Normally only key-controlled EOAs can start transactions. ERC-4337 enables smart-contract accounts via a separate "UserOperation" mempool and bundlers — no core protocol change. This unlocks features regular wallets can't have: social recovery, gas paid in tokens (or sponsored), batched actions, and custom security rules. It's a major step toward usable, recoverable crypto wallets.
Power-ups you unlock
Account abstraction without protocol changes
Smart-contract wallets via UserOperations
Enables social recovery, gas sponsorship, batching
Toward usable, recoverable wallets
Double-Spend Dan attacks — common mistakes
Confusing it with regular EOAs
Assuming it required a hard fork (it didn’t)
Overlooking the bundler/paymaster roles
Boss battleName two wallet features ERC-4337 enables that EOAs cannot.
Example code
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<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre>EOA: key signs, gas in ETH, no recovery
4337 account: social recovery · gas in USDC
batched actions · custom rules</pre></body></html>