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Build a Chrome Extension That Shows Odds on Sports Articles

Reading a match preview on ESPN or BBC Sport? This extension detects team names and injects real-time odds directly into the page.

What You’ll Use

How It Works

Step 1: Manifest V3

Step 2: Background Script (API Calls)

Step 3: Content Script (Team Detection + Tooltip)

Step 4: Tooltip CSS

Rate Limit Math

  • Each unique team name found = 2 requests (search + odds)
  • Aggressive caching (5 min) means repeat visits cost 0
  • A typical article mentions 2-4 teams = 4-8 requests per page
  • Free tier handles ~1,000 article reads per month

Search API Reference

See search endpoint docs →

Get Your Free API Key

Start building in 5 minutes — 10,000 free requests/month

See Pricing

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