tx-explain

type	Skill
mode	read-only
name	Tx Explain
category	basics
description	Decode any Base transaction into a plain-English story - method, token movements, swaps/approvals, counterparties, and suspicious-approval flags. Keyless via Base RPC + Etherscan v2.
var
tags	["crypto","base"]
requires	["ETHERSCAN_API_KEY?"]
capabilities	["external_api","sends_notifications"]

${var} — Transaction hash (0x..., 66 chars) on Base. Required. If empty, log TX_EXPLAIN_NO_TARGET and exit cleanly (no notify).

Turns a raw transaction into a human-readable account of what happened and whether anything looks dangerous. Runs keyless on public endpoints.

Config

• Target = ${var}. Chain = Base (chainid=8453, explorer basescan.org).
• ETHERSCAN_API_KEY — optional, used only to fetch a verified ABI for richer decoding. Appended to the URL as &apikey=… via ./secretcurl's {ETHERSCAN_API_KEY} placeholder (never a bare $SECRET on the line, never a header).

Steps

1. Fetch tx + receipt

TX="${var}"
curl -m 10 -s -X POST "https://mainnet.base.org" -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_getTransactionByHash","params":["'"$TX"'"],"id":1}' | jq '.result'
curl -m 10 -s -X POST "https://mainnet.base.org" -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_getTransactionReceipt","params":["'"$TX"'"],"id":1}' | jq '.result'

Record: from, to, native value, status (success/revert), gas used, block/time.

2. Decode the method

Take the first 4 bytes of input (the selector). Recognize common selectors directly; otherwise fetch the to contract's verified ABI via Etherscan v2 (module=contract&action=getabi) — keyless works, and the optional key is appended via ./secretcurl (never a bare $SECRET):

TO="<the tx's `to` contract address from step 1>"
KEYQ=; [ -n  ] && KEYQ=
./secretcurl -m 10 -s  | jq -r