TIL that mempool.space uses Esplora’s /tx/:txid/outspend/:vout API to show the transaction that spent an output on its bow tie chart. I didn’t even know Esplora existed until I looked to see how they did that.
I also learned how to call the Electrum scripthash based RPC calls by checking to see how mempool.space does it.
Open Source is a godsend. Documentation never tells these stories as well as working code does.