Koios

Address it

const koios = await create("koios");
await koios.getTokenBalances("addr1…", "cardano");

What it reads

Koios answers on POST with the address or hash in the request body: address_info for the balance, address_txs then tx_info for history, tx_info for one transaction, address_assets for native token holdings.

Gotchas

• The public instance rejects a body over 5120 bytes and one hash costs about 67 of them, so getTxHistory asks tx_info for seventy hashes at a time and reorders the answer, which comes back in the endpoint's own order.
• address_info ships the whole UTxO set of an address, 222 kB for a busy one. getBalance narrows the payload with the PostgREST select parameter, but the endpoint still builds the set before it answers, so a busy address takes seconds against the client timeout of fifteen. Slow, not broken.
• The phase-2 validity flag sits behind the heavier _scripts payload, so a transaction reads as success even when a failing script consumed its collateral. isContractInteraction comes from the presence of collateral inputs.
• Lovelace, six decimals. funded and spent are the address totals.

Where it lives

src/providers/koios.ts.