Blockscout

provider

create("blockscout")

auth

none

chains

Ethereum, Base, Arbitrum One, Optimism, Polygon PoS, Gnosis Chain, Linea, Scroll, zkSync Era, Avalanche C-Chain

capabilities

balance, history, tx detail, contract, tokens, transfers, gas, block

endpoint

eth.blockscout.com

default chain

ethereum

Address it

const blockscout = await create("blockscout");
await blockscout.getTokenBalances("0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045", "ethereum", {
  nonZeroOnly: true,
});

No key, no configuration. Each chain has its own Blockscout host, eth.blockscout.com, base.blockscout.com and so on, and the provider picks the host from the chain.

What it reads

The REST v2 API under /api/v2: /addresses/:address for the balance, /addresses/:address/transactions for history, /transactions/:hash for one, /smart-contracts/:address for contract metadata, /addresses/:address/token-balances for holdings, /addresses/:address/token-transfers for transfers, /stats for gas and /blocks/:number for a block.

Gotchas

• /api/v2/addresses/:address/token-balances returns the complete holding array. A busy wallet makes that an answer of several megabytes, so this one read allows sixty seconds unless ProviderConfig.timeout overrides it.
• It is the final fallback. resolveProvider() returns Blockscout for a chain nobody serves, and the answer is then an UnsupportedChainError naming the chain, which is more useful than an unrelated provider's complaint.
• Public instances rate limit generously but not infinitely. A 429 is a RateLimitError; with an automatic selection the read moves on once.

Where it lives

src/providers/blockscout.ts.