# keccak-mcp

An MCP (Model Context Protocol) server that provides Keccak cryptographic hash tools.

## Tools

### `keccak_hash`

Compute a Keccak hash of the given input.

**Parameters:**

| Parameter  | Type     | Default       | Description                                                              |
| ---------- | -------- | ------------- | ------------------------------------------------------------------------ |
| `input`    | `string` | —             | The input string or hex-encoded bytes to hash                            |
| `variant`  | `enum`   | `keccak-256`  | Keccak variant: `keccak-224`, `keccak-256`, `keccak-384`, `keccak-512`  |
| `encoding` | `enum`   | `utf8`        | Input encoding: `utf8` (UTF-8 string) or `hex` (hex-encoded bytes)      |

**Response:**

```json
{
  "variant": "keccak-256",
  "encoding": "utf8",
  "input": "hello",
  "hash": "0x1c8aff950685c2ed4bc3174f3472287b56d9517b9c948127319a09a7a36deac8"
}
```

> **Note:** `keccak-256` is the variant used by Ethereum (distinct from SHA3-256).

## Installation

```bash
npm install
npm run build
```

## Usage

### Run directly

```bash
npm start
```

### Use as a CLI binary

```bash
node dist/index.js
```

## MCP Client Configuration

Add the server to your MCP client configuration. The server communicates over **stdio**.

### Claude Desktop (`claude_desktop_config.json`)

```json
{
  "mcpServers": {
    "keccak-mcp": {
      "command": "node",
      "args": ["${workspaceFolder}/dist/index.js"]
    }
  }
}
```

### VS Code (`.vscode/mcp.json`)

```json
{
  "servers": {
    "keccak-mcp": {
      "type": "stdio",
      "command": "node",
      "args": ["${workspaceFolder}/dist/index.js"]
    }
  }
}
```

## Development

```bash
# Build TypeScript
npm run build

# Build and run
npm run dev
```

## Dependencies

- [`@modelcontextprotocol/sdk`](https://github.com/modelcontextprotocol/typescript-sdk) — MCP server framework
- [`js-sha3`](https://github.com/emn178/js-sha3) — Keccak / SHA-3 hash implementations

## License

ISC