# write_file

Write a file to the virtual filesystem (worker mock)

Agent View of the PolicyLayer registry record for `write_file`. HTML page: https://policylayer.com/tools/ruflo/write-file

## Facts

- Tool: `write_file`
- Server: Ruflo (`ruvnet/ruflo`) — https://policylayer.com/tools/ruflo.md
- Homepage: https://github.com/ruvnet/ruflo
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "write_file",
    "arguments": {}
  }
}
```

## Why write_file is rated Medium

This tool creates or modifies files in a virtual filesystem. It is reversible (files can be overwritten or deleted separately), so it falls under Write rather than Destructive. The severity is medium because malicious file writes could corrupt application state, inject code, or compromise system integrity, but the impact is limited to the virtual filesystem mock environment rather than production systems.

From the tool's own definition: "Tool name 'write_file' and description 'Write a file to the virtual filesystem (worker mock)' directly indicate file creation/modification capability."

## Use case

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

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Ruflo:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "write_file": {
      "limits": [
        {
          "counter": "write_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Ruflo (495)

- `agent_terminate` — Destructive — https://policylayer.com/tools/ruflo/agent-terminate.md
- `agentdb_batch` — Destructive — https://policylayer.com/tools/ruflo/agentdb-batch.md
- `agentdb_causal-edge-delete` — Destructive — https://policylayer.com/tools/ruflo/agentdb-causal-edge-delete.md
- `agentdb_causal-node-delete` — Destructive — https://policylayer.com/tools/ruflo/agentdb-causal-node-delete.md
- `agentdb_hierarchical-delete` — Destructive — https://policylayer.com/tools/ruflo/agentdb-hierarchical-delete.md
- `autopilot_reset` — Destructive — https://policylayer.com/tools/ruflo/autopilot-reset.md
- `config_reset` — Destructive — https://policylayer.com/tools/ruflo/config-reset.md
- `federation_wg_keyrotate` — Destructive — https://policylayer.com/tools/ruflo/federation-wg-keyrotate.md
- `hooks_intelligence-reset` — Destructive — https://policylayer.com/tools/ruflo/hooks-intelligence-reset.md
- `hooks_worker-cancel` — Destructive — https://policylayer.com/tools/ruflo/hooks-worker-cancel.md
- `iot_device_remove` — Destructive — https://policylayer.com/tools/ruflo/iot-device-remove.md
- `iot_device_unpair` — Destructive — https://policylayer.com/tools/ruflo/iot-device-unpair.md
- `iot_firmware_rollout_rollback` — Destructive — https://policylayer.com/tools/ruflo/iot-firmware-rollout-rollback.md
- `iot_fleet_delete` — Destructive — https://policylayer.com/tools/ruflo/iot-fleet-delete.md
- `iot_fleet_remove_device` — Destructive — https://policylayer.com/tools/ruflo/iot-fleet-remove-device.md
- `managed_agent_terminate` — Destructive — https://policylayer.com/tools/ruflo/managed-agent-terminate.md
- `memory_delete` — Destructive — https://policylayer.com/tools/ruflo/memory-delete.md
- `policy_revoke` — Destructive — https://policylayer.com/tools/ruflo/policy-revoke.md
- `ruvector_delete` — Destructive — https://policylayer.com/tools/ruflo/ruvector-delete.md
- `session_delete` — Destructive — https://policylayer.com/tools/ruflo/session-delete.md
- `system_reset` — Destructive — https://policylayer.com/tools/ruflo/system-reset.md
- `task_cancel` — Destructive — https://policylayer.com/tools/ruflo/task-cancel.md
- `wasm_agent_reset` — Destructive — https://policylayer.com/tools/ruflo/wasm-agent-reset.md
- `wasm_gallery_remove_custom` — Destructive — https://policylayer.com/tools/ruflo/wasm-gallery-remove-custom.md
- `workflow_cancel` — Destructive — https://policylayer.com/tools/ruflo/workflow-cancel.md
- `workflow_delete` — Destructive — https://policylayer.com/tools/ruflo/workflow-delete.md
- `agent_pool` — Execute — https://policylayer.com/tools/ruflo/agent-pool.md
- `agent_spawn` — Execute — https://policylayer.com/tools/ruflo/agent-spawn.md
- `agentdb_consolidate` — Execute — https://policylayer.com/tools/ruflo/agentdb-consolidate.md
- `agentdb_route` — Execute — https://policylayer.com/tools/ruflo/agentdb-route.md
- …and 465 more: https://policylayer.com/tools/ruflo.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=ruflo · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/ruflo