Free Blockchain APIs

Chainlink is a decentralized oracle network that connects smart contracts to real-world data like price feeds, random numbers, and external APIs.

Chainpoint anchors any data hash to the Bitcoin blockchain, creating a tamper-proof proof of existence for documents, records, or any digital content.

The Helium API provides access to legacy blockchain data for the Helium IoT network — hotspot locations, earnings, network coverage, and device activity.

Steem is a blockchain-based social media platform with a public API for reading posts, comments, votes, account data, and blockchain operations.

Walltime provides programmatic access to to retrieve walltime's market info via REST API.