open_web_player

THE RISK

High Risk

Why open_web_player needs a policy

This tool starts a local web server and generates/serves a web UI, which constitutes executing an external operation (spinning up a server process and binding to a port). It's not merely reading data, but actively triggering a side-effecting operation that affects the local system environment.

From the tool's definition Generate and serve a local web player UI... Returns a localhost URL

Documented attack patterns abuse exactly the kind of access open_web_player gives an agent:

POLICY

How to control open_web_player

PolicyLayer is an MCP gateway — it sits between your AI agents and Netease Music, and nothing reaches the server without passing your rules. This is the rule we recommend for open_web_player:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "open_web_player": {
      "limits": [
        {
          "counter": "open_web_player_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

open_web_player stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

Create a free account and register Netease Music — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Netease Music tools

Destructive shutdown Use this when the user asks to end the listening session, stop listening to music, close t Execute play_track Play a NetEase numeric song ID with neteasecli/mpv and return song info plus the start lis Execute stop Stop current neteasecli/mpv playback and clear listening state. Execute next_song Switch to another requested song by searching and playing it. Use this for natural-languag Execute pause Pause current neteasecli/mpv playback. Execute play_song Search for a song, play the best match with neteasecli/mpv, and return song info plus list Execute resume Resume paused neteasecli/mpv playback. Write setup_netease_login Use this when the user needs to set up, log in, or troubleshoot neteasecli. It checks inst

All 13 Netease Music tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Netease Music → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about open_web_player

What does the open_web_player tool do? +

Generate and serve a local web player UI for search/play/pause/stop and lyric context. Returns a localhost URL. It is categorised as a Execute tool in the Netease Music MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on open_web_player? +

Register the Netease Music MCP server in PolicyLayer and add a rule for open_web_player: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Netease Music. Nothing to install.

What risk level is open_web_player? +

open_web_player is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit open_web_player? +

Yes. Add a rate_limit block to the open_web_player rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block open_web_player completely? +

Set action: deny in the PolicyLayer policy for open_web_player. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides open_web_player? +

open_web_player is provided by the Netease Music MCP server (luuu-h/netease-music-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Netease Music tool call.

Start from Netease Music, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →