Petros Trading Scanner MCP

Read-only Model Context Protocol (MCP) server for short-term stock and ETF market research. It helps ChatGPT analyze futures, premarket movers, market breadth, sector strength, earnings, watchlist signals, and daily briefings.

This server does not place trades. Trade execution is handled separately (e.g. Robinhood). It does not store personal data or broker credentials.

Features

Tool	Description
get_futures	Nasdaq 100, S&P 500, Dow, Russell 2000, crude, gold, Bitcoin
get_premarket_movers	Leaders, laggards, most active (MarketWatch → Yahoo → Finviz fallback)
get_market_breadth	Finviz advancing/declining, highs/lows, SMA50/SMA200
get_finviz_snapshot	Homepage-style snapshot: movers, news, headlines, breadth, futures
get_earnings_calendar	Upcoming earnings (Finviz API)
get_watchlist_signals	Transparent 0–10 scores, bias, reasons, risk flags
get_semiconductor_strength	Sector score, bias, confidence, leaders/laggards for 11 semi names (SOXL workflow)
get_position_review	Single-position review for any symbol: action, confidence, thesis, strengths, risks
get_daily_briefing	Full briefing with source attribution, confidence, news severity, portfolio notes

Data sources (free/public)

1. Finviz — futures, breadth, snapshot, earnings API
2. Finnhub — optional primary quotes when FINNHUB_API_KEY is set
3. Alpha Vantage — optional quotes when ALPHA_VANTAGE_API_KEY is set
4. Nasdaq — quote provider (price, change %, volume)
5. Yahoo Finance — spark batch only when not rate-limited (30 min cooldown after HTTP 429)
6. MarketWatch — premarket movers (often blocked on cloud hosts with HTTP 401)
7. Yahoo Finance screeners — day gainers/losers/actives when MarketWatch is blocked

Caching: 5 minutes for market data, 15 minutes for daily briefings.

Watchlist quotes resolve in order: Finnhub → Alpha Vantage → Nasdaq → Yahoo (if not rate-limited) → Finviz. Yahoo is skipped for 30 minutes after HTTP 429. Check quoteDiagnostics.rateLimitedSources to see active blocks.

Note: MarketWatch frequently returns HTTP 401 from Heroku and other cloud servers due to bot protection. The server automatically falls back to Yahoo Finance, then Finviz. To skip MarketWatch entirely, set MARKETWATCH_ENABLED=false in Heroku config vars.

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Local development

Prerequisites

• Node.js 20+
• npm

Setup

git clone <your-repo-url>
cd mcp-trading
cp .env.example .env
npm install
npm run dev

Server starts on http://localhost:3000 by default.

• Health: GET /health
• MCP: POST /mcp (Streamable HTTP)

Scripts

Script	Purpose
npm run dev	Development with hot reload (tsx watch)
npm run build	Compile TypeScript to dist/
npm start	Run production build

Optional API key

Set MCP_SERVER_API_KEY in .env. When set, all /mcp routes require:

Authorization: Bearer <your-key>

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Deploy to Heroku

heroku create petros-trading-scanner
heroku config:set MCP_SERVER_API_KEY=your-secret-key
git push heroku main

Heroku sets PORT automatically. The app binds to 0.0.0.0 and uses process.env.PORT.

Verify deployment:

curl https://petros-trading-scanner.herokuapp.com/health

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Connect to ChatGPT Developer Mode

1. Deploy the server (Heroku or another HTTPS host).
2. In ChatGPT → Settings → Connectors / Developer Mode, add a custom MCP server.
3. Use your public MCP URL, for example:
   • https://petros-trading-scanner.herokuapp.com/mcp
4. If you configured MCP_SERVER_API_KEY, add the Bearer token in the connector auth settings.

The server implements Streamable HTTP (POST /mcp) compatible with ChatGPT Apps / Developer Mode.

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Example prompts

• "Use my Trading Scanner MCP to get today's daily briefing."
• "Check futures and premarket movers."
• "Analyze SOXL based on semiconductor strength."
• "Give me a market bias for today."
• "Run semiconductor strength for my SOXL workflow."
• "Run watchlist signals for SOXL, MU, NVDA, AMD, AVGO, INTC, MRVL, WDC."
• "Review my SOXL position — cost basis $50, current value $51.17."
• "Review my AAPL position — cost basis $180, current value $195."

Example: position review tool input

Works for any stock or ETF (SOXL, NVDA, AAPL, TQQQ, etc.):

{
  "symbol": "SOXL",
  "costBasis": 50,
  "currentValue": 51.17
}

Expected shape (values vary with live market data):

{
  "action": "hold",
  "confidence": 76,
  "thesis": "Semiconductor sector remains strong despite weak futures.",
  "strengths": ["..."],
  "risks": ["..."]
}

Example: daily briefing tool input

{
  "focusSymbols": ["SOXL", "MU", "NVDA", "AMD", "AVGO", "INTC", "MRVL", "WDC"],
  "portfolioContext": "Holding SOXL from starter account",
  "positions": [
    {
      "symbol": "SOXL",
      "costBasis": 50,
      "currentValue": 51.17
    }
  ]
}

The briefing now includes:

• sources.futuresSource, sources.premarketSource, sources.breadthSource, etc.
• confidence (0–100) alongside marketBias
• news[] with impact (high | medium | low) and sentiment
• portfolioNotes[] with thesis status per position
• semiconductorStrength summary block

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Scoring (transparent, not advice)

Market bias uses:

• Nasdaq 100 futures ±0.5%
• S&P 500 futures ±0.3%
• Advancing/declining breadth above 55%

Confidence (0–100) increases as the bias score moves away from neutral and more signals agree. Example: marketBias: "bearish" with confidence: 72 = moderately-to-strongly bearish, not a mild lean.

Semiconductor strength tracks NVDA, AMD, MU, AVGO, INTC, MRVL, WDC, TSM, AMAT, LRCX, SMCI. Strong if 5+ are positive premarket or in major news.

SOXL scoring considers semiconductor strength + Nasdaq futures direction. Leveraged ETF risk flags are always included.

Quote verification

Watchlist signals and semiconductor strength include extra fields so you can sanity-check prices:

Field	Meaning
price	Last regular (or premarket) sale from Yahoo/Nasdaq
previousClose	Prior session close used to compute change %
changePercent	Derived from price vs previousClose (or source-reported)
asOf	ISO timestamp of the quote (when available)
quoteSource	e.g. Yahoo Finance, Nasdaq, Finviz topGainers
quoteValidated	true when price, change, and % are internally consistent
dataFreshness	"fresh", "delayed", "stale", or "closed_session" — session-aware (premarket/regular/after-hours/weekend/holiday)
marketSession	Current US session: premarket, regular, after_hours, overnight, weekend, holiday
freshnessAgeMinutes	Minutes between asOf and server time
freshnessReason	Human-readable explanation of the freshness classification
providerTimestamps	Per-provider debug: finnhub.t, nasdaq.lastTradeTimestamp, etc.
sourceQuality	"multi_source_agreement", "multi_source_partial", "finnhub_only", "nasdaq_only", "finviz_only", etc.
confidence	Primary+Nasdaq agreement=95, partial agreement=85, Nasdaq only=70, Finviz only=55
isDelayed	true for Finviz-only fallback quotes (change % only)

Parser note: Nasdaq quotes use primaryData.lastSalePrice — not market cap, 52-week high, or volume. If a price looks wrong, check previousClose and asOf: when change % looks realistic but the level seems off, the upstream feed (Yahoo/Nasdaq) may be reporting a different session or a forward-dated close. Cross-check with your broker.

Daily briefings also include top-level dataFreshness — aggregated from futures, premarket, breadth, and watchlist quotes (stale if any quote is stale; closed_session when all quotes reflect the last completed session).

get_watchlist_signals returns overall confidence, quoteDiagnostics (including rateLimitedSources and providersAttempted).

The tools return data, scores, and reasons only — not buy/sell recommendations. ChatGPT interprets the output; you make your own decisions.

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Project structure

src/
  index.ts
  server.ts
  mcp/
    tools.ts
    schemas.ts
  services/
    finviz.ts
    marketwatch.ts
    yahoo.ts
    scoring.ts
    marketData.ts
    cache.ts
    http.ts
  types/
    market.ts
  utils/
    parseNumber.ts
    logger.ts
    quoteValidation.ts
    newsAnalysis.ts
    dataFreshness.ts
    quoteConfidence.ts

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Disclaimer

Development note: This is a research assistant only. It does not provide financial advice and does not place trades. Market data may be delayed or incomplete. Always verify quotes and consult your own judgment before trading.