diff --git a/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.i18n.yaml b/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.i18n.yaml
index 90f4d0e145..f922fdaa95 100644
--- a/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.i18n.yaml
+++ b/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.md
-2026-08-10-source-run-without-managed-installer.md: 35f0c705731147ce8bb64c2e985789aff341996c
-2026-08-10-source-run-without-managed-installer.zh.md: 51b336f4c399ebfd24f499288eee477bed9f23cb
+2026-08-10-source-run-without-managed-installer.md: ecc4530b90a495f210476f100e894a7ce77cdb63
+2026-08-10-source-run-without-managed-installer.zh.md: 940bc6245bacc91abea4e2c746d81dbce4a50105
diff --git a/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.md b/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.md
index 35f0c70573..ecc4530b90 100644
--- a/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.md
+++ b/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.md
@@ -12,7 +12,7 @@ That lifecycle is not required to run or develop DeepSeek Harness from a source
 
 ## Decision
 
-The repository supports source execution through its root `pnpm` scripts. The `pnpm dsh <args...>` script runs the complete repository build before launching the source CLI; users select Web with `pnpm dsh web` and headless execution with `pnpm dsh run`. The independent ACP example remains available through `pnpm run demo:acp`.
+The repository supports source execution through its root `pnpm` scripts. The `pnpm dsh <args...>` launcher runs the complete repository build before launching the source CLI. It discards successful build output so CLI stdout remains machine-readable, reports failed build diagnostics on stderr, and sets `NODE_USE_ENV_PROXY=1` for the CLI process. Users select Web with `pnpm dsh web` and headless execution with `pnpm dsh run`. The independent ACP example remains available through `pnpm run demo:acp`.
 
 The repository does not distribute a source installer, an installer test suite, or skills that assume a managed `current` symlink and timestamped staging worktrees. Users own source checkout placement, Git updates, and any launcher they create outside the repository.
 
@@ -28,4 +28,4 @@ The repository does not distribute a source installer, an installer test suite,
 
 Source users invoke repository scripts rather than an installed `dsh` command. The repository provides no atomic upgrade cutover or preserved staging rollback checkout, and it does not automate the integration or upstream publication of personal source modifications. A future distribution mechanism must justify its ownership of installation and upgrade state, define recovery behavior, and add tests and user documentation without making the source-run path depend on it. Any future publication workflow must isolate one approved feature and obtain explicit approval before its first push and draft PR.
 
-Verification covers repository-wide references to the removed entry points, documentation links, generated third-party-notice freshness, and a clean-artifact source CLI smoke through `pnpm dsh`.
+Verification covers repository-wide references to the removed entry points, documentation links, generated third-party-notice freshness, and source CLI smokes that verify the build-first launch and absence of build logs on stdout through `pnpm dsh`.
diff --git a/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.zh.md b/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.zh.md
index 51b336f4c3..940bc6245b 100644
--- a/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.zh.md
+++ b/.agents/notes/implemented/simplification/2026-08-10-source-run-without-managed-installer.zh.md
@@ -12,7 +12,7 @@ Status: implemented
 
 ## 决策
 
-仓库通过根目录的 `pnpm` 脚本支持从源码运行。`pnpm dsh <args...>` 脚本会先完成整个仓库的构建，再启动源码 CLI（命令行界面）；用户使用 `pnpm dsh web` 选择 Web，使用 `pnpm dsh run` 选择无头执行。独立的 ACP（Agent Client Protocol）示例仍可通过 `pnpm run demo:acp` 运行。
+仓库通过根目录的 `pnpm` 脚本支持从源码运行。`pnpm dsh <args...>` 启动器会先完成整个仓库的构建，再启动源码 CLI（命令行界面）。它会丢弃成功构建的输出，使 CLI stdout 保持机器可读；在 stderr 中报告构建失败的诊断信息；并为 CLI 进程设置 `NODE_USE_ENV_PROXY=1`。用户使用 `pnpm dsh web` 选择 Web，使用 `pnpm dsh run` 选择无头执行。独立的 ACP（Agent Client Protocol）示例仍可通过 `pnpm run demo:acp` 运行。
 
 仓库不分发源码安装器、安装器测试套件，也不分发依赖受管理的 `current` 符号链接和带时间戳 staging worktree 的 skill。源码检出的存放位置、Git 更新，以及用户在仓库外创建的任何启动器均由用户负责。
 
@@ -28,4 +28,4 @@ Status: implemented
 
 源码用户通过仓库脚本运行程序，而非使用已安装的 `dsh` 命令。仓库不提供原子升级切换，也不保留 staging 回滚检出；仓库同样不会自动集成个人源码修改或将其发布到上游。未来的分发机制必须说明为何应由其管理安装和升级状态，定义恢复行为，并补充测试与用户文档，同时不得让源码运行路径依赖该机制。未来任何发布工作流都必须隔离出一项获批功能，并在首次推送和创建草稿 PR（Pull Request）前取得明确批准。
 
-验证范围包括仓库内对已移除入口点的所有引用、文档链接、生成的第三方声明文件的新鲜度，以及在无构建产物状态下通过 `pnpm dsh` 启动源码 CLI 的冒烟测试。
+验证范围包括仓库内对已移除入口点的所有引用、文档链接、生成的第三方声明文件的新鲜度，以及通过 `pnpm dsh` 对源码 CLI 进行冒烟测试，验证先构建后启动且 stdout 不含构建日志。
diff --git a/apps/cli/tests/source-launch.compat.spec.ts b/apps/cli/tests/source-launch.compat.spec.ts
index 5d92d021f0..68b4f73158 100644
--- a/apps/cli/tests/source-launch.compat.spec.ts
+++ b/apps/cli/tests/source-launch.compat.spec.ts
@@ -16,6 +16,22 @@ const repoRoot = fileURLToPath(new URL('../../../', import.meta.url))
 const dshSourceBin = 'apps/cli/src/bin.ts'
 
 describe('dsh SOURCE launcher (node --import tsx/esm)', () => {
+  it('builds without mixing build logs into CLI stdout', async () => {
+    const result = await execa('pnpm', ['dsh', '--help'], {
+      cwd: repoRoot,
+      timeout: 120_000,
+      killSignal: 'SIGKILL',
+      reject: false,
+    })
+    if (result.timedOut) {
+      throw new Error(`pnpm dsh --help did not exit within 120s. stdout:\n${result.stdout}\nstderr:\n${result.stderr}`)
+    }
+    expect(result.exitCode).toBe(0)
+    expect(result.stdout).toMatch(/^Usage: dsh /)
+    expect(result.stdout).not.toContain('tsdown')
+    expect(result.stdout).not.toContain('build:lib')
+  }, 125_000)
+
   it('boots the source entry and requires a profile', async () => {
     const result = await execa(process.execPath, ['--import', 'tsx/esm', dshSourceBin], {
       cwd: repoRoot,
diff --git a/docs/user/guide/quickstart.i18n.yaml b/docs/user/guide/quickstart.i18n.yaml
index 83eea0ed76..f6c6096f40 100644
--- a/docs/user/guide/quickstart.i18n.yaml
+++ b/docs/user/guide/quickstart.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/user/guide/quickstart.md
-quickstart.md: 540eed86bc83e70f3a9724f601fd71170996ce0b
-quickstart.zh.md: ab529333eb3c62add8cf422328b0ba838efc82e6
+quickstart.md: f6537c71fc94096b2daf49827d041979346632bb
+quickstart.zh.md: fbecabb964e3786929b3b942f49b5b44a4437e05
diff --git a/docs/user/guide/quickstart.md b/docs/user/guide/quickstart.md
index 540eed86bc..f6537c71fc 100644
--- a/docs/user/guide/quickstart.md
+++ b/docs/user/guide/quickstart.md
@@ -19,10 +19,9 @@ pnpm -v
 ## Step 1: install and configure the API key
 
 ```sh
-git clone https://github.com/deepseek-ai/deepseek-harness-sdk.git
+git clone https://github.com/deepseek-ai/deepseek-harness-sdk.git deepseek-harness
 cd deepseek-harness
 pnpm install
-pnpm run build
 ```
 
 Create the gitignored repository-root `.env`:
diff --git a/docs/user/guide/quickstart.zh.md b/docs/user/guide/quickstart.zh.md
index ab529333eb..fbecabb964 100644
--- a/docs/user/guide/quickstart.zh.md
+++ b/docs/user/guide/quickstart.zh.md
@@ -19,10 +19,9 @@ pnpm -v
 ## 第一步：安装并配置 API 密钥
 
 ```sh
-git clone https://github.com/deepseek-ai/deepseek-harness-sdk.git
+git clone https://github.com/deepseek-ai/deepseek-harness-sdk.git deepseek-harness
 cd deepseek-harness
 pnpm install
-pnpm run build
 ```
 
 在仓库根目录创建已被 Git 忽略的 `.env`：
diff --git a/package.json b/package.json
index 4acd724112..d34d3322b2 100644
--- a/package.json
+++ b/package.json
@@ -127,7 +127,7 @@
     "release:pack": "tsx scripts/release/pack.ts",
     "release:verify-packed-install": "tsx scripts/release/verify-packed-install.ts",
     "release:publish": "tsx scripts/release/publish.ts",
-    "dsh": "npm run build && node --import tsx/esm apps/cli/src/bin.ts",
+    "dsh": "tsx scripts/run-source-dsh.ts",
     "demo:code-mode": "node scripts/demo-code-mode.mjs",
     "demo:cordis": "node scripts/demo-cordis.mjs",
     "demo:acp": "node --import tsx packages/examples/acp-demo/src/bin.ts --config examples/acp-agent/cordis.yml",
diff --git a/scripts/run-source-dsh.ts b/scripts/run-source-dsh.ts
new file mode 100644
index 0000000000..3d97a44faa
--- /dev/null
+++ b/scripts/run-source-dsh.ts
@@ -0,0 +1,48 @@
+/**
+ * Source-checkout launcher. Successful build output stays out of CLI stdout;
+ * build failures report their captured diagnostics on stderr before exiting.
+ */
+import process from 'node:process'
+import { fileURLToPath } from 'node:url'
+
+import { execa } from 'execa'
+
+const repoRoot = fileURLToPath(new URL('..', import.meta.url))
+const sourceBin = fileURLToPath(new URL('../apps/cli/src/bin.ts', import.meta.url))
+
+function completeFrom(result: { readonly exitCode?: number; readonly signal?: string }): void {
+  if (result.signal !== undefined) {
+    process.kill(process.pid, result.signal)
+    return
+  }
+  process.exitCode = result.exitCode ?? 1
+}
+
+function reportBuildFailure(result: {
+  readonly all: string | undefined
+  readonly shortMessage: string | undefined
+}): void {
+  const diagnostic = result.all === undefined || result.all.length === 0
+    ? result.shortMessage ?? 'Source build failed without diagnostics.'
+    : result.all
+  process.stderr.write(diagnostic.endsWith('\n') ? diagnostic : `${diagnostic}\n`)
+}
+
+const build = await execa('pnpm', ['run', 'build'], {
+  all: true,
+  cwd: repoRoot,
+  reject: false,
+  stripFinalNewline: false,
+})
+if (build.failed) {
+  reportBuildFailure(build)
+  completeFrom(build)
+} else {
+  const cli = await execa(process.execPath, ['--import', 'tsx/esm', sourceBin, ...process.argv.slice(2)], {
+    cwd: repoRoot,
+    env: { ...process.env, NODE_USE_ENV_PROXY: '1' },
+    reject: false,
+    stdio: 'inherit',
+  })
+  completeFrom(cli)
+}