feat: add Alpha Vantage as primary market data source (replace Yahoo Finance + Finnhub)

[koala73]

Why Alpha Vantage

WorldMonitor currently uses two free market data sources with known reliability issues:

Source	Problem
Yahoo Finance	IP-level 429s on Vercel requiring Railway relay workaround; 15–30 min delay on commodity futures (NYMEX/COMEX); unofficial scraper-based access — no SLA
Finnhub (free)	Burst-sensitive (429s above ~10 req/min); US stocks only; no indices, no commodities, no futures

Alpha Vantage at $49.99/month solves both with a single licensed API key.

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What Alpha Vantage covers at entry tier ($49.99/mo)

Asset class	Coverage
US stocks	Real-time quotes
Indices	S&P 500, Dow, Nasdaq, VIX
Commodity futures	Gold (GC=F), WTI Crude (CL=F), Natural Gas (NG=F), Silver (SI=F), Copper (HG=F)
Forex	Real-time currency pairs
Crypto	Intraday real-time
ETFs	Real-time US ETFs
Extended hours	Pre/post market data
News + AI sentiment	Per-ticker sentiment scores
Economic indicators	Built-in series
Fundamentals	Earnings, income statements, ratios

Rate limit: 75 req/min with REALTIME_BULK_QUOTES supporting up to 100 symbols per call → ~7,500 symbols/minute effective throughput. WM's polling-every-minute architecture maps directly to this.

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Why this beats the current stack

• No IP rate limiting — dedicated API key, not shared Vercel IP pool
• No Railway relay needed for market data fetches
• Real-time commodity futures — fixes 30-min NYMEX/COMEX delay from Yahoo
• One API key, all asset classes — no more Finnhub + Yahoo + relay complexity
• Official licensed data — SLA-backed, not scraper-dependent
• Cost: $49.99/mo vs $0 current, but eliminates engineering overhead of the Yahoo/Finnhub reliability workarounds

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What stays unchanged

• CoinGecko — crypto sector market cap breakdown (AV covers prices, not sector aggregates)
• FRED / EIA / BIS — macro/economic series (unrelated to market quotes)

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Implementation outline

1. Register at https://www.alphavantage.co/ and obtain ALPHA_VANTAGE_API_KEY
2. Add key to Railway + Vercel env vars
3. Replace Yahoo Finance fetcher in server/worldmonitor/market/v1/_shared.ts with AV REALTIME_BULK_QUOTES endpoint
4. Update scripts/seed-market-quotes.mjs — batch symbols into groups of 100, single AV call per batch
5. Update scripts/seed-commodity-quotes.mjs — switch from Yahoo GC=F/CL=F symbols to AV physical commodity endpoints
6. Update scripts/seed-etf-flows.mjs — AV ETF quotes
7. Keep Finnhub as optional fallback or deprecate entirely
8. Remove Railway relay Yahoo proxy route once migration is validated

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API Documentation

• Main docs: https://www.alphavantage.co/documentation/
• Real-time bulk quotes: https://www.alphavantage.co/documentation/#realtime-bulk-quotes
• Commodities: https://www.alphavantage.co/documentation/#commodities
• Forex: https://www.alphavantage.co/documentation/#fx-intraday
• Crypto: https://www.alphavantage.co/documentation/#crypto-intraday
• News + sentiment: https://www.alphavantage.co/documentation/#news-sentiment
• Technical indicators: https://www.alphavantage.co/documentation/#technical-indicators
• Fundamental data: https://www.alphavantage.co/documentation/#fundamentals

Pricing

https://www.alphavantage.co/premium/