# biome-format

Formats files with Biome (format --write) and returns a structured list of changed files.

Agent View of the PolicyLayer registry record for `biome-format`. HTML page: https://policylayer.com/tools/io-github-dave-london-http/biome-format

## Facts

- Tool: `biome-format`
- Server: Http (`@paretools/http`) — https://policylayer.com/tools/io-github-dave-london-http.md
- Install: `npx -y @paretools/http`
- Homepage: https://github.com/Dave-London/Pare
- 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": "biome-format",
    "arguments": {}
  }
}
```

## Why biome-format is rated Medium

The tool creates or modifies data reversibly by formatting files on disk. While formatting is generally safe and reversible (the original unformatted code can be recovered from version control), the tool does write changes to files, which constitutes a Write operation.

From the tool's own definition: "Tool description states 'format --write' which modifies files. The 'Biome' formatter is used to format code files, and '--write' flag indicates changes are written back to disk, modifying the original files."

## Use case

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

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "biome-format": {
      "limits": [
        {
          "counter": "biome-format_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Http (201)

- `branch` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/branch.md
- `clean` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/clean.md
- `compose-down` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/compose-down.md
- `remove` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/remove.md
- `reset` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/reset.md
- `secret-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/secret-delete.md
- `tag` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/tag.md
- `variable-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/variable-delete.md
- `workspace` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/workspace.md
- `worktree` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/worktree.md
- `add` — Execute — https://policylayer.com/tools/io-github-dave-london-http/add.md
- `add-package` — Execute — https://policylayer.com/tools/io-github-dave-london-http/add-package.md
- `ansible-galaxy` — Execute — https://policylayer.com/tools/io-github-dave-london-http/ansible-galaxy.md
- `ansible-playbook` — Execute — https://policylayer.com/tools/io-github-dave-london-http/ansible-playbook.md
- `api` — Execute — https://policylayer.com/tools/io-github-dave-london-http/api.md
- `apply` — Execute — https://policylayer.com/tools/io-github-dave-london-http/apply.md
- `audit` — Execute — https://policylayer.com/tools/io-github-dave-london-http/audit.md
- `bazel` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bazel.md
- `biome-check` — Execute — https://policylayer.com/tools/io-github-dave-london-http/biome-check.md
- `bisect` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bisect.md
- `black` — Execute — https://policylayer.com/tools/io-github-dave-london-http/black.md
- `build` — Execute — https://policylayer.com/tools/io-github-dave-london-http/build.md
- `bundle-exec` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bundle-exec.md
- `bundle-install` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bundle-install.md
- `check` — Execute — https://policylayer.com/tools/io-github-dave-london-http/check.md
- `cherry-pick` — Execute — https://policylayer.com/tools/io-github-dave-london-http/cherry-pick.md
- `clippy` — Execute — https://policylayer.com/tools/io-github-dave-london-http/clippy.md
- `cmake` — Execute — https://policylayer.com/tools/io-github-dave-london-http/cmake.md
- `compose-build` — Execute — https://policylayer.com/tools/io-github-dave-london-http/compose-build.md
- `compose-up` — Execute — https://policylayer.com/tools/io-github-dave-london-http/compose-up.md
- …and 171 more: https://policylayer.com/tools/io-github-dave-london-http.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=io-github-dave-london-http · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-dave-london-http