# DevUtils MCP Server
**36 everyday developer tools for any MCP-compatible AI assistant.** Hashing, encoding, UUID generation, JWT decoding, JSON formatting, network tools, text utilities, and more — all local, no external APIs.
Think of it as **`busybox` for developer tools** — small, essential, and always useful.
**Also available as a plugin:** [devutils-cursor-plugin](https://github.com/paladini/devutils-cursor-plugin) — one-click install for Cursor and Claude Code.
---
## Why?
Every developer needs to hash strings, encode/decode data, generate UUIDs, decode JWTs, format JSON, calculate CIDR ranges, and convert timestamps **every day**. DevUtils MCP Server brings all of these tools directly into your AI assistant — works with Claude, Cursor, VS Code, Windsurf, and any other MCP-compatible client.
---
## Installation
> **Prerequisite:** [Node.js](https://nodejs.org/) 18+ (Node 22 recommended). Verify with `node -v`.
### One-click / plugin
Use the **Add to Cursor** / **VS Code** badges above, or install the plugin:
```text
/plugin marketplace add paladini/devutils-cursor-plugin
/plugin install devutils-mcp@devutils-cursor-plugin
```
Cursor: **Settings → Customize**, or add from GitHub `paladini/devutils-cursor-plugin`.
### npx (no install)
```bash
npx -y devutils-mcp-server
```
### npm
```bash
npm install -g devutils-mcp-server
devutils-mcp-server
```
### Docker
```bash
# Published image (when available)
docker run -i --rm ghcr.io/paladini/devutils-mcp-server
# Or build locally
docker build -t devutils-mcp-server .
docker run -i --rm devutils-mcp-server
# Or with Compose
docker compose build
docker compose run --rm -i devutils-mcp
```
### Official MCP Registry
Listed as [`io.github.paladini/devutils-mcp-server`](https://registry.modelcontextprotocol.io). Search for `io.github.paladini/devutils`.
### GitHub Packages
Releases are dual-published to npm and GitHub Packages as [`@paladini/devutils-mcp-server`](https://github.com/paladini/devutils-mcp-server/pkgs/npm/devutils-mcp-server) (see [`.github/workflows/release.yml`](.github/workflows/release.yml)). Prefer the public npm package for most installs; use GitHub Packages when you already authenticate against `npm.pkg.github.com`.
```bash
# After authenticating to npm.pkg.github.com for the @paladini scope:
npx -y @paladini/devutils-mcp-server
```
### Smithery
Also available on [Smithery](https://smithery.ai/server/devutils-mcp-server).
---
## Client setup
### Cursor
**One-click:** use the **Add to Cursor** badge at the top of this README.
**Plugin (recommended):** Install [DevUtils MCP](https://github.com/paladini/devutils-cursor-plugin) from **Cursor Settings → Customize**.
**Manual:** Add to `~/.cursor/mcp.json`:
```json
{
"mcpServers": {
"devutils": {
"command": "npx",
"args": ["-y", "devutils-mcp-server"]
}
}
}
```
### Claude Desktop
Add to `~/Library/Application Support/Claude/claude_desktop_config.json` (macOS) or `%APPDATA%\Claude\claude_desktop_config.json` (Windows):
```json
{
"mcpServers": {
"devutils": {
"command": "npx",
"args": ["-y", "devutils-mcp-server"]
}
}
}
```
Or with Docker:
```json
{
"mcpServers": {
"devutils": {
"command": "docker",
"args": ["run", "-i", "--rm", "ghcr.io/paladini/devutils-mcp-server"]
}
}
}
```
### Claude Code
```text
/plugin marketplace add paladini/devutils-cursor-plugin
/plugin install devutils-mcp@devutils-cursor-plugin
```
### VS Code (GitHub Copilot)
**One-click:** use the VS Code badge at the top, or add to `.vscode/mcp.json` / user settings:
```json
{
"servers": {
"devutils": {
"type": "stdio",
"command": "npx",
"args": ["-y", "devutils-mcp-server"]
}
}
}
```
### Windsurf
Add to `~/.codeium/windsurf/mcp_config.json`:
```json
{
"mcpServers": {
"devutils": {
"command": "npx",
"args": ["-y", "devutils-mcp-server"]
}
}
}
```
### Docker MCP Toolkit (Docker Desktop)
If this server is available in the [Docker MCP Catalog](https://hub.docker.com/mcp):
1. Open **Docker Desktop → MCP Toolkit**
2. Search for **DevUtils**
3. Click **Enable**
### Local development
```bash
npm install
npm run dev
```
---
## Available tools (36)
### Hash (6)
| Tool | Description |
|------|-------------|
| `hash_md5` | Generate MD5 hash |
| `hash_sha1` | Generate SHA-1 hash |
| `hash_sha256` | Generate SHA-256 hash |
| `hash_sha512` | Generate SHA-512 hash |
| `hash_bcrypt` | Generate bcrypt hash (configurable rounds) |
| `hash_bcrypt_verify` | Verify string against bcrypt hash |
### Encoding (8)
| Tool | Description |
|------|-------------|
| `base64_encode` | Encode string to Base64 |
| `base64_decode` | Decode Base64 to string |
| `url_encode` | URL-encode (percent-encoding) |
| `url_decode` | Decode URL-encoded string |
| `html_encode` | Encode HTML entities |
| `html_decode` | Decode HTML entities |
| `hex_encode` | Encode string to hex |
| `hex_decode` | Decode hex to string |
### Generators (4)
| Tool | Description |
|------|-------------|
| `generate_uuid` | Cryptographic UUID v4 (batch support) |
| `generate_nanoid` | Compact URL-friendly ID (configurable length) |
| `generate_password` | Secure password (configurable complexity) |
| `generate_random_hex` | Random hex string (configurable length) |
### JWT (2)
| Tool | Description |
|------|-------------|
| `jwt_decode` | Decode JWT header & payload (with human-readable dates) |
| `jwt_validate` | Validate JWT structure & expiration |
### Formatters (3)
| Tool | Description |
|------|-------------|
| `json_format` | Pretty-print or minify JSON |
| `json_validate` | Validate JSON with error location |
| `json_path_query` | Extract values using dot-notation path |
### Converters (5)
| Tool | Description |
|------|-------------|
| `timestamp_to_date` | Unix timestamp → human date (timezone support) |
| `date_to_timestamp` | Date string → Unix timestamp |
| `number_base_convert` | Convert between bases (bin/oct/dec/hex/any) |
| `color_convert` | Convert colors (HEX ↔ RGB ↔ HSL) |
| `byte_convert` | Convert byte units (B/KB/MB/GB/TB/PB) |
### Network (2)
| Tool | Description |
|------|-------------|
| `cidr_calculate` | CIDR → network, broadcast, mask, host range, host count |
| `ip_validate` | Validate & classify IPv4/IPv6 address |
### Text (6)
| Tool | Description |
|------|-------------|
| `text_stats` | Character/word/line/sentence count, reading time |
| `lorem_ipsum` | Generate placeholder text |
| `case_convert` | Convert between camelCase, snake_case, PascalCase, etc. |
| `slugify` | Convert string to URL-friendly slug |
| `regex_test` | Test regex pattern against input |
| `text_diff` | Line-by-line diff between two texts |
---
## Architecture
```
src/
├── index.ts # MCP server entry point (stdio transport)
└── tools/
├── hash.ts # Cryptographic hash functions
├── encoding.ts # Encode/decode utilities
├── generators.ts # ID and password generators
├── jwt.ts # JWT decode and validation
├── formatters.ts # JSON formatting and querying
├── converters.ts # Data type and unit converters
├── network.ts # Network calculation utilities
└── text.ts # Text analysis and manipulation
```
**Tech stack:** TypeScript + Node.js 22 · [`@modelcontextprotocol/sdk`](https://github.com/modelcontextprotocol/typescript-sdk) · `bcryptjs` · `nanoid` · `zod`
**Zero external API dependencies.** All tools run locally with no network calls.
---
## Docker
The image uses a multi-stage build for minimal size:
1. **Build stage:** Compiles TypeScript on Node 22 Alpine
2. **Runtime stage:** Runs compiled JS on Node 22 Alpine as a non-root user
```bash
docker build -t devutils-mcp-server .
# Smoke-test with an MCP initialize request
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"1.0.0"}}}' | docker run -i --rm devutils-mcp-server
```
---
## FAQ & design philosophy
### Why MCP, and not just a library?
**Valid criticism:** If you're writing Python scripts and need to hash something, `hashlib` is 2 lines of code. Why run MCP overhead?
**Answer:** This server is optimized for **AI agents** in multi-step workflows, not programmers writing code:
1. **AI hallucination cost >> MCP overhead** — An AI model spending 50ms calling an MCP tool (vs. 1ms library call) is negligible when the alternative is the model *making up a hash* or using the wrong encoding.
2. **Reliable tool semantics** — MCP enforces strict tool contracts. For example, `jwt_decode` *always* returns human-readable dates with timezone support.
3. **Universally accessible** — Any MCP-compatible client can use these tools. A Python library only works if your agent is Python-based.
4. **Multi-tenant safety** — MCP provides explicit tool whitelisting with input validation.
### When to use DevUtils versus alternatives
**Use DevUtils if:**
- You're using Claude, Cursor, VS Code Copilot, Windsurf, or any MCP-compatible AI assistant
- You want reliable, validated utility operations in AI workflows
- You need 36 tools in one package
**Don't use DevUtils if:**
- You're writing regular application code (use native libraries)
- You need extreme performance (direct library calls are faster)
- Your AI client does not support MCP
### Design philosophy
- **Small & focused:** 36 utilities, zero external APIs, ~50MB container
- **Security-first:** Non-root user, Alpine Linux, minimal attack surface
- **AI-friendly:** Consistent naming (`_`), strict schemas, human-readable outputs
- **Client-agnostic:** Works with any MCP-compatible client via stdio transport
---
## Available on
| Channel | Link |
| --- | --- |
| **Official MCP Registry** | `io.github.paladini/devutils-mcp-server` — [registry.modelcontextprotocol.io](https://registry.modelcontextprotocol.io) |
| **npm** | [devutils-mcp-server](https://www.npmjs.com/package/devutils-mcp-server) |
| **GitHub Packages** | [`@paladini/devutils-mcp-server`](https://github.com/paladini/devutils-mcp-server/pkgs/npm/devutils-mcp-server) (dual-publish on release tags) |
| **GHCR (Docker)** | `ghcr.io/paladini/devutils-mcp-server` |
| **Glama** | [glama.ai/mcp/servers/paladini/devutils-mcp-server](https://glama.ai/mcp/servers/paladini/devutils-mcp-server) |
| **Smithery** | [smithery.ai/server/devutils-mcp-server](https://smithery.ai/server/devutils-mcp-server) |
| **Cursor / Claude plugin** | [devutils-cursor-plugin](https://github.com/paladini/devutils-cursor-plugin) |
---
## Contributing
Questions and ideas: [GitHub Discussions](https://github.com/paladini/devutils-mcp-server/discussions)
Security reports: see [SECURITY.md](SECURITY.md).
1. Fork the repository
2. Create your feature branch (`git checkout -b feat/amazing-tool`)
3. Commit your changes (`git commit -m 'feat: add amazing tool'`)
4. Push to the branch (`git push origin feat/amazing-tool`)
5. Open a Pull Request
See [CHANGELOG.md](CHANGELOG.md).
---
## License
MIT © [Fernando Paladini](https://github.com/paladini)