diff --git a/packages/downstream-contract/src/additional-domains.fixtures.ts b/packages/downstream-contract/src/additional-domains.fixtures.ts
new file mode 100644
index 0000000000..c61d9993c8
--- /dev/null
+++ b/packages/downstream-contract/src/additional-domains.fixtures.ts
@@ -0,0 +1,151 @@
+// Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
+
+// FROZEN bare-literal fixtures for the remaining authoring domains (#2035), so
+// the downstream contract exercises the FULL writable surface, not just a few
+// domains. Authored the way a third party on a published release did, typed with
+// the spec's own input aliases. DO NOT migrate these to the defineX factories
+// and DO NOT edit them to make a failing spec change pass — see the README.
+import type { DatasourceInput, MappingInput, CubeInput, ObjectExtensionInput } from '@objectstack/spec/data';
+import type { ConnectorInput } from '@objectstack/spec/integration';
+import type { PolicyInput, SharingRuleInput, PermissionSetInput } from '@objectstack/spec/security';
+import type { RoleInput } from '@objectstack/spec/identity';
+import type { EmailTemplateDefinitionInput, TranslationBundleInput } from '@objectstack/spec/system';
+import type { WebhookInput } from '@objectstack/spec/automation';
+import type { ThemeInput } from '@objectstack/spec/ui';
+
+export const DcDatasource: DatasourceInput = {
+  name: 'dc_primary',
+  label: 'DC Primary',
+  driver: 'sqlite',
+  config: { filename: ':memory:' },
+  active: true,
+};
+
+export const DcConnector: ConnectorInput = {
+  name: 'dc_hubspot',
+  label: 'DC HubSpot',
+  type: 'saas',
+  description: 'Example SaaS connector.',
+  authentication: {
+    type: 'oauth2',
+    authorizationUrl: 'https://example.com/oauth/authorize',
+    tokenUrl: 'https://example.com/oauth/token',
+    clientId: 'env:DC_CLIENT_ID',
+    clientSecret: 'env:DC_CLIENT_SECRET',
+  },
+  actions: [
+    {
+      key: 'create_contact',
+      label: 'Create Contact',
+      description: 'Create a contact',
+      inputSchema: { type: 'object', properties: { email: { type: 'string' } }, required: ['email'] },
+    },
+  ],
+};
+
+export const DcPolicy: PolicyInput = {
+  name: 'dc_default_policy',
+  isDefault: true,
+  password: { minLength: 12, requireUppercase: true, requireNumbers: true },
+  session: { idleTimeout: 30, absoluteTimeout: 480 },
+};
+
+export const DcSharingRule: SharingRuleInput = {
+  type: 'criteria',
+  name: 'dc_share_customers',
+  label: 'Customers → managers',
+  object: 'dc_account',
+  condition: 'record.stage == "customer"',
+  accessLevel: 'read',
+  sharedWith: { type: 'role', value: 'dc_manager' },
+  active: true,
+};
+
+export const DcRole: RoleInput = {
+  name: 'dc_manager',
+  label: 'DC Manager',
+  description: 'Manager role.',
+};
+
+export const DcPermissionSet: PermissionSetInput = {
+  name: 'dc_user',
+  label: 'DC User',
+  isProfile: false,
+  objects: {
+    dc_account: { allowRead: true, allowCreate: true, allowEdit: true, allowDelete: false },
+  },
+};
+
+export const DcEmail: EmailTemplateDefinitionInput = {
+  name: 'dc.welcome',
+  label: 'DC Welcome',
+  category: 'marketing',
+  locale: 'en-US',
+  subject: 'Welcome {{contact.first_name}}',
+  bodyHtml: '<p>Hi {{contact.first_name}}, welcome.</p>',
+  bodyText: 'Hi {{contact.first_name}}, welcome.',
+  variables: [{ name: 'contact.first_name', type: 'string', required: true }],
+  active: true,
+};
+
+export const DcWebhook: WebhookInput = {
+  name: 'dc_account_changed',
+  label: 'Account Changed',
+  object: 'dc_account',
+  triggers: ['create', 'update'],
+  url: 'https://hooks.example.com/dc/account',
+  method: 'POST',
+  isActive: true,
+};
+
+export const DcObjectExtension: ObjectExtensionInput = {
+  extend: 'dc_account',
+  label: 'Account (extended)',
+  fields: {
+    note: { name: 'note', label: 'Note', type: 'text', maxLength: 255 },
+  },
+  priority: 210,
+};
+
+export const DcCube: CubeInput = {
+  name: 'dc_pipeline',
+  title: 'DC Pipeline',
+  description: 'Account analytics.',
+  sql: 'dc_account',
+  measures: {
+    count: { name: 'count', label: 'Count', type: 'count', sql: '*' },
+  },
+  dimensions: {
+    stage: { name: 'stage', label: 'Stage', type: 'string', sql: 'stage' },
+  },
+};
+
+export const DcMapping: MappingInput = {
+  name: 'dc_csv_import',
+  label: 'CSV Import: Accounts',
+  sourceFormat: 'csv',
+  targetObject: 'dc_account',
+  mode: 'upsert',
+  upsertKey: ['name'],
+  fieldMapping: [{ source: 'Name', target: 'name', transform: 'none' }],
+};
+
+export const DcTheme: ThemeInput = {
+  name: 'dc_light',
+  label: 'DC Light',
+  mode: 'light',
+  colors: {
+    primary: '#1E6FD9',
+    secondary: '#6C757D',
+    background: '#FFFFFF',
+    surface: '#F8F9FA',
+    text: '#212529',
+  },
+};
+
+export const DcTranslationBundle: TranslationBundleInput = {
+  en: {
+    objects: { dc_account: { label: 'Account', pluralLabel: 'Accounts' } },
+    messages: { 'common.save': 'Save' },
+  },
+};
diff --git a/packages/downstream-contract/test/contract.test.ts b/packages/downstream-contract/test/contract.test.ts
index cde669ad18..364353d053 100644
--- a/packages/downstream-contract/test/contract.test.ts
+++ b/packages/downstream-contract/test/contract.test.ts
@@ -1,11 +1,18 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
 import { describe, it, expect } from 'vitest';
-import { ActionSchema, ReportSchema, PageSchema } from '@objectstack/spec/ui';
+import { ActionSchema, ReportSchema, PageSchema, ThemeSchema } from '@objectstack/spec/ui';
+import { DatasourceSchema, MappingSchema, CubeSchema, ObjectExtensionSchema } from '@objectstack/spec/data';
+import { ConnectorSchema } from '@objectstack/spec/integration';
+import { PolicySchema, SharingRuleSchema, PermissionSetSchema } from '@objectstack/spec/security';
+import { RoleSchema } from '@objectstack/spec/identity';
+import { EmailTemplateDefinitionSchema, TranslationBundleSchema } from '@objectstack/spec/system';
+import { WebhookSchema } from '@objectstack/spec/automation';
 import { LogCallAction } from '../src/log-call.action.js';
 import { AccountsByStageReport } from '../src/pipeline.report.js';
 import { WelcomePage } from '../src/welcome.page.js';
 import { ContractStack } from '../src/stack.js';
+import * as more from '../src/additional-domains.fixtures.js';
 
 // FROZEN — see README. A failure means a spec change dropped or narrowed a
 // property a published-spec third party already uses. That is breaking: adjust
@@ -22,4 +29,26 @@ describe('downstream consumer contract (#2035)', () => {
     expect(ContractStack.objects).toHaveLength(1);
     expect(ContractStack.actions).toHaveLength(2);
   });
+
+  // Full writable-surface coverage: one frozen bare-literal per remaining domain
+  // (#2035). A narrowed/removed schema property on ANY of these breaks here.
+  const cases: Array<[string, { parse: (v: unknown) => unknown }, unknown]> = [
+    ['Datasource', DatasourceSchema, more.DcDatasource],
+    ['Connector', ConnectorSchema, more.DcConnector],
+    ['Policy', PolicySchema, more.DcPolicy],
+    ['SharingRule', SharingRuleSchema, more.DcSharingRule],
+    ['Role', RoleSchema, more.DcRole],
+    ['PermissionSet', PermissionSetSchema, more.DcPermissionSet],
+    ['EmailTemplateDefinition', EmailTemplateDefinitionSchema, more.DcEmail],
+    ['Webhook', WebhookSchema, more.DcWebhook],
+    ['ObjectExtension', ObjectExtensionSchema, more.DcObjectExtension],
+    ['Cube', CubeSchema, more.DcCube],
+    ['Mapping', MappingSchema, more.DcMapping],
+    ['Theme', ThemeSchema, more.DcTheme],
+    ['TranslationBundle', TranslationBundleSchema, more.DcTranslationBundle],
+  ];
+
+  it.each(cases)('%s bare-literal parses against the current spec', (_name, schema, fixture) => {
+    expect(() => schema.parse(fixture)).not.toThrow();
+  });
 });