# file_write_begin

Start a chunked upload for a file too big for file_write

Agent View of the PolicyLayer registry record for `file_write_begin`. HTML page: https://policylayer.com/tools/2nd1st-open-mcp-apps/file-write-begin

## Facts

- Tool: `file_write_begin`
- Server: Open Mcp Apps (`@2nd1st/open-mcp-apps`) — https://policylayer.com/tools/2nd1st-open-mcp-apps.md
- Install: `npx -y @2nd1st/open-mcp-apps`
- Homepage: https://github.com/2nd1st/open-mcp-apps
- 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": "file_write_begin",
    "arguments": {}
  }
}
```

## Why file_write_begin is rated Medium

This tool creates or modifies files by initiating an upload process. While not destructive (reversible), it is a Write operation with high severity due to potential for an AI agent to write large files to persistent storage, possibly consuming resources or overwriting existing data.

From the tool's own definition: "Tool name is 'file_write_begin' and description states 'Start a chunked upload for a file' — directly indicates file creation/modification capability. The 'chunked upload' pattern is a standard Write operation for handling large files."

## Use case

AI agents use file_write_begin 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.

## Recommended policy (PolicyLayer)

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

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

## Other tools on Open Mcp Apps (31)

- `data_delete_item` — Destructive — https://policylayer.com/tools/2nd1st-open-mcp-apps/data-delete-item.md
- `delete_app` — Destructive — https://policylayer.com/tools/2nd1st-open-mcp-apps/delete-app.md
- `file_delete` — Destructive — https://policylayer.com/tools/2nd1st-open-mcp-apps/file-delete.md
- `call_function` — Execute — https://policylayer.com/tools/2nd1st-open-mcp-apps/call-function.md
- `app_store_list` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/app-store-list.md
- `data_changes` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/data-changes.md
- `data_list` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/data-list.md
- `file_list` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/file-list.md
- `file_read` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/file-read.md
- `get_app` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/get-app.md
- `get_app_guide` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/get-app-guide.md
- `get_app_html` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/get-app-html.md
- `get_data_version` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/get-data-version.md
- `get_ui_preference_schema` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/get-ui-preference-schema.md
- `list_app_checkpoints` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/list-app-checkpoints.md
- `list_apps` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/list-apps.md
- `list_data_collections` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/list-data-collections.md
- `preview_app_store_entry` — Read — https://policylayer.com/tools/2nd1st-open-mcp-apps/preview-app-store-entry.md
- `apply_data_writes` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/apply-data-writes.md
- `data_add_item` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/data-add-item.md
- `data_move_item` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/data-move-item.md
- `data_update_item` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/data-update-item.md
- `edit_app` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/edit-app.md
- `file_write` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/file-write.md
- `file_write_chunk` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/file-write-chunk.md
- `file_write_commit` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/file-write-commit.md
- `install_from_app_store` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/install-from-app-store.md
- `promote_app` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/promote-app.md
- `restore_app` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/restore-app.md
- `save_app` — Write — https://policylayer.com/tools/2nd1st-open-mcp-apps/save-app.md
- …and 1 more: https://policylayer.com/tools/2nd1st-open-mcp-apps.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`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=2nd1st-open-mcp-apps · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/2nd1st-open-mcp-apps