diff --git a/.changeset/12055-upload-path-not-scope.md b/.changeset/12055-upload-path-not-scope.md
index bdbfcab3db..768f93fe56 100644
--- a/.changeset/12055-upload-path-not-scope.md
+++ b/.changeset/12055-upload-path-not-scope.md
@@ -6,7 +6,7 @@
 
 The adapter used to send `scope: opts.scope ?? options.path` in its presigned upload request, so an adapter built without a `scope` turned the `path` a caller passed to `upload(file, { path })` into the scope. A path is a key prefix for the S3 and Azure presign callbacks, not a scope: the ObjectStack storage service accepts only the values of the `scope` select on its `sys_file` object and refuses any other, so such an upload failed at the presign step. The adapter now sends only the `scope` it was built with, or none, and the server applies its default. `UploadResult.meta.scope` reports the same value.
 
-The `scope` option's documentation no longer teaches free key prefixes ("avatars", "logos", "attachments/case"). It names the server's `sys_file` scope select as the vocabulary. The option's type is unchanged (`string`).
+The `scope` option's documentation no longer teaches free key prefixes ("avatars", "logos", "attachments/case"). It names the server's `sys_file` scope select as the vocabulary.
 
 BREAKING (`@object-ui/providers`), for a caller that relied on `path` to choose the scope of an adapter built without one: the upload is now filed under the server's default scope. Remedy: pass one of the server's scopes as the adapter's `scope`, or none to take the server's default. (The bump is `minor` by this repo's release model: objectui's major follows the `@objectstack` family major, and its own breaking changes ship as `minor` with the breaking semantics stated here.)
 
diff --git a/.changeset/12055-upload-scope-type.md b/.changeset/12055-upload-scope-type.md
new file mode 100644
index 0000000000..4b211858ae
--- /dev/null
+++ b/.changeset/12055-upload-scope-type.md
@@ -0,0 +1,11 @@
+---
+'@object-ui/providers': minor
+---
+
+`createObjectStackUploadAdapter`'s `scope` option is typed from the spec's upload-scope vocabulary (objectui#12055).
+
+`ObjectStackUploadAdapterOptions.scope` was an open `string`, so a caller could build an adapter with a scope the ObjectStack storage service refuses with `400`. It is now `UploadScope` from `@objectstack/spec/api`, the one list the spec's upload request, the `scope` select on `sys_file` and the upload doors share. `@object-ui/providers` reaches it through the `API` namespace `@object-ui/types` already re-exports, so no dependency and no export is added. Omitting `scope` still sends none, and the server applies the default the spec's upload request declares.
+
+BREAKING (`@object-ui/providers`), TypeScript only, for a caller that builds the adapter with a scope outside the vocabulary (for example `'avatars'` or `'attachments/case'`): it no longer compiles. The server already refused such a request at runtime. Remedy: pass one of the vocabulary's values, or omit `scope` to take the server's default. (The bump is `minor` by this repo's release model: objectui's major follows the `@objectstack` family major, and its own breaking changes ship as `minor` with the breaking semantics stated here.)
+
+**Clause-②: no (narrowing)**: the option's accepted values narrow from any string to the spec's upload scopes. No export, option or type member is added; the declaration file gains a type-only import of `API` from `@object-ui/types`, a package `@object-ui/providers` already depends on.
diff --git a/packages/providers/src/UploadProvider.tsx b/packages/providers/src/UploadProvider.tsx
index 75953289c0..67799d8331 100644
--- a/packages/providers/src/UploadProvider.tsx
+++ b/packages/providers/src/UploadProvider.tsx
@@ -27,6 +27,7 @@ import React, {
   useRef,
   type ReactNode,
 } from 'react';
+import type { API } from '@object-ui/types';
 
 export interface UploadResult {
   /** Canonical, shareable URL (e.g. https://my-bucket.s3.amazonaws.com/avatars/abc.png). */
@@ -204,14 +205,17 @@ export interface ObjectStackUploadAdapterOptions {
   /**
    * The storage scope the server files every upload from this adapter
    * under, sent as the presigned upload request's `scope`. It is not a key
-   * prefix or folder. The server accepts only the values of the `scope`
-   * select on its `sys_file` object (`@objectstack/service-storage`) and
-   * refuses any other value; `attachments`, for example, is the scope of
-   * files joined to records through `sys_attachment`. Omit it and the
-   * request carries no scope, so the server applies its default
-   * (objectui#12055).
+   * prefix or folder. Its values are the spec's upload-scope vocabulary,
+   * `UploadScope` from `@objectstack/spec/api` (reached here as
+   * `API.UploadScope` from `@object-ui/types`): the one list the upload
+   * request, the `scope` select on `sys_file` and the upload doors share.
+   * A value outside it does not compile, and the server refuses it with
+   * `400`. `attachments`, for example, is the scope of files joined to
+   * records through `sys_attachment`. Omit it and the request carries no
+   * scope, so the server applies the default the spec's upload request
+   * declares (objectui#12055).
    */
-  scope?: string;
+  scope?: API.UploadScope;
   /** Override `fetch` (tests, ServiceWorker queues). */
   fetchImpl?: typeof fetch;
   /**
diff --git a/packages/providers/src/__tests__/objectstack-upload-scope-12055.test.ts b/packages/providers/src/__tests__/objectstack-upload-scope-12055.test.ts
index d430d585c4..0ca8947304 100644
--- a/packages/providers/src/__tests__/objectstack-upload-scope-12055.test.ts
+++ b/packages/providers/src/__tests__/objectstack-upload-scope-12055.test.ts
@@ -17,11 +17,17 @@
  *
  * These pins read the presign request body the adapter actually sends,
  * through an injected `fetchImpl` (no global is replaced).
+ *
+ * The option's TYPE is the spec's upload-scope vocabulary, `UploadScope` from
+ * `@objectstack/spec/api`, reached through `@object-ui/types`'s `API`
+ * namespace. The compile-time pins at the end of this file are checked by
+ * `tsconfig.test.json`, which `type-check` chains after the source program.
  */
 
 import { describe, it, expect } from 'vitest';
+import type { API } from '@object-ui/types';
 
-import { createObjectStackUploadAdapter } from '../UploadProvider';
+import { createObjectStackUploadAdapter, type ObjectStackUploadAdapterOptions } from '../UploadProvider';
 
 const FILE_ID = 'f-12055';
 
@@ -105,3 +111,39 @@ describe('the in-repo upload shapes send the same request as before (objectui#12
     });
   });
 });
+
+/* -------------------------------------------------------------------------- */
+/* Compile-time pins — compiled by tsconfig.test.json, chained off type-check. */
+/* -------------------------------------------------------------------------- */
+
+type Assert<T extends true> = T;
+type Equal<A, B> = (<T>() => T extends A ? 1 : 2) extends <T>() => T extends B ? 1 : 2 ? true : false;
+type IsAny<T> = 0 extends 1 & T ? true : false;
+
+describe("the scope option is typed from the spec's upload-scope vocabulary (objectui#12055)", () => {
+  it('is the spec type itself: not a free string, not a local copy', () => {
+    type Scope = NonNullable<ObjectStackUploadAdapterOptions['scope']>;
+    // The spec type resolved (an unresolved import would read as `any` and
+    // make every pin below vacuous).
+    type _SpecTypeIsReal = Assert<Equal<IsAny<API.UploadScope>, false>>;
+    // Exactly the spec's type: a member the spec adds or retires moves the
+    // option with it, and no consumer-side list can drift from it.
+    type _OptionIsTheSpecType = Assert<Equal<Scope, API.UploadScope>>;
+    // Not widened back to an open string.
+    type _NotAnOpenString = Assert<Equal<string extends Scope ? true : false, false>>;
+
+    expect(true).toBe(true);
+  });
+
+  it("refuses a scope outside the vocabulary at the authoring site: 'avatars' does not compile", () => {
+    // The pin is this directive: with `scope` widened to `string` the line
+    // compiles, the directive goes unused, and `type-check` fails (TS2578).
+    // @ts-expect-error -- 'avatars' is a key prefix, not an upload scope; the server refuses it with 400.
+    const refused: ObjectStackUploadAdapterOptions = { scope: 'avatars' };
+    void refused;
+    // The in-repo producer's value compiles (RecordAttachmentsPanel builds its adapter with it).
+    const accepted: ObjectStackUploadAdapterOptions = { scope: 'attachments' };
+
+    expect(accepted.scope).toBe('attachments');
+  });
+});