diff --git a/lib/permissions/minimally-encoded-thread-permissions.js b/lib/permissions/minimally-encoded-thread-permissions.js
--- a/lib/permissions/minimally-encoded-thread-permissions.js
+++ b/lib/permissions/minimally-encoded-thread-permissions.js
@@ -9,8 +9,11 @@
   ThreadPermissionsInfo,
   ThreadRolePermissionsBlob,
 } from '../types/thread-permission-types.js';
-import type { RoleInfo } from '../types/thread-types.js';
-import { roleInfoValidator } from '../types/thread-types.js';
+import type { RoleInfo, ThreadCurrentUserInfo } from '../types/thread-types.js';
+import {
+  roleInfoValidator,
+  threadCurrentUserInfoValidator,
+} from '../types/thread-types.js';
 import { entries, invertObjectToMap } from '../utils/objects.js';
 import { tRegex, tShape } from '../utils/validation-utils.js';
 import type { TRegex } from '../utils/validation-utils.js';
@@ -196,6 +199,18 @@
     permissions: t.list(tHexEncodedRolePermission),
   });
 
+export type MinimallyEncodedThreadCurrentUserInfo = {
+  ...ThreadCurrentUserInfo,
+  +permissions: string,
+};
+
+const tHexEncodedPermissionsBitmask: TRegex = tRegex(/^[0-9a-fA-F]+$/);
+const minimallyEncodedThreadCurrentUserInfoValidator: TInterface<MinimallyEncodedThreadCurrentUserInfo> =
+  tShape<MinimallyEncodedThreadCurrentUserInfo>({
+    ...threadCurrentUserInfoValidator.meta.props,
+    permissions: tHexEncodedPermissionsBitmask,
+  });
+
 export {
   permissionsToBitmaskHex,
   hasPermission,
@@ -204,4 +219,5 @@
   threadRolePermissionsBlobToBitmaskArray,
   decodeThreadRolePermissionsBitmaskArray,
   minimallyEncodedRoleInfoValidator,
+  minimallyEncodedThreadCurrentUserInfoValidator,
 };
diff --git a/lib/permissions/minimally-encoded-thread-permissions.test.js b/lib/permissions/minimally-encoded-thread-permissions.test.js
--- a/lib/permissions/minimally-encoded-thread-permissions.test.js
+++ b/lib/permissions/minimally-encoded-thread-permissions.test.js
@@ -5,6 +5,7 @@
   decodeThreadRolePermissionsBitmaskArray,
   hasPermission,
   minimallyEncodedRoleInfoValidator,
+  minimallyEncodedThreadCurrentUserInfoValidator,
   permissionsToBitmaskHex,
   rolePermissionToBitmaskHex,
   threadRolePermissionsBlobToBitmaskArray,
@@ -282,3 +283,43 @@
     ).toBe(false);
   });
 });
+
+describe('minimallyEncodedThreadCurrentUserInfoValidator', () => {
+  it('should validate correctly formed MinimallyEncodedThreadCurrentUserInfo', () => {
+    expect(
+      minimallyEncodedThreadCurrentUserInfoValidator.is({
+        permissions: '100',
+        subscription: { home: true, pushNotifs: true },
+      }),
+    ).toBe(true);
+    expect(
+      minimallyEncodedThreadCurrentUserInfoValidator.is({
+        permissions: 'ABCDEFABCDEFABCD',
+        subscription: { home: true, pushNotifs: true },
+      }),
+    ).toBe(true);
+  });
+
+  it('should NOT validate malformed MinimallyEncodedThreadCurrentUserInfo', () => {
+    expect(
+      minimallyEncodedThreadCurrentUserInfoValidator.is({
+        permissions: 'INVALID',
+        subscription: { home: true, pushNotifs: true },
+      }),
+    ).toBe(false);
+
+    expect(
+      minimallyEncodedThreadCurrentUserInfoValidator.is({
+        permissions: 'ABCDEF  hello  ABCDEFABCD',
+        subscription: { home: true, pushNotifs: true },
+      }),
+    ).toBe(false);
+
+    expect(
+      minimallyEncodedThreadCurrentUserInfoValidator.is({
+        permissions: 100,
+        subscription: { home: true, pushNotifs: true },
+      }),
+    ).toBe(false);
+  });
+});
diff --git a/lib/types/thread-types.js b/lib/types/thread-types.js
--- a/lib/types/thread-types.js
+++ b/lib/types/thread-types.js
@@ -78,12 +78,13 @@
   +subscription: ThreadSubscription,
   +unread: ?boolean,
 };
-const threadCurrentUserInfoValidator = tShape<ThreadCurrentUserInfo>({
-  role: t.maybe(tID),
-  permissions: threadPermissionsInfoValidator,
-  subscription: threadSubscriptionValidator,
-  unread: t.maybe(t.Boolean),
-});
+export const threadCurrentUserInfoValidator: TInterface<ThreadCurrentUserInfo> =
+  tShape<ThreadCurrentUserInfo>({
+    role: t.maybe(tID),
+    permissions: threadPermissionsInfoValidator,
+    subscription: threadSubscriptionValidator,
+    unread: t.maybe(t.Boolean),
+  });
 
 export type RawThreadInfo = {
   +id: string,