tavily-proxy

A Cloudflare Worker that acts as an MCP (Model Context Protocol) proxy for the Tavily API. It provides the same tools as the official Tavily MCP server, but with an API key pool — automatically rotating through multiple Tavily keys and selecting the one with the most remaining credit.

Features

• MCP Server — Streamable HTTP transport at POST /mcp, compatible with any MCP client
• 4 Tavily Tools — tavily-search, tavily-extract, tavily-crawl, tavily-map
• API Key Pool — Multiple Tavily API keys stored in Cloudflare KV; each request picks the key with the highest remaining credit
• Key Management API — HTTP endpoints to add/delete keys and query their status
• Auth Protected — All endpoints (except health check) require an x-api-key header

Endpoints

All endpoints except GET / require the x-api-key header matching your configured AUTH_KEY.

Setup

Prerequisites

• Node.js v18+
• Wrangler CLI (npm install -g wrangler)
• A Cloudflare account

Local Development

# Install dependencies
npm install

# Set your auth key for local dev (already in .dev.vars)
# AUTH_KEY=test-secret-key

# Start local server
npm run dev

Wrangler simulates KV locally — no Cloudflare account needed for development.

Deploy to Production

1. Create a KV namespace:

   npx wrangler kv namespace create KV

1. Update `wrangler.toml` — replace YOUR_KV_NAMESPACE_ID with the real ID from step 1.

1. Set the auth secret:

   npx wrangler secret put AUTH_KEY

1. Deploy:

   npm run deploy

1. Add Tavily API keys to the pool:

   curl -X POST https://your-worker.workers.dev/api/keys \
     -H "Content-Type: application/json" \
     -H "x-api-key: your-auth-key" \
     -d '{"apiKey": "tvly-xxx"}'

Usage

Connect MCP Clients

With mcp-remote (for clients like Cursor, Claude Desktop, etc.):

{
  "mcpServers": {
    "tavily-proxy": {
      "command": "npx",
      "args": [
        "-y", "mcp-remote",
        "https://your-worker.workers.dev/mcp",
        "--header", "x-api-key:${AUTH_KEY}"
      ],
      "env": {
        "AUTH_KEY": "your-auth-key"
      }
    }
  }
}

Key Management

# Add a key (auto-queries remaining credit from Tavily)
curl -X POST https://your-worker.workers.dev/api/keys \
  -H "Content-Type: application/json" \
  -H "x-api-key: your-auth-key" \
  -d '{"apiKey": "tvly-xxx"}'

# List all keys and credits
curl https://your-worker.workers.dev/api/keys \
  -H "x-api-key: your-auth-key"

# Delete a key
curl -X DELETE https://your-worker.workers.dev/api/keys \
  -H "Content-Type: application/json" \
  -H "x-api-key: your-auth-key" \
  -d '{"apiKey": "tvly-xxx"}'

How the Key Pool Works

1. When a tool is called, KV.list() retrieves all stored API keys
2. The key with the largest remaining credit is selected
3. The request is proxied to api.tavily.com using that key
4. After the call, the estimated credit cost is deducted locally in KV
5. When a key is added via /api/keys, its real remaining credit is fetched from Tavily's /usage endpoint

License

ISC