Reading the Chain
Tokens, NFTs & reading a contract
Lesson 5 of 5
A token is a contract that keeps a balance mapping. Call its functions by hand with eth_call, decode the 32-byte answers, and the ABI stops being a mystery.
What you'll learn
- Explain an ERC-20 token and an ERC-721 NFT as contract state, not as files or coins
- Encode a function call by hand: 4-byte selector plus 32-byte padded arguments
- Read a live stablecoin's decimals, total supply and a balance with eth_call
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Not sure yet? Try the free lesson first: What a blockchain actually is