Toss Invest MCP

A personal MCP server for the Toss Securities Open API. It lets any MCP client read market data and your account, and (optionally) place real-money orders.

Built with FastMCP; runs locally over stdio.

Setup

1. Add credentials — create .env in the project root with keys from

Toss Securities WTS (Settings → Open API):

   API_KEY="tsck_live_..."      # client_id
   SECRET_KEY="tssk_live_..."   # client_secret
   # TOSS_ACCOUNT_SEQ=          # optional: default account
   # TOSS_ENABLE_TRADING=true   # optional: allow placing orders

1. Install — uv sync

1. Connect your MCP client — point any MCP client at the server using this command:

   uv run --directory /path/to/toss-invest-mcp toss-invest-mcp

Or in your client's JSON config:

   {
     "mcpServers": {
       "toss-invest": {
         "command": "uv",
         "args": ["run", "--directory", "/path/to/toss-invest-mcp", "toss-invest-mcp"]
       }
     }
   }

Tools

Market data: get_prices, get_orderbook, get_trades, get_candles, get_price_limits, get_stocks, get_stock_warnings, get_exchange_rate, get_kr_market_calendar, get_us_market_calendar

Account: get_accounts, get_holdings, get_buying_power, get_sellable_quantity, get_commissions, get_orders, get_order

Trading (only when TOSS_ENABLE_TRADING=true): create_order, modify_order, cancel_order

Account tools take an account_seq — call get_accounts to find yours, or set TOSS_ACCOUNT_SEQ in .env.

Safety

• Trading tools place real-money orders and are off by default — they only work with

TOSS_ENABLE_TRADING=true.

• Orders ≥ 100M KRW require confirm_high_value_order=true.
• Credentials stay in your local .env (git-ignored); nothing is hosted.