file_write

Store a file for an app (create or overwrite by path).

SERVEROpen Mcp Apps SOURCE@2nd1st/open-mcp-apps

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/2nd1st-open-mcp-apps/file-write.md

WHAT IT DOES

What file_write does on Open Mcp Apps

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

RISK

Why file_write is rated Medium

The tool creates or overwrites files, which is a reversible write operation. While 'overwrite' could suggest destructive potential, the primary function is file storage/creation within an app context, making it Write rather than Destructive. However, severity is high because overwriting files can cause data loss if misused by an agent without proper validation of paths or file contents.

From the tool's definition Tool name 'file_write' with description 'Store a file for an app (create or overwrite by path)' indicates file creation or modification operations.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs file_write safely

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

file_write Rate-limited

file_write 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": {
    "file_write": {
      "limits": [
        {
          "counter": "file_write_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 Open Mcp Apps, apply this rule, and every file_write call is checked against it from then on.

FAQ

Questions about file_write

What does the file_write tool do? +

Store a file for an app (create or overwrite by path). It is categorised as a Write tool in the Open Mcp Apps MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on file_write? +

Register the Open Mcp Apps MCP server in PolicyLayer and add a rule for file_write: 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 Open Mcp Apps. Nothing to install.

What risk level is file_write? +

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

Can I rate-limit file_write? +

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

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

file_write is provided by the Open Mcp Apps MCP server (@2nd1st/open-mcp-apps). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Open Mcp Apps, and thousands of servers like it.

This server

All 32 Open Mcp Apps tools →

Across the catalogue

write_file on 0sec → The MCP Attack Database →

Guides

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