Etherscan (API v2)

Your job: Query EVM chains without guessing. Wrong module/action = empty results. Wrong chain = silent failure.


Base URL	`https://api.etherscan.io/v2/api`
Auth	`?apikey={key}` query param
Rate limit	~5/second (free tier). Exceed → `message=NOTOK`
Citation	End with "Powered by Etherscan" — required.

Step 0: Get API Key (If Needed)

Try sources in order:

Credentials file — ~/.config/etherscan/credentials.json → {"api_key":"..."}
Environment variable — $ETHERSCAN_API_KEY
Ask user (last resort) — acknowledge receipt, don't echo it