close and are reported through `onOpaqueShape` rather than skipped.
@@ -121,6 +121,42 @@ function renderComponent(schema: AnySchema) {
 type ButtonSchema = SchemaByType<'button'>;
 ```
 
+### The strict authoring face
+
+`@object-ui/types/zod` publishes **two** faces over the same declarations.
+
+- The **rendering face** (`AnyComponentSchema`, `SchemaNodeSchema`, every named
+  mirror) is tolerant: a node may carry keys the schema does not declare, because
+  renderer props ride through it.
+- The **strict authoring face** is a derived twin that closes every declared
+  object, at every depth. It is meant for authoring-time checking — validating a
+  document a person or an agent just wrote — where an undeclared key is far more
+  likely to be a typo than a renderer prop.
+
+```typescript
+import {
+  AnyComponentSchema,
+  ButtonSchema,
+  StrictAnyComponentSchema,
+  deriveStrictAuthoringSchema,
+} from '@object-ui/types/zod';
+
+const document = { type: 'card', childrn: [] }; // note the typo
+
+AnyComponentSchema.safeParse(document).success;       // true  — the tolerant face
+StrictAnyComponentSchema.safeParse(document).success; // false — `unrecognized_keys: ["childrn"]`
+
+// Take the strict twin of any schema on the face:
+const StrictButton = deriveStrictAuthoringSchema(ButtonSchema);
+```
+
+The twins are derived from the mirrors, never hand-written, so they cannot drift
+from them. Strictness here is a property of the parse, not of the declaration:
+the derived schema carries the same TypeScript type as the schema it came from.
+Opaque `custom` / `function` / `transform` validators have no shape to close;
+`deriveStrictAuthoringSchema` reports each one it meets through the optional
+`onOpaqueShape` callback.
+
 ## Type Categories
 
 ### Base Types