INTRO

• TYPES OF CHAINLINK SERVICES

WHEN TO USE WHICH SERVICES

• WHY LINK ?

Chainlink cheat sheet decision tree:-

1. Do you need off-chain data?

• Yes → Which type?
  • 🔹 Market Prices (ETH/USD, BTC/USD, etc.) → Use Data Feeds (secure, decentralized prices every few mins).
  • 🔹 High-frequency prices (perpetuals, options, liquidations) → Use Data Streams (real-time, sub-second).
  • 🔹 Custom API data (weather, sports scores, IoT, social data, AI output, etc.) → Use Functions (serverless calls to any API + custom compute).

2. Do you need cross-chain messaging or token transfer?

• 🔹 Moving tokens/data between chains → Use CCIP (Cross-Chain Interoperability Protocol).
  • Ex: Transfer tokens Sepolia → Arbitrum.
  • Ex: Pass messages between Ethereum & Polygon.

3. Do you need randomness?

• 🔹 For lotteries, NFT traits, gaming outcomes, loot boxes, critical hits → Use VRF (Verifiable Random Function).
  • Cryptographically secure, tamper-proof randomness.

4. Do you need automation (timers / triggers)?

• 🔹 For periodic tasks → Use Automation (Keepers).
  • Example: Run lottery draw every 24 hours.
  • Example: Auto-liquidate unhealthy loans.
  • Example: Auto-execute savings yield.

5. Do you need proof of collateral or asset backing?