diff --git a/builtins/project/dotgitignore b/builtins/project/dotgitignore
index ef5b653..576c437 100644
--- a/builtins/project/dotgitignore
+++ b/builtins/project/dotgitignore
@@ -6,16 +6,17 @@
 
 # Project configuration
 !config.yaml
-!.takt/
-!.takt/pieces/
-!.takt/pieces/**
-!.takt/personas/
-!.takt/personas/**
-!.takt/policies/
-!.takt/policies/**
-!.takt/knowledge/
-!.takt/knowledge/**
-!.takt/instructions/
-!.takt/instructions/**
-!.takt/output-contracts/
-!.takt/output-contracts/**
+
+# Facets and pieces (version-controlled)
+!pieces/
+!pieces/**
+!personas/
+!personas/**
+!policies/
+!policies/**
+!knowledge/
+!knowledge/**
+!instructions/
+!instructions/**
+!output-contracts/
+!output-contracts/**
diff --git a/src/__tests__/it-dotgitignore.test.ts b/src/__tests__/it-dotgitignore.test.ts
new file mode 100644
index 0000000..10adada
--- /dev/null
+++ b/src/__tests__/it-dotgitignore.test.ts
@@ -0,0 +1,98 @@
+/**
+ * Integration test for dotgitignore
+ *
+ * Verifies that .takt/.gitignore patterns correctly track facet directories
+ * (pieces, personas, policies, knowledge, instructions, output-contracts)
+ * while ignoring runtime directories (tasks, logs, runs, completed).
+ */
+
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { mkdirSync, writeFileSync, rmSync, existsSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { execFileSync } from 'node:child_process';
+import { tmpdir } from 'node:os';
+
+function gitTrackedFiles(cwd: string): string[] {
+  const output = execFileSync('git', ['ls-files', '.takt/'], { cwd, encoding: 'utf-8' });
+  return output.trim().split('\n').filter(Boolean).sort();
+}
+
+describe('dotgitignore patterns', () => {
+  let testDir: string;
+
+  beforeEach(() => {
+    testDir = join(tmpdir(), `takt-dotgitignore-${Date.now()}`);
+    mkdirSync(testDir, { recursive: true });
+
+    execFileSync('git', ['init'], { cwd: testDir });
+    execFileSync('git', ['config', 'user.name', 'Test User'], { cwd: testDir });
+    execFileSync('git', ['config', 'user.email', 'test@example.com'], { cwd: testDir });
+
+    // Initial commit
+    writeFileSync(join(testDir, 'README.md'), '# Test');
+    execFileSync('git', ['add', '.'], { cwd: testDir });
+    execFileSync('git', ['commit', '-m', 'Initial commit'], { cwd: testDir });
+
+    // Copy actual dotgitignore as .takt/.gitignore
+    const dotgitignorePath = join(__dirname, '..', '..', 'builtins', 'project', 'dotgitignore');
+    const taktDir = join(testDir, '.takt');
+    mkdirSync(taktDir, { recursive: true });
+    const content = readFileSync(dotgitignorePath, 'utf-8');
+    writeFileSync(join(taktDir, '.gitignore'), content);
+  });
+
+  afterEach(() => {
+    if (existsSync(testDir)) {
+      rmSync(testDir, { recursive: true, force: true });
+    }
+  });
+
+  it('should track config.yaml', () => {
+    writeFileSync(join(testDir, '.takt', 'config.yaml'), 'language: ja\n');
+    execFileSync('git', ['add', '.takt/'], { cwd: testDir });
+
+    const tracked = gitTrackedFiles(testDir);
+    expect(tracked).toContain('.takt/config.yaml');
+  });
+
+  it('should track facet directories', () => {
+    const facets = ['pieces', 'personas', 'policies', 'knowledge', 'instructions', 'output-contracts'];
+    for (const facet of facets) {
+      mkdirSync(join(testDir, '.takt', facet), { recursive: true });
+      writeFileSync(join(testDir, '.takt', facet, 'test.md'), `# ${facet}`);
+    }
+
+    execFileSync('git', ['add', '.takt/'], { cwd: testDir });
+    const tracked = gitTrackedFiles(testDir);
+
+    for (const facet of facets) {
+      expect(tracked).toContain(`.takt/${facet}/test.md`);
+    }
+  });
+
+  it('should track nested files in facet directories', () => {
+    mkdirSync(join(testDir, '.takt', 'pieces', 'sub'), { recursive: true });
+    writeFileSync(join(testDir, '.takt', 'pieces', 'sub', 'nested.yaml'), 'name: test');
+
+    execFileSync('git', ['add', '.takt/'], { cwd: testDir });
+    const tracked = gitTrackedFiles(testDir);
+
+    expect(tracked).toContain('.takt/pieces/sub/nested.yaml');
+  });
+
+  it('should ignore runtime directories', () => {
+    const runtimeDirs = ['tasks', 'completed', 'logs', 'runs'];
+    for (const dir of runtimeDirs) {
+      mkdirSync(join(testDir, '.takt', dir), { recursive: true });
+      writeFileSync(join(testDir, '.takt', dir, 'data.json'), '{}');
+    }
+
+    execFileSync('git', ['add', '.takt/'], { cwd: testDir });
+    const tracked = gitTrackedFiles(testDir);
+
+    for (const dir of runtimeDirs) {
+      const runtimeFiles = tracked.filter(f => f.startsWith(`.takt/${dir}/`));
+      expect(runtimeFiles).toEqual([]);
+    }
+  });
+});