Blockscout
HTTPS No CORS apiKey
Multichain block explorer REST API (with Etherscan-compatible JSON-RPC)
API Endpoint
https://dev.blockscout.com/More Blockchain APIs
Onchain GraphQL APIs & DEX APIs
HTTPS CORS apiKey
Build hybrid smart contracts with Chainlink
HTTPS CORS ? Free
Chainpoint is a global network for anchoring data to the Bitcoin blockchain
HTTPS CORS ? Free