High Risk →

inject_hook

Inject an existing hook into the current page.

How to control inject_hook ↓

What inject_hook does on JS Reverse Strong MCP

AI agents invoke inject_hook to trigger actions in JS Reverse Strong MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

High Risk

Why inject_hook needs a policy

Hook injection runs code inside a running browser page, altering runtime behavior. This is an Execute-category action because it triggers external operations (code execution in the browser context) whose effects depend on the hook being injected. It carries high severity since a misused hook could steal credentials, exfiltrate data, or tamper with page logic.

From the tool's definition "Inject an existing hook into the current page" — injecting hooks into a live browser page executes arbitrary JavaScript in the page context

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

How to control inject_hook

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

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "inject_hook": {
      "limits": [
        {
          "counter": "inject_hook_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

inject_hook 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.

  1. Create a free account and register JS Reverse Strong MCP — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
RATE-LIMIT THIS TOOL →

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Related tools and policies

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Questions about inject_hook

What does the inject_hook tool do? +

Inject an existing hook into the current page. It is categorised as a Execute tool in the JS Reverse Strong MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on inject_hook? +

Register the JS Reverse Strong MCP server in PolicyLayer and add a rule for inject_hook: 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 JS Reverse Strong MCP. Nothing to install.

What risk level is inject_hook? +

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

Can I rate-limit inject_hook? +

Yes. Add a rate_limit block to the inject_hook 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 inject_hook completely? +

Set action: deny in the PolicyLayer policy for inject_hook. 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 inject_hook? +

inject_hook is provided by the JS Reverse Strong MCP server (lwjjike/jsreverser-strong-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every JS Reverse Strong MCP tool call.

Start from JS Reverse Strong MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

85 JS Reverse Strong MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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