Blockchain APIs let you add blockchain capabilities without building from scratch. Every entry below is profiled with trust signals — pricing model, authentication requirements, CORS support, rate limits, and live uptime checks — so you can compare options and pick production-safe choices instead of guessing from a link list.
| API | Pricing | Auth | CORS | Health | |
|---|---|---|---|---|---|
| 1inch Decentralized exchange aggregator API for token swaps across multiple DEX protocols | Free | No | Yes | Profile | |
| Alchemy Ethereum Ethereum Node-as-a-Service providing JSON-RPC access to Ethereum mainnet and testnets | Free | API Key | No | Profile | |
| Bitquery Onchain GraphQL APIs & DEX APIs | Free | API Key | No | Profile | |
| Blockscout API Multichain block explorer REST API (with Etherscan-compatible JSON-RPC) | Paid | API Key | No | Profile | |
| Bscscan Binance Smart Chain explorer API | Free | API Key | No | Profile | |
| Chainlink Build hybrid smart contracts with Chainlink | Free | No | No | Profile | |
| Chainpoint Chainpoint is a global network for anchoring data to the Bitcoin blockchain | Free | No | No | Profile | |
| ClearTrace API Cross-frontend DEX attribution and execution quality data across Ethereum and L2s | Unknown | Unknown | Yes | Profile | |
| Covalent Multi-blockchain data aggregator platform | Freemium | API Key | No | Profile | |
| Etherscan Ethereum explorer API | Freemium | API Key | No | Profile | |
| Get Started with Web3 API Bilingual Web3 lessons, glossary search and role-based learning paths | Unknown | Unknown | Yes | Profile | |
| GetBlock Blockchain RPC Node provider that supports over 50 multiple blockchains | Free | API Key | No | Profile | |
| Helium API Helium is a global, distributed network of Hotspots that create public, long-range wireless coverage | Unknown | Unknown | Unknown | Profile | |
| INFURA Ethereum Ethereum Node-as-a-Service providing JSON-RPC access to Ethereum mainnet and testnets via Infura | Free | API Key | Yes | Profile | |
| Layer4 Layer4 is a blockchain integration platform that supports no-code and API use | Free | API Key | Yes | Profile | |
| Nownodes Blockchain-as-a-service solution that provides high-quality connection via API | Free | API Key | No | Profile | |
| Solana JSON RPC JSON-RPC API for interacting with the Solana blockchain network | Free | No | No | Profile | |
| Steem Blockchain-based blogging and social media website | Free | No | Yes | Profile | |
| TWZRD Agent Intel API Solana on-chain agent trust scoring via MCP; 4 free tools to score, resolve and verify AI agent wallets | Free | Unknown | Yes | Profile | |
| The Graph Indexing protocol for querying networks like Ethereum with GraphQL | Free | API Key | No | Profile | |
| Tron Network REST API for interacting with the TRON blockchain network including smart contracts and transactions | Free | No | No | Profile | |
| Watchdata Provide simple and reliable API access to Ethereum blockchain | Free | API Key | No | Profile | |
| ZMOK Ethereum JSON-RPC API and Web3 provider for decentralized applications | Free | No | No | Profile | |
| blockfrost Cardano REST API for interacting with the Cardano blockchain mainnet and testnets | Free | API Key | Yes | Profile |
Start with pricing and auth: free tiers and no-auth APIs are fastest to prototype with. Then check CORS if your app calls the API from the browser, and health before you commit — a great API that's been down for a week will block your launch. Each profile below shows all of these signals plus rate limits where documented.