browser_block

Block URLs matching patterns (substring match on fetch/XHR).

SERVERTermux Browser Pilot SOURCEsalviz/termux-browser-pilot

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/salviz-termux-browser-pilot/browser-block.md

WHAT IT DOES

What browser_block does on Termux Browser Pilot

AI agents invoke browser_block to trigger actions in Termux Browser Pilot. 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.

RISK

Why browser_block is rated High

This tool modifies the browser's network behavior by intercepting and blocking fetch/XHR requests matching specified URL patterns. It triggers an active runtime operation that affects how the browser processes network requests — not a simple data read or write, but an execution of a filtering/interception rule that alters external operations.

From the tool's definition Block URLs matching patterns (substring match on fetch/XHR)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs browser_block safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Termux Browser Pilot, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For browser_block, this is the rule to start with:

browser_block Rate-limited

browser_block 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.

View as policy code

policy.json

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

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Termux Browser Pilot, apply this rule, and every browser_block call is checked against it from then on.

FAQ

Questions about browser_block

What does the browser_block tool do? +

Block URLs matching patterns (substring match on fetch/XHR). It is categorised as a Execute tool in the Termux Browser Pilot MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on browser_block? +

Register the Termux Browser Pilot MCP server in PolicyLayer and add a rule for browser_block: 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 Termux Browser Pilot. Nothing to install.

What risk level is browser_block? +

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

Can I rate-limit browser_block? +

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

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

browser_block is provided by the Termux Browser Pilot MCP server (salviz/termux-browser-pilot). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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