Kagi Translate MCP Server

An MCP server that exposes Kagi Translate as tools for any MCP-compatible assistant. It is BYOK: set your own KAGI_API_KEY and the server calls Kagi’s Translate API over stdio.

Tools

• translate_text - translate plain text or batch text inputs
• translate_url - translate content fetched from a URL
• proofread - proofread and correct text

Requirements

• Node.js 20 or newer
• A Kagi API key in KAGI_API_KEY

Kagi’s translate service is currently in a free test period. If you need a key, email support@kagi.com.

Setup

npm install
cp .env.example .env

Edit .env and set your real API key:

KAGI_API_KEY=your_real_key_here

Build

npm run build

This compiles TypeScript into dist/.

Run

npm start

For local development with rebuilds:

npm run dev

This command builds once, watches src/ for changes, and restarts the server automatically.

Claude Desktop Configuration

Add the server to claude_desktop_config.json and point it at the built entry point:

{
  "mcpServers": {
    "kagi-translate": {
      "command": "node",
      "args": ["/absolute/path/to/kagi-translate-mcp/dist/index.js"],
      "env": {
        "KAGI_API_KEY": "your_real_key_here"
      }
    }
  }
}

If you prefer to keep secrets out of the config file, start Claude Desktop with KAGI_API_KEY already present in the environment and omit the env block.

Assumptions

The public Kagi docs page is authenticated, so this implementation assumes the confirmed quick-start request shape for translation and conservative optional fields for advanced controls. The code currently sends these payloads:

• POST /api/translate with text or texts, source_lang, target_lang, and optional formality, gender, and context
• POST /api/translate-url with url, source_lang, target_lang, and optional formality, gender
• POST /api/proofread with text and optional language or target_lang

If Kagi’s authenticated docs differ on field names or response shapes, update src/kagi/types.ts and the tool request mapping in src/tools/.

Implementation Notes

• All outbound Kagi requests go through src/kagi/client.ts.
• Tool inputs are validated with Zod and inferred from the schemas.
• Logging uses console.error only; stdout is reserved for MCP protocol traffic.
• Each tool lives in its own file under src/tools/ and is registered from src/tools/index.ts.