Blockchain¶
15 free Blockchain APIs — auth type, HTTPS and CORS support for each, so you can pick the right one without opening every docs page.
| API | Description | Auth | HTTPS | CORS |
|---|---|---|---|---|
| Bitquery | Onchain GraphQL APIs & DEX APIs | apiKey |
Yes | Yes |
| Blockscout | Multichain block explorer REST API (with Etherscan-compatible JSON-RPC) | apiKey |
Yes | No |
| Chainlink | Build hybrid smart contracts with Chainlink | No | Yes | Unknown |
| Chainpoint | Chainpoint is a global network for anchoring data to the Bitcoin blockchain | No | Yes | Unknown |
| ClearTrace | Cross-frontend DEX attribution and execution quality data across Ethereum and L2s | No | Yes | Yes |
| Covalent | Multi-blockchain data aggregator platform | apiKey |
Yes | Unknown |
| Etherscan | Ethereum explorer API | apiKey |
Yes | Yes |
| Get Started with Web3 | Bilingual Web3 lessons, glossary search and role-based learning paths | No | Yes | Yes |
| Helium | Helium is a global, distributed network of Hotspots that create public, long-range wireless coverage | No | Yes | Unknown |
| Nownodes | Blockchain-as-a-service solution that provides high-quality connection via API | apiKey |
Yes | Unknown |
| Steem | Blockchain-based blogging and social media website | No | No | No |
| TWZRD Agent Intel | Solana on-chain agent trust scoring via MCP; 4 free tools to score, resolve and verify AI agent wallets | No | Yes | Yes |
| The Graph | Indexing protocol for querying networks like Ethereum with GraphQL | apiKey |
Yes | Unknown |
| Walltime | To retrieve Walltime's market info | No | Yes | Unknown |
| Watchdata | Provide simple and reliable API access to Ethereum blockchain | apiKey |
Yes | Unknown |
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