Chainlink vs Etherscan

Chainlink is best known as a decentralized oracle network whose core products (Data Feeds, Automation, Functions, VRF) are consumed on-chain by smart contracts rather than through a conventional web API, which is why this entry sat un-enriched for a long time. Data Streams is the one Chainlink product with a genuine off-chain HTTP surface: a low-latency REST endpoint (plus a companion WebSocket feed) that serves cryptographically-verifiable market-data reports, authenticated with an HMAC-signed API key rather than a bearer token. The mainnet endpoint bills per-report or via a subscription, payable in LINK or other supported assets; the same interface is free to call against a public testnet host for development and testing.

Etherscan's API exposes the same account balances, transactions, contract source, and gas-tracker data shown on the block explorer, addressed to Ethereum mainnet and its testnets through a single query-parameter-based endpoint. Calls against the older V1 endpoint now return a deprecation notice pointing at the documented V2 migration, so new integrations should build against V2 directly. Free-tier keys cover light use, with paid plans unlocking higher rate limits.