diff --git a/agent_reach/backends/__init__.py b/agent_reach/backends/__init__.py
new file mode 100644
index 0000000..fa7ff2d
--- /dev/null
+++ b/agent_reach/backends/__init__.py
@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+"""Cross-channel backends.
+
+A backend here is an upstream runtime that serves MULTIPLE channels
+(e.g. OpenCLI covers xiaohongshu/reddit/bilibili/twitter through one
+browser session), as opposed to the per-platform tools probed inside
+each channel file.
+"""
+
+from .opencli import (  # noqa: F401
+    OPENCLI_EXTENSION_URL,
+    OPENCLI_PACKAGE,
+    OpenCLIStatus,
+    opencli_status,
+    opencli_summary,
+)
diff --git a/agent_reach/backends/opencli.py b/agent_reach/backends/opencli.py
new file mode 100644
index 0000000..816d33a
--- /dev/null
+++ b/agent_reach/backends/opencli.py
@@ -0,0 +1,94 @@
+# -*- coding: utf-8 -*-
+"""OpenCLI backend probing.
+
+OpenCLI (github.com/jackwener/opencli) drives the user's real Chrome via a
+browser-bridge extension + local daemon, reusing existing login sessions —
+zero per-platform configuration, desktop-only (no headless).
+
+Probing notes (verified live):
+  - `opencli doctor` AUTO-STARTS the daemon — a side effect, so health
+    checks must use `opencli daemon status` (pure query) instead.
+  - Exit codes are always 0; status must be parsed from text output.
+  - Extension connectivity is volatile (drops when Chrome restarts and
+    reconnects on demand) — report it, but treat "installed + daemon
+    reachable" as the stable signal.
+"""
+
+from dataclasses import dataclass
+
+from agent_reach.probe import probe_command
+
+OPENCLI_PACKAGE = "@jackwener/opencli"
+OPENCLI_EXTENSION_URL = (
+    "https://chromewebstore.google.com/detail/opencli/ildkmabpimmkaediidaifkhjpohdnifk"
+)
+
+
+@dataclass
+class OpenCLIStatus:
+    installed: bool = False
+    broken: bool = False
+    daemon_running: bool = False
+    extension_connected: bool = False
+    version: str = ""
+    hint: str = ""
+
+    @property
+    def ready(self) -> bool:
+        """Fully usable right now: extension connected to the daemon."""
+        return self.installed and not self.broken and self.extension_connected
+
+
+def opencli_status(timeout: int = 10) -> OpenCLIStatus:
+    """Probe OpenCLI install + daemon/extension state without side effects."""
+    version_probe = probe_command(
+        "opencli", ["--version"], timeout=timeout, package=OPENCLI_PACKAGE
+    )
+    if version_probe.status == "missing":
+        return OpenCLIStatus(installed=False)
+    if not version_probe.ok:
+        return OpenCLIStatus(
+            installed=True,
+            broken=True,
+            hint=(
+                "opencli 命令存在但无法执行（node 环境损坏），重装：\n"
+                f"  npm install -g {OPENCLI_PACKAGE}"
+            ),
+        )
+
+    st = OpenCLIStatus(installed=True, version=version_probe.output.strip())
+
+    daemon_probe = probe_command(
+        "opencli", ["daemon", "status"], timeout=timeout, package=OPENCLI_PACKAGE
+    )
+    output = daemon_probe.output if daemon_probe.ok else ""
+    # `opencli daemon status` prints lines like:
+    #   Daemon: running (PID 37389) / Daemon: not running
+    #   Extension: connected / Extension: disconnected
+    for line in output.splitlines():
+        line = line.strip().lower()
+        if line.startswith("daemon:"):
+            st.daemon_running = "not running" not in line and "running" in line
+        elif line.startswith("extension:"):
+            st.extension_connected = "disconnected" not in line and "connected" in line
+
+    if not st.extension_connected:
+        st.hint = (
+            "OpenCLI 已安装，但 Chrome 扩展未连接。\n"
+            f"  1. 安装扩展（需手动点一次）：{OPENCLI_EXTENSION_URL}\n"
+            "  2. 保持 Chrome 打开，运行 `opencli doctor` 验证"
+        )
+    return st
+
+
+def opencli_summary(st: OpenCLIStatus) -> str:
+    """One-line state description for channel messages / install output."""
+    if not st.installed:
+        return "OpenCLI 未安装"
+    if st.broken:
+        return "OpenCLI 无法执行（node 环境损坏）"
+    if st.ready:
+        return f"OpenCLI 可用（浏览器登录态，v{st.version}）"
+    if st.daemon_running:
+        return "OpenCLI 已安装，等待 Chrome 扩展连接"
+    return "OpenCLI 已安装（daemon 未运行，使用时自动启动；需 Chrome 扩展）"
diff --git a/agent_reach/cli.py b/agent_reach/cli.py
index ccda286..99db8b8 100644
--- a/agent_reach/cli.py
+++ b/agent_reach/cli.py
@@ -199,6 +199,7 @@ def _cmd_install(args):
         "xiaohongshu": _install_xhs_deps,
         "reddit":      _install_reddit_deps,
         "bilibili":    _install_bili_deps,
+        "opencli":     _install_opencli_deps,  # cross-channel backend, desktop only
         # xueqiu: cookie-only, no install step
         # linkedin: manual setup, no auto-install
     }
@@ -252,6 +253,10 @@ def _cmd_install(args):
     if requested_channels and not dry_run and not safe_mode:
         print()
         print("Installing optional channels...")
+        if env == "server" and "opencli" in requested_channels:
+            # OpenCLI rides a real desktop Chrome session — useless headless
+            requested_channels.discard("opencli")
+            print("  -- OpenCLI 需要桌面环境 + Chrome，服务器环境跳过")
         for ch_name in sorted(requested_channels):
             installer = CHANNEL_INSTALLERS.get(ch_name)
             if installer:
@@ -716,6 +721,55 @@ def _install_xhs_deps():
     print("  [!]  xhs-cli install failed. Run: pipx install xiaohongshu-cli")
 
 
+def _install_opencli_deps():
+    """Install OpenCLI — cross-platform backend riding the user's Chrome session.
+
+    Desktop-only. The npm package installs automatically; the Chrome
+    extension CANNOT be installed programmatically (Chrome security model),
+    so we print a one-click guide instead.
+    """
+    import shutil
+    import subprocess
+
+    from agent_reach.backends import (
+        OPENCLI_EXTENSION_URL,
+        OPENCLI_PACKAGE,
+        opencli_status,
+        opencli_summary,
+    )
+
+    print("Setting up OpenCLI (browser-session backend, desktop only)...")
+    st = opencli_status()
+    if st.installed and not st.broken:
+        print(f"  ✅ {opencli_summary(st)}")
+        if not st.ready:
+            print(f"  {st.hint}")
+        return
+
+    if not shutil.which("npm"):
+        print("  [!]  OpenCLI requires Node.js ≥ 20. Install Node first:")
+        print("       https://nodejs.org  （或 brew install node）")
+        return
+
+    try:
+        subprocess.run(
+            ["npm", "install", "-g", OPENCLI_PACKAGE],
+            capture_output=True, encoding="utf-8", errors="replace", timeout=300,
+        )
+    except Exception:
+        pass
+
+    st = opencli_status()
+    if st.installed and not st.broken:
+        print("  ✅ OpenCLI installed")
+        print("  最后一步（必须手动，Chrome 安全限制）：安装浏览器扩展")
+        print(f"    1. 打开 {OPENCLI_EXTENSION_URL}")
+        print("    2. 点「添加至 Chrome」")
+        print("    3. 运行 `opencli doctor` 验证连接")
+    else:
+        print(f"  [!]  OpenCLI install failed. Run: npm install -g {OPENCLI_PACKAGE}")
+
+
 def _install_reddit_deps():
     """Install rdt-cli for Reddit search + reading."""
     import shutil
diff --git a/tests/test_opencli_backend.py b/tests/test_opencli_backend.py
new file mode 100644
index 0000000..787129f
--- /dev/null
+++ b/tests/test_opencli_backend.py
@@ -0,0 +1,79 @@
+# -*- coding: utf-8 -*-
+"""Tests for the OpenCLI cross-channel backend probing."""
+
+from unittest.mock import patch
+
+from agent_reach.backends import opencli_status, opencli_summary
+from agent_reach.probe import ProbeResult
+
+
+def _status_with(version_probe, daemon_probe=None):
+    """Run opencli_status with probe_command patched per call."""
+    calls = []
+
+    def fake_probe(cmd, args=("--version",), **kwargs):
+        calls.append(list(args))
+        if list(args) == ["--version"]:
+            return version_probe
+        return daemon_probe or ProbeResult("missing")
+
+    with patch("agent_reach.backends.opencli.probe_command", side_effect=fake_probe):
+        return opencli_status(), calls
+
+
+def test_not_installed():
+    st, _ = _status_with(ProbeResult("missing"))
+    assert not st.installed
+    assert not st.ready
+    assert "未安装" in opencli_summary(st)
+
+
+def test_broken_node_env_gives_npm_hint():
+    st, _ = _status_with(ProbeResult("broken", hint="x"))
+    assert st.installed and st.broken
+    assert "npm install -g @jackwener/opencli" in st.hint
+    assert not st.ready
+
+
+def test_daemon_running_extension_connected_is_ready():
+    daemon_out = "Daemon: running (PID 37389)\nVersion: v1.8.3\nExtension: connected\n"
+    st, _ = _status_with(
+        ProbeResult("ok", output="1.8.3"),
+        ProbeResult("ok", output=daemon_out),
+    )
+    assert st.installed and st.daemon_running and st.extension_connected
+    assert st.ready
+    assert "1.8.3" in opencli_summary(st)
+
+
+def test_extension_disconnected_not_ready_with_store_guide():
+    daemon_out = "Daemon: running (PID 1)\nExtension: disconnected\n"
+    st, _ = _status_with(
+        ProbeResult("ok", output="1.8.3"),
+        ProbeResult("ok", output=daemon_out),
+    )
+    assert st.daemon_running and not st.extension_connected
+    assert not st.ready
+    assert "chromewebstore.google.com" in st.hint
+
+
+def test_daemon_not_running_parsed_correctly():
+    st, _ = _status_with(
+        ProbeResult("ok", output="1.8.3"),
+        ProbeResult("ok", output="Daemon: not running\n"),
+    )
+    assert st.installed
+    assert not st.daemon_running
+    assert not st.extension_connected
+    assert "自动启动" in opencli_summary(st)
+
+
+def test_probe_uses_daemon_status_not_doctor():
+    """`opencli doctor` auto-starts the daemon (side effect) — health checks
+    must only ever call `daemon status`."""
+    _, calls = _status_with(
+        ProbeResult("ok", output="1.8.3"),
+        ProbeResult("ok", output="Daemon: not running\n"),
+    )
+    assert ["daemon", "status"] in calls
+    assert ["doctor"] not in calls