diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..d987275
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,24 @@
+# CI 基线（任务 A1.2 先接入依赖方向检查；lint 与完整测试矩阵见 A1.6）
+name: ci
+
+on:
+  push:
+    branches: [rewrite/platform, main]
+  pull_request:
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: pnpm/action-setup@v4
+        with:
+          version: 11
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22.19.0'
+          cache: pnpm
+      - run: pnpm install --frozen-lockfile
+      - run: pnpm typecheck
+      - run: pnpm check:deps
+      - run: pnpm test
\ No newline at end of file
diff --git a/package.json b/package.json
index ed48657..85285ab 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,9 @@
   "scripts": {
     "typecheck": "tsc -b",
     "build": "tsc -b",
-    "clean": "tsc -b --clean"
+    "clean": "tsc -b --clean",
+    "check:deps": "node scripts/check-dependency-direction.mjs",
+    "test": "node --test \"scripts/**/*.test.mjs\""
   },
   "devDependencies": {
     "typescript": "^7.0.2"
diff --git a/scripts/check-dependency-direction.mjs b/scripts/check-dependency-direction.mjs
new file mode 100644
index 0000000..fef8825
--- /dev/null
+++ b/scripts/check-dependency-direction.mjs
@@ -0,0 +1,176 @@
+#!/usr/bin/env node
+/**
+ * 依赖方向检查（任务 A1.2）。
+ *
+ * 拦三类反向依赖：
+ *   1. 包之间越界——core 引用具体 Provider、业务包直连 Provider、客户端引用服务端
+ *   2. 相对路径逃出包边界
+ *   3. 引擎包被 server/agent 之外的模块引用（ADR-0006）
+ *
+ * 用法：node scripts/check-dependency-direction.mjs [仓库根目录]
+ * 退出码 0 = 无违规，1 = 有违规。
+ */
+import { existsSync } from 'node:fs';
+import { readFile, readdir, stat } from 'node:fs/promises';
+import { dirname, join, relative, resolve, sep } from 'node:path';
+import process from 'node:process';
+import { pathToFileURL } from 'node:url';
+
+/** 包 → 允许依赖的包。新增包必须在这里登记，否则视为违规。 */
+export const PACKAGE_RULES = {
+  '@aps/contracts': { allow: [] },
+  '@aps/provider-sdk': { allow: ['@aps/contracts'] },
+  '@aps/server': { allow: ['@aps/contracts', '@aps/provider-sdk'] },
+  '@aps/client-app': { allow: ['@aps/contracts'] },
+  '@aps/desktop': { allow: ['@aps/contracts', '@aps/client-app'] },
+  '@aps/provider-aps': { allow: ['@aps/contracts', '@aps/provider-sdk'] },
+};
+
+/** 引擎包：只有 server/agent 允许引用（ADR-0006）。 */
+export const ENGINE_PACKAGES = ['@earendil-works/pi-agent-core', '@earendil-works/pi-ai'];
+
+const ENGINE_ALLOWED_PREFIX = 'server/agent/';
+const SOURCE_EXTENSIONS = new Set(['.ts', '.tsx', '.mts', '.cts', '.js', '.mjs', '.cjs']);
+const SKIP_DIRS = new Set(['node_modules', 'dist', '.git', 'coverage', '__pycache__']);
+
+async function workspacePatterns(root) {
+  const file = join(root, 'pnpm-workspace.yaml');
+  if (!existsSync(file)) throw new Error(`未找到 ${file}`);
+  const text = await readFile(file, 'utf8');
+  const patterns = [];
+  for (const line of text.split(/\r?\n/)) {
+    const trimmed = line.trim();
+    if (trimmed.startsWith('- ')) patterns.push(trimmed.slice(2).trim().replace(/^['"]|['"]$/g, ''));
+  }
+  return patterns;
+}
+
+export async function workspacePackages(root) {
+  const dirs = [];
+  for (const pattern of await workspacePatterns(root)) {
+    if (pattern.includes('*')) {
+      const base = pattern.replace(/\/\*+$/, '');
+      const entries = await readdir(join(root, base), { withFileTypes: true }).catch(() => []);
+      for (const entry of entries) if (entry.isDirectory()) dirs.push(`${base}/${entry.name}`);
+    } else {
+      dirs.push(pattern);
+    }
+  }
+  return [...new Set(dirs)];
+}
+
+async function collectSources(dir, nestedRoots, acc = []) {
+  let entries;
+  try {
+    entries = await readdir(dir, { withFileTypes: true });
+  } catch {
+    return acc;
+  }
+  for (const entry of entries) {
+    const full = join(dir, entry.name);
+    if (entry.isDirectory()) {
+      if (SKIP_DIRS.has(entry.name)) continue;
+      if (nestedRoots.has(full)) continue; // 嵌套包由它自己那轮检查
+      await collectSources(full, nestedRoots, acc);
+    } else if (SOURCE_EXTENSIONS.has(entry.name.slice(entry.name.lastIndexOf('.')))) {
+      acc.push(full);
+    }
+  }
+  return acc;
+}
+
+function extractSpecifiers(text) {
+  const found = new Set();
+  const patterns = [
+    /(?:^|[^\w$.])import\s+(?:[^'";]*?\sfrom\s+)?['"]([^'"]+)['"]/g,
+    /import\s*\(\s*['"]([^'"]+)['"]\s*\)/g,
+    /require\s*\(\s*['"]([^'"]+)['"]\s*\)/g,
+  ];
+  for (const pattern of patterns) {
+    let match;
+    while ((match = pattern.exec(text)) !== null) found.add(match[1]);
+  }
+  return [...found];
+}
+
+const allowText = (rule) => (rule.allow.length ? rule.allow.join('、') : '无');
+
+/** 返回违规清单；空数组表示通过。 */
+export async function findViolations(root) {
+  const packages = await workspacePackages(root);
+  const nestedRoots = new Set(packages.map((rel) => join(root, rel)));
+  const violations = [];
+
+  for (const rel of packages) {
+    const pkgDir = join(root, rel);
+    const manifestPath = join(pkgDir, 'package.json');
+    if (!existsSync(manifestPath)) {
+      violations.push({ package: rel, file: `${rel}/package.json`, specifier: '', reason: '工作区目录缺少 package.json' });
+      continue;
+    }
+    const manifest = JSON.parse(await readFile(manifestPath, 'utf8'));
+    const name = manifest.name ?? rel;
+    const rule = PACKAGE_RULES[name];
+    if (!rule) {
+      violations.push({ package: name, file: `${rel}/package.json`, specifier: '', reason: '未登记的包名：先在 PACKAGE_RULES 里写明它允许依赖谁' });
+      continue;
+    }
+
+    const declared = [
+      ...Object.keys(manifest.dependencies ?? {}),
+      ...Object.keys(manifest.devDependencies ?? {}),
+      ...Object.keys(manifest.peerDependencies ?? {}),
+    ];
+    for (const dep of declared) {
+      if (dep.startsWith('@aps/') && dep !== name && !rule.allow.includes(dep)) {
+        violations.push({ package: name, file: `${rel}/package.json`, specifier: dep, reason: `声明了不允许的依赖（允许：${allowText(rule)}）` });
+      }
+    }
+
+    for (const file of await collectSources(pkgDir, nestedRoots)) {
+      const relFile = relative(root, file).split(sep).join('/');
+      const text = await readFile(file, 'utf8');
+      for (const specifier of extractSpecifiers(text)) {
+        if (specifier.startsWith('@aps/')) {
+          if (specifier === name) continue;
+          if (!rule.allow.includes(specifier)) {
+            violations.push({ package: name, file: relFile, specifier, reason: `不允许引用该包（允许：${allowText(rule)}）` });
+          }
+          continue;
+        }
+        const engineHit = ENGINE_PACKAGES.find((pkg) => specifier === pkg || specifier.startsWith(`${pkg}/`));
+        if (engineHit) {
+          if (!relFile.startsWith(ENGINE_ALLOWED_PREFIX)) {
+            violations.push({ package: name, file: relFile, specifier, reason: `引擎包只能由 ${ENGINE_ALLOWED_PREFIX} 引用（ADR-0006）` });
+          }
+          continue;
+        }
+        if (specifier.startsWith('.')) {
+          const target = resolve(dirname(file), specifier);
+          const inside = target === pkgDir || target.startsWith(pkgDir + sep);
+          if (!inside) violations.push({ package: name, file: relFile, specifier, reason: '相对路径逃出包边界' });
+        }
+      }
+    }
+  }
+  return violations;
+}
+
+async function main() {
+  const root = resolve(process.argv[2] ?? process.cwd());
+  if (!(await stat(root)).isDirectory()) throw new Error(`${root} 不是目录`);
+  const violations = await findViolations(root);
+  if (violations.length === 0) {
+    console.log(`依赖方向检查通过（根目录：${root}）`);
+    return;
+  }
+  console.error(`依赖方向检查发现 ${violations.length} 处违规：`);
+  for (const v of violations) {
+    console.error(`  [${v.package}] ${v.file}${v.specifier ? ` → ${v.specifier}` : ''}：${v.reason}`);
+  }
+  process.exitCode = 1;
+}
+
+if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
+  await main();
+}
\ No newline at end of file
diff --git a/scripts/check-dependency-direction.test.mjs b/scripts/check-dependency-direction.test.mjs
new file mode 100644
index 0000000..7e54ed6
--- /dev/null
+++ b/scripts/check-dependency-direction.test.mjs
@@ -0,0 +1,122 @@
+/**
+ * 依赖方向检查的负例用例（任务 A1.2 的验证方式）。
+ * 每个负例都要求检查器真的报错——只测正例等于没测。
+ */
+import assert from 'node:assert/strict';
+import { mkdtemp, mkdir, rm, writeFile } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { dirname, join } from 'node:path';
+import { test } from 'node:test';
+import { fileURLToPath } from 'node:url';
+
+import { findViolations } from './check-dependency-direction.mjs';
+
+const REPO_ROOT = fileURLToPath(new URL('..', import.meta.url));
+
+const WORKSPACE = ['contracts', 'server', 'server/provider-sdk', 'providers/*', 'client/*'];
+
+/** 造一个最小工作区；extra 覆盖或新增文件（键为相对路径）。 */
+async function makeWorkspace(extra = {}) {
+  const root = await mkdtemp(join(tmpdir(), 'depcheck-'));
+  const files = {
+    'pnpm-workspace.yaml': `packages:\n${WORKSPACE.map((p) => `  - ${p}\n`).join('')}`,
+    'contracts/package.json': JSON.stringify({ name: '@aps/contracts' }),
+    'server/package.json': JSON.stringify({ name: '@aps/server', dependencies: { '@aps/contracts': 'workspace:*', '@aps/provider-sdk': 'workspace:*' } }),
+    'server/provider-sdk/package.json': JSON.stringify({ name: '@aps/provider-sdk', dependencies: { '@aps/contracts': 'workspace:*' } }),
+    'providers/aps/package.json': JSON.stringify({ name: '@aps/provider-aps', dependencies: { '@aps/provider-sdk': 'workspace:*' } }),
+    'client/app/package.json': JSON.stringify({ name: '@aps/client-app', dependencies: { '@aps/contracts': 'workspace:*' } }),
+    ...extra,
+  };
+  for (const [rel, content] of Object.entries(files)) {
+    const file = join(root, rel);
+    await mkdir(dirname(file), { recursive: true });
+    await writeFile(file, content, 'utf8');
+  }
+  return root;
+}
+
+async function withWorkspace(extra, run) {
+  const root = await makeWorkspace(extra);
+  try {
+    return await run(root);
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+}
+
+const reasons = (violations) => violations.map((v) => `${v.file} → ${v.specifier}：${v.reason}`).join('\n');
+
+test('正例：当前仓库无违规', async () => {
+  assert.deepEqual(await findViolations(REPO_ROOT), []);
+});
+
+test('负例：core 引用具体 Provider 被拦下', async () => {
+  await withWorkspace(
+    {
+      'server/core/router.ts': "import type { CapabilityProvider } from '@aps/provider-aps';\nexport type X = CapabilityProvider;\n",
+    },
+    async (root) => {
+      const violations = await findViolations(root);
+      assert.ok(violations.some((v) => v.file.endsWith('server/core/router.ts') && v.specifier === '@aps/provider-aps'), reasons(violations));
+    },
+  );
+});
+
+test('负例：业务包直连 Provider 被拦下', async () => {
+  await withWorkspace(
+    { 'client/app/direct.ts': "import '@aps/provider-aps';\n" },
+    async (root) => {
+      const violations = await findViolations(root);
+      assert.ok(violations.some((v) => v.package === '@aps/client-app' && v.specifier === '@aps/provider-aps'), reasons(violations));
+    },
+  );
+});
+
+test('负例：客户端引用服务端被拦下', async () => {
+  await withWorkspace(
+    { 'client/app/server-call.ts': "import type { ExecutionReceipt } from '@aps/server';\nexport type R = ExecutionReceipt;\n" },
+    async (root) => {
+      const violations = await findViolations(root);
+      assert.ok(violations.some((v) => v.specifier === '@aps/server'), reasons(violations));
+    },
+  );
+});
+
+test('负例：非 agent 模块引用引擎包被拦下', async () => {
+  await withWorkspace(
+    { 'server/entry/boot.ts': "import '@earendil-works/pi-agent-core';\n" },
+    async (root) => {
+      const violations = await findViolations(root);
+      assert.ok(violations.some((v) => v.file.endsWith('server/entry/boot.ts')), reasons(violations));
+    },
+  );
+});
+
+test('正例：server/agent 引用引擎包放行', async () => {
+  await withWorkspace(
+    { 'server/agent/runtime.ts': "import '@earendil-works/pi-agent-core';\n" },
+    async (root) => {
+      assert.deepEqual(await findViolations(root), []);
+    },
+  );
+});
+
+test('负例：相对路径逃出包边界被拦下', async () => {
+  await withWorkspace(
+    { 'client/app/escape.ts': "import '../../../providers/aps/index.js';\n" },
+    async (root) => {
+      const violations = await findViolations(root);
+      assert.ok(violations.some((v) => v.reason === '相对路径逃出包边界'), reasons(violations));
+    },
+  );
+});
+
+test('负例：未登记的包名被拦下', async () => {
+  await withWorkspace(
+    { 'providers/erp/package.json': JSON.stringify({ name: '@aps/provider-erp' }) },
+    async (root) => {
+      const violations = await findViolations(root);
+      assert.ok(violations.some((v) => v.reason.includes('未登记的包名')), reasons(violations));
+    },
+  );
+});
\ No newline at end of file