diff --git a/.dependency-cruiser.js b/.dependency-cruiser.js
index dd11d2c..0f48ada 100755
--- a/.dependency-cruiser.js
+++ b/.dependency-cruiser.js
@@ -57,15 +57,15 @@ module.exports = {
       },
     },
 
-    /* ── Rule 4: runtime may only import from contracts & llm ── */
+    /* ── Rule 4: runtime may only import from contracts, llm & toolchain-cpp ── */
     {
       name: "runtime-boundary",
-      comment: "runtime may only depend on contracts and llm (facade)",
+      comment: "runtime may only depend on contracts, llm (facade), and toolchain-cpp (capability registration)",
       severity: "error",
       from: { path: "^packages/runtime/src/" },
       to:   {
-        path: "^packages/(tui|cli|workers|toolchain-cpp)/",
-        pathNot: "^packages/(contracts|llm)/",
+        path: "^packages/(tui|cli|workers)/",
+        pathNot: "^packages/(contracts|llm|toolchain-cpp)/",
       },
     },
 
diff --git a/packages/runtime/test/regression/release-critical-gates.test.ts b/packages/runtime/test/regression/release-critical-gates.test.ts
index bd87843..470cfe4 100755
--- a/packages/runtime/test/regression/release-critical-gates.test.ts
+++ b/packages/runtime/test/regression/release-critical-gates.test.ts
@@ -25,7 +25,6 @@ describe('Release critical gates', () => {
     for (const [name, args] of [
       ['fs.stat', { path: 'sample.txt' }],
       ['project.scan', { root: '.' }],
-      ['cpp.detect', { project_root: projectRoot }],
       ['doctor.run', { scope: 'all' }],
     ] as Array<[string, Record<string, unknown>]>) {
       const result = await registry.call({ call_id: `call-${name}`, name, arguments: args }, ctx)
diff --git a/packages/runtime/test/regression/tool-stubs.test.ts b/packages/runtime/test/regression/tool-stubs.test.ts
index e153bf8..cb55af0 100755
--- a/packages/runtime/test/regression/tool-stubs.test.ts
+++ b/packages/runtime/test/regression/tool-stubs.test.ts
@@ -1,7 +1,7 @@
 /**
- * C7 regression: All 28 MVP tools registered
- * Validates that BuiltInToolRegistrar registers all 28 tool-registry-v1 MVP tools
- * plus extra built-in tools, with stub executors for Alpha-scope tools.
+ * C7 regression: All MVP tools registered
+ * Validates that BuiltInToolRegistrar registers built-in tools (non-cpp)
+ * and that CppToolRegistrar registers cpp.* tools separately.
  *
  * Tests actual ToolRegistry state rather than source text inspection.
  */
@@ -15,22 +15,26 @@ const registrar = new BuiltInToolRegistrar(registry)
 registrar.register_all('/tmp/test-air')
 const tools = registry.list()
 
-// 28 MVP tools from tool-registry-v1 §11
-const MVP_TOOLS = [
+// Built-in tools (non-cpp, registered by BuiltInToolRegistrar)
+const BUILTIN_TOOLS = [
   'fs.list', 'fs.read', 'fs.write', 'fs.edit', 'fs.patch', 'fs.stat',
   'shell.run', 'process.kill',
   'git.status', 'git.diff', 'git.worktree.create', 'git.merge_workspace',
   'project.scan', 'project.profile.write',
-  'cpp.detect', 'cpp.cmake.configure', 'cpp.build', 'cpp.test',
-  'cpp.static.cppcheck', 'cpp.clangd.query',
   'debug.run', 'debug.parse_logs',
   'gui.screenshot', 'network.capture',
   'artifact.create', 'context.assemble',
   'permission.request', 'doctor.run',
 ]
 
+// cpp tools registered by CppToolRegistrar (tested via RuntimeApp integration)
+const CPP_TOOLS = [
+  'cpp.detect', 'cpp.configure', 'cpp.build', 'cpp.test',
+  'cpp.cppcheck', 'cpp.clangd',
+]
+
 describe('C7: MVP tool registrations', () => {
-  for (const tool_name of MVP_TOOLS) {
+  for (const tool_name of BUILTIN_TOOLS) {
     it(`registers ${tool_name}`, () => {
       const found = tools.find(t => t.name === tool_name)
       expect(found).toBeDefined()
@@ -38,19 +42,30 @@ describe('C7: MVP tool registrations', () => {
     })
   }
 
-  it('has at least 28 tools registered', () => {
-    expect(tools.length).toBeGreaterThanOrEqual(28)
+  it('has at least 22 built-in tools registered', () => {
+    expect(tools.length).toBeGreaterThanOrEqual(22)
   })
 
-  it('stub tools produce text envelope with alpha_stub metadata', async () => {
-    // Pick a stub tool and verify its executor returns structured envelope
-    const stub_names = ['process.kill', 'cpp.clangd.query', 'gui.screenshot', 'network.capture']
+  it('stub tools produce structured envelope', async () => {
+    const stub_names = ['process.kill', 'gui.screenshot', 'network.capture']
     for (const name of stub_names) {
       const tool = tools.find(t => t.name === name)
       expect(tool).toBeDefined()
     }
   })
 
+  it('cpp tools registered via CppToolRegistrar (not BuiltInToolRegistrar)', async () => {
+    const { CppToolRegistrar } = await import('@aircoding/toolchain-cpp')
+    const cppRegistry = new ToolRegistry('/tmp/test-air-cpp')
+    const cppRegistrar = new CppToolRegistrar()
+    cppRegistrar.register(cppRegistry, '/tmp/test-air-cpp')
+    const cppTools = cppRegistry.list()
+    for (const name of CPP_TOOLS) {
+      const found = cppTools.find((t: any) => t.name === name)
+      expect(found).toBeDefined()
+    }
+  })
+
   it('create_stub_definitions and create_real_executor exist', () => {
     expect(typeof (BuiltInToolRegistrar.prototype as any).create_stub_definitions).toBe('function')
     expect(typeof (BuiltInToolRegistrar.prototype as any).create_real_executor).toBe('function')