# esbuild

Runs the esbuild bundler and returns structured errors, warnings, and output files.

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

## Facts

- Tool: `esbuild`
- Server: Npm (`Dave-London/Pare`) — https://policylayer.com/tools/io-github-dave-london-npm.md
- Homepage: https://github.com/Dave-London/pare
- Risk category: Execute (High 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": "esbuild",
    "arguments": {}
  }
}
```

## Why esbuild is rated High

This tool executes an external build process (esbuild). It reads source files, runs transformations, and writes output files. The effects are argument-dependent (entry points, output dirs, plugins, etc.), placing it firmly in Execute. Severity is medium because misuse could write arbitrary files or execute build plugins, but it does not directly delete data or move money.

From the tool's own definition: "'Runs the esbuild bundler' — actively executes the esbuild build tool, triggering file system reads/writes and code compilation whose effects depend on arguments"

## Use case

AI agents invoke esbuild to trigger actions in Npm. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "esbuild": {
      "limits": [
        {
          "counter": "esbuild_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Npm (201)

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