ferdousbhai/tasty-agent

Fix: VIX (and similar calculated indices) quote streaming

Root cause: VIX doesn't publish Quote events in dxFeed. Unlike SPX (where Cboe computes bid/ask from its 500 component stocks), VIX is a derived volatility index with no tradable components — it only publishes Trade events (the current index value).

The fix: For index symbols, we now subscribe to both Quote and Trade events, racing them. Quote is preferred when available (e.g., SPX gets full bid/ask spread), but Trade is accepted as a fallback (e.g., VIX gets the last index value).

Also fixed the TODO comment to reference the correct upstream issue (tastyware/tastytrade#322).

Expected results

| Call | Expected |
|------|----------|
| get_quotes([{"symbol": "SPX", "instrument_type": "Index"}]) | ✅ Quote (bid/ask spread) |
| get_quotes([{"symbol": "VIX", "instrument_type": "Index"}]) | ✅ Trade (last index value) |
| get_quotes([{"symbol": "AAPL"}, {"symbol": "/ESM6"}, {"symbol": "VIX", "instrument_type": "Index"}]) | ✅ Mixed — each symbol gets the best available event |

Update

{
  "mcpServers": {
    "tastytrade": {
      "command": "uvx",
      "args": ["--from", "tasty-agent>=3.3.6", "tasty-agent"],
      "env": { ... }
    }
  }
}