MCP API Key Auth

Purpose

Enable external MCP clients (Claude Code, Cursor, etc.) to authenticate with the stock data service using independent API keys, and track per-tool usage (table name, record count) for monitoring.

When to Use

• User wants to create or manage MCP API keys
• User wants to configure an external MCP client to connect to this service
• User wants to view MCP tool usage statistics (which tools called, which tables queried, how many records)
• User needs to troubleshoot MCP authentication errors (401, invalid key, expired key)

Architecture

• API Key management is on the HTTP server (port 8000), protected by JWT login
• MCP protocol is on the MCP server (port 8001), protected by API key in request headers
• Usage tracking records are stored in ClickHouse mcp_tool_usage_log table

Workflow

1) Create an API Key

First login to get a JWT token, then create an API key:

# Login
JWT=$(curl -s -X POST http://<host>:8000/api/auth/login \
  -H "Content-Type: application/json" \
  -d '{"email":"your@email.com","password":"yourpassword"}' \
  | python3 -c "import sys,json; print(json.load(sys.stdin)['access_token'])")

# Create API key
curl -s -X POST http://<host>:8000/api/mcp-keys/create \
  -H "Authorization: Bearer $JWT" \
  -H "Content-Type: application/json" \
  -d '{"key_name": "my-cursor-key", "expires_days": 90}'

The response contains the full API key (e.g., sk-a1b2c3d4...). Save it immediately — it is only shown once.

2) Configure MCP Client

Claude Code / Claude Desktop

Add to your MCP configuration (claude_desktop_config.json or project .mcp.json):

{
  "mcpServers": {
    "stock-data": {
      "url": "http://<host>:8001/messages",
      "transport": "streamable-http",
      "headers": {
        "Authorization": "Bearer sk-your-api-key-here"
      }
    }
  }
}

Cursor

In Cursor settings, add an MCP server with:

• URL: http://<host>:8001/messages
• Header: Authorization: Bearer sk-your-api-key-here

3) Verify Connectivity

# Should return tool list (not 401)
curl -s -X POST http://<host>:8001/messages \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-your-api-key-here" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

4) View Usage Statistics

# Usage history (paginated)
curl -s "http://<host>:8000/api/mcp-usage/history?page=1&page_size=20" \
  -H "Authorization: Bearer $JWT"

# Aggregated stats (last 30 days)
curl -s "http://<host>:8000/api/mcp-usage/stats?days=30" \
  -H "Authorization: Bearer $JWT"

5) Manage API Keys

# List all keys
curl -s http://<host>:8000/api/mcp-keys/list \
  -H "Authorization: Bearer $JWT"

# Revoke a key
curl -s -X POST http://<host>:8000/api/mcp-keys/revoke \
  -H "Authorization: Bearer $JWT" \
  -H "Content-Type: application/json" \
  -d '{"key_id": "<key-id>"}'

Key Endpoints

Troubleshooting

• 401 "API key required": Missing Authorization header on MCP calls
• 401 "Invalid or expired API key": Key was revoked or expired — create a new one
• initialize works but tools/list fails: initialize does not require auth; tools/list and tools/call do
• Usage not showing up: Usage logging is fire-and-forget; check ClickHouse mcp_tool_usage_log table directly

Verification Checklist

• API key created and full key returned (shown only once)
• tools/list returns 401 without API key
• tools/list returns tool list with valid API key
• tools/call records usage in mcp_tool_usage_log table
• Revoked key returns 401 on subsequent calls
• Usage history API returns correct data
• Usage stats show daily call counts and top tools