docs: require explicit channel login command

README.md

@@ -172,7 +172,7 @@ nanobot --version
 
 ```bash
 rm -rf ~/.nanobot/bridge
-nanobot channels login
+nanobot channels login whatsapp
 ```
 
 ## 🚀 Quick Start
@@ -462,7 +462,7 @@ Requires **Node.js ≥18**.
 **1. Link device**
 
 ```bash
-nanobot channels login
+nanobot channels login whatsapp
 # Scan QR with WhatsApp → Settings → Linked Devices
 ```
 
@@ -483,7 +483,7 @@ nanobot channels login
 
 ```bash
 # Terminal 1
-nanobot channels login
+nanobot channels login whatsapp
 
 # Terminal 2
 nanobot gateway
@@ -491,7 +491,7 @@ nanobot gateway
 
 > WhatsApp bridge updates are not applied automatically for existing installations.
 > After upgrading nanobot, rebuild the local bridge with:
-> `rm -rf ~/.nanobot/bridge && nanobot channels login`
+> `rm -rf ~/.nanobot/bridge && nanobot channels login whatsapp`
 
 </details>
 
@@ -1467,7 +1467,7 @@ nanobot gateway --config ~/.nanobot-telegram/config.json --workspace /tmp/nanobo
 | `nanobot gateway` | Start the gateway |
 | `nanobot status` | Show status |
 | `nanobot provider login openai-codex` | OAuth login for providers |
-| `nanobot channels login` | Link WhatsApp (scan QR) |
+| `nanobot channels login <channel>` | Authenticate a channel interactively |
 | `nanobot channels status` | Show channel status |
 
 Interactive mode exits: `exit`, `quit`, `/exit`, `/quit`, `:q`, or `Ctrl+D`.

tests/test_commands.py

@@ -616,3 +616,9 @@ def test_gateway_cli_port_overrides_configured_port(monkeypatch, tmp_path: Path)
 
     assert isinstance(result.exception, _StopGatewayError)
     assert "port 18792" in result.stdout
+
+
+def test_channels_login_requires_channel_name() -> None:
+    result = runner.invoke(app, ["channels", "login"])
+
+    assert result.exit_code == 2