diff --git a/.objectui-sha b/.objectui-sha
index 2f1a4d2778..11870b052c 100644
--- a/.objectui-sha
+++ b/.objectui-sha
@@ -1 +1 @@
-e95cc25b2c0d2fa680e232151721e71c19630659
+76c38108544dd92abf965c0e07b0e4d92264708a
diff --git a/packages/services/service-ai/src/__tests__/chatbot-features.test.ts b/packages/services/service-ai/src/__tests__/chatbot-features.test.ts
index 93afbfdb33..39a9324b69 100644
--- a/packages/services/service-ai/src/__tests__/chatbot-features.test.ts
+++ b/packages/services/service-ai/src/__tests__/chatbot-features.test.ts
@@ -619,6 +619,24 @@ describe('AgentRuntime', () => {
         expect(messages[0].content).not.toContain('publish AUTOMATICALLY');
       }
     });
+
+    it('constrains to data-only when the authoring (build) skills are absent', () => {
+      // Open single-env framework: no AI Studio plugin → no authoring skills.
+      const messages = runtime.buildSystemMessages(DATA_CHAT_AGENT, undefined, [
+        { name: 'data_explorer', label: 'Data Explorer', tools: [] } as never,
+      ]);
+      expect(messages[0].content).toContain('BUILDING / AUTHORING is NOT available');
+      expect(messages[0].content).toContain('do NOT design or');
+    });
+
+    it('drops the data-only constraint when an authoring skill is active', () => {
+      // Cloud / EE: AI Studio plugin registered metadata_authoring → full build UX.
+      const messages = runtime.buildSystemMessages(DATA_CHAT_AGENT, undefined, [
+        { name: 'data_explorer', label: 'Data Explorer', tools: [] } as never,
+        { name: 'metadata_authoring', label: 'Metadata Authoring', tools: [] } as never,
+      ]);
+      expect(messages[0].content).not.toContain('BUILDING / AUTHORING is NOT available');
+    });
   });
 
   describe('buildRequestOptions', () => {
diff --git a/packages/services/service-ai/src/agent-runtime.ts b/packages/services/service-ai/src/agent-runtime.ts
index 286f92dd6d..4eef869bf2 100644
--- a/packages/services/service-ai/src/agent-runtime.ts
+++ b/packages/services/service-ai/src/agent-runtime.ts
@@ -160,6 +160,34 @@ export class AgentRuntime {
       if (block) parts.push(block);
     }
 
+    // Authoring (build) register availability. The unified `data_chat` persona
+    // (ADR-0040) advertises that it can BUILD or CHANGE the application, but
+    // that capability is supplied ENTIRELY by the cloud AI Studio plugin's
+    // `metadata_authoring` / `solution_design` skills (and their tools). On the
+    // open single-env framework those skills are not registered, so the
+    // authoring tools never resolve — yet the LLM, still reading the "you can
+    // build" persona, will role-play designing a whole system (emitting design
+    // docs it has no tools to execute). When the build register is absent,
+    // constrain the assistant to data/query and have it decline build requests
+    // instead of pretending. Keyed off actual skill presence so cloud/EE
+    // (AI Studio loaded) keeps the full build UX with no extra wiring.
+    const buildRegisterActive = !!activeSkills?.some(
+      (s) => s.name === 'metadata_authoring' || s.name === 'solution_design',
+    );
+    if (!buildRegisterActive) {
+      parts.push(
+        '\n--- Capabilities in this deployment ---\n' +
+          'Application BUILDING / AUTHORING is NOT available here. You can ONLY answer questions ' +
+          "about the user's existing data (query, list, count, aggregate, search) and run actions " +
+          'the application already exposes. You CANNOT create, change, or design objects, fields, ' +
+          'views, dashboards, pages, or whole apps — and you have no tools to do so. If the user ' +
+          'asks you to build, create, develop, or modify the application itself, do NOT design or ' +
+          'outline a system and do NOT pretend to build one: briefly say that AI app-building is ' +
+          'not available in this edition, then offer to help explore or report on existing data ' +
+          "instead. Answer in the user's language.",
+      );
+    }
+
     return [{ role: 'system' as const, content: parts.join('\n') }];
   }