Medium Risk

create_file

Create a new file (alias for write_file). Creates or overwrites a file. Only works within allowed directories.

How to control create_file ↓

What create_file does on Claude TypeScript MCP Servers

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

Medium Risk

Why create_file needs a policy

This tool creates or modifies files reversibly within constrained directories. It is not irreversible (files can be deleted), not destructive in the sense of DROP/DELETE operations, and not code execution. The 'overwrites' capability elevates it from pure Read to Write, but the directory restriction limits blast radius to medium severity. Confidence is high because the description is clear and unambiguous.

From the tool's definition Creates or overwrites a file. Only works within allowed directories.

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

How to control create_file

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

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_file": {
      "limits": [
        {
          "counter": "create_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

create_file 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.

  1. Create a free account and register Claude TypeScript MCP Servers — 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.
LIMIT THIS TOOL →

Free to start. No card required.

Related tools and policies

Go deeper

Questions about create_file

What does the create_file tool do? +

Create a new file (alias for write_file). Creates or overwrites a file. Only works within allowed directories. It is categorised as a Write tool in the Claude TypeScript MCP Servers MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_file? +

Register the Claude TypeScript MCP Servers MCP server in PolicyLayer and add a rule for create_file: 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 TypeScript MCP Servers. Nothing to install.

What risk level is create_file? +

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

Can I rate-limit create_file? +

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

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

create_file is provided by the Claude TypeScript MCP Servers MCP server (ukkz/claude-ts-mcps). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Claude TypeScript MCP Servers tool call.

Start from Claude TypeScript MCP Servers, 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.

84 Claude TypeScript MCP Servers tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.