Blockchair

provider

create("blockchair")

auth

optional BLOCKCHAIR_API_KEY

chains

Bitcoin, Ethereum, eCash

capabilities

balance, history, tx detail, block

endpoint

api.blockchair.com

default chain

ethereum

Address it

const blockchair = await create("blockchair"); // BLOCKCHAIR_API_KEY is optional
await blockchair.getBalance("1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "bitcoin");

The key is optional. Set BLOCKCHAIR_API_KEY and Blockchair joins the configured tier of provider selection; leave it unset and it stays a keyless candidate that shows up in the fallback pass, after Mempool on Bitcoin.

What it reads

/{chain}/dashboards/address/:address for balance and history, /{chain}/dashboards/transaction/:hash for one transaction, /{chain}/dashboards/block/:number for a block. Balances, history, details and blocks; no contracts, tokens or gas.

Gotchas

• The data format differs between the UTXO chains and Ethereum, and the provider maps both. eCash amounts are satoshis at two decimals, so 100 satoshis is 1 XEC.
• The dashboard answer carries context.state, the chain height when it was built, and that is what Balance.blockNumber shows. Every other provider's balance endpoint says nothing about a block.
• funded and spent are the address's cumulative received and spent totals, in satoshis.

Where it lives

src/providers/blockchair.ts.