market-feed

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market-feedUnified financial market data

One TypeScript client for Yahoo Finance, Alpha Vantage, Polygon.io, Finnhub, Twelve Data, and Tiingo — with caching, fallback, streaming, and React hooks built in.

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Six providers, one interface

Yahoo Finance (free), Alpha Vantage, Polygon.io, Finnhub, Twelve Data, and Tiingo. All return the same Quote, HistoricalBar, and CompanyProfile shapes regardless of which provider answers.

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Built-in LRU cache

Responses are cached automatically with smart per-method TTLs. Pluggable driver lets you swap in Redis, Upstash, or any key-value store.

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Automatic failover

Configure a provider chain and market-feed silently tries the next one if the first fails or hits a rate limit — no code changes needed.

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Real-time streaming

market-feed/ws delivers tick-by-tick WebSocket trade data from Polygon and Finnhub. market-feed/stream provides market-hours-aware HTTP polling that pauses overnight.

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Analysis toolkit

Technical indicators (SMA, EMA, RSI, MACD, Bollinger Bands, ATR, VWAP, Stochastic), portfolio P&L tracking, backtesting engine, price alerts, fundamentals, screener, options chains, and FRED macro indicators — all in one package.

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React hooks

useQuote, useStream, and useAlerts bring live market data directly into your React components with a single import. Requires React ≥ 18.

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Strict TypeScript

No any. Every response is fully typed with complete autocomplete. Works in Node 20+, Bun, Deno (via JSR), and Cloudflare Workers.

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Zero production dependencies

Uses only the native fetch API. Tree-shakable subpath exports — import only what you need. React is an optional peer dependency.

Quickstart ​

bash
npm install market-feed
ts
import { MarketFeed } from "market-feed";

const feed = new MarketFeed(); // zero-config — Yahoo Finance, no API key needed

const quote = await feed.quote("AAPL");
console.log(`${quote.symbol}: $${quote.price.toFixed(2)}`);
// AAPL: $189.84

That's it. No API keys, no boilerplate.

Subpath modules ​

ImportDescription
market-feedCore client + all six providers
market-feed/calendarOffline exchange calendar for 8 markets + crypto
market-feed/streamMarket-hours-aware HTTP polling async generator
market-feed/wsWebSocket streaming from Polygon / Finnhub
market-feed/consensusParallel multi-provider weighted price consensus
market-feed/indicatorsSMA, EMA, RSI, MACD, Bollinger Bands, ATR, VWAP, Stochastic
market-feed/portfolioLive P&L and unrealised gains tracking
market-feed/backtestPure-function backtesting engine
market-feed/alertsPrice / volume alert async generator
market-feed/fundamentalsIncome statements, balance sheets, cash flows
market-feed/screenerFilter symbols by price, volume, market cap, and more
market-feed/optionsOptions chains with Greeks from Polygon.io
market-feed/macroFRED macroeconomic indicators (CPI, GDP, Fed Funds…)
market-feed/reactuseQuote, useStream, useAlerts, useWebSocket, useOrderBook hooks (React ≥ 18 + React Native)
market-feed/browserCORS proxy utilities for browser-side use
market-feed/trpctRPC router + fetch-compatible HTTP handler
market-feed/cachePersistent cache drivers: Redis, Upstash, SQLite

Released under the MIT License.

Copyright © 2026 market-feed contributors