browser_fill

Fill input field with value

SERVERClaude Mobile SOURCEalexgladkov/claude-in-mobile

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/alexgladkov-claude-in-mobile/browser-fill.md

WHAT IT DOES

What browser_fill does on Claude Mobile

AI agents use browser_fill to create or update resources in Claude Mobile, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Claude Mobile environment.

RISK

Why browser_fill is rated Medium

The tool performs a write operation by populating input fields with values. While this is reversible (the user could clear or change the field), it modifies application state on the device. Given the mobile device automation context and that input field manipulation could affect app behavior, authentication, or data entry workflows, this warrants 'medium' severity.

From the tool's definition Tool name 'browser_fill' and description 'Fill input field with value' indicates it modifies data in input fields on a mobile device via automation. This creates or modifies form data reversibly.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs browser_fill safely

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

browser_fill Rate-limited

browser_fill stays usable, but capped: an agent stuck in a loop can't make hundreds of changes 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_fill": {
      "limits": [
        {
          "counter": "browser_fill_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Claude Mobile, apply this rule, and every browser_fill call is checked against it from then on.

FAQ

Questions about browser_fill

What does the browser_fill tool do? +

Fill input field with value. It is categorised as a Write tool in the Claude Mobile MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on browser_fill? +

Register the Claude Mobile MCP server in PolicyLayer and add a rule for browser_fill: 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 Claude Mobile. Nothing to install.

What risk level is browser_fill? +

browser_fill is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit browser_fill? +

Yes. Add a rate_limit block to the browser_fill 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_fill completely? +

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

browser_fill is provided by the Claude Mobile MCP server (alexgladkov/claude-in-mobile). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Claude Mobile, and thousands of servers like it.

This server

All 198 Claude Mobile tools →

Across the catalogue

The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →