In the rapidly evolving world of blockchain development, access to reliable, scalable, and well-documented APIs is essential. Whether you're building decentralized applications (dApps), analyzing on-chain data, or integrating smart contracts, the right blockchain API can significantly accelerate your development cycle. This guide explores the top 13 blockchain APIs that empower developers with real-time data, cross-chain compatibility, and seamless integration—without requiring deep infrastructure setup.
What Are Blockchain APIs?
Blockchain APIs are interfaces that allow developers to interact with blockchain networks without running full nodes. They enable actions like retrieving transaction data, querying smart contract states, broadcasting transactions, and monitoring wallet activity—all through simple HTTP requests.
These tools are critical for scaling blockchain applications efficiently while maintaining performance and security.
Core Blockchain APIs Every Developer Should Know
1. Bitquery – Onchain GraphQL APIs & DEX APIs
Bitquery offers powerful GraphQL-based APIs for querying data across multiple blockchains, including Ethereum, Binance Smart Chain, and Solana. Its strength lies in its ability to extract complex on-chain data—such as decentralized exchange (DEX) trades, token transfers, and NFT transactions—with minimal query overhead.
👉 Discover how GraphQL-powered blockchain queries can simplify your dApp development
2. BscScan – Binance Smart Chain Explorer API
As one of the most widely used block explorers for BSC, BscScan provides a robust public API for fetching block details, transaction logs, contract metadata, and token balances. It’s ideal for developers building on Binance Smart Chain who need fast, accurate data access.
With support for verified smart contracts and event tracking, BscScan streamlines debugging and monitoring.
3. Chainlink – Build Hybrid Smart Contracts
Chainlink is more than just an oracle network—it's a foundational tool for creating hybrid smart contracts that connect on-chain logic with off-chain data and systems. Developers use Chainlink to securely bring real-world data (like price feeds or weather information) into their smart contracts.
Its decentralized architecture ensures reliability and tamper resistance.
4. Chainpoint – Anchor Data to Bitcoin
Chainpoint enables verifiable data integrity by anchoring digital records (e.g., documents, timestamps, certificates) directly to the Bitcoin blockchain. This creates immutable proof of existence at a specific time.
Use cases include academic credentialing, supply chain tracking, and legal document verification.
5. Covalent – Multi-Blockchain Data Aggregator
Covalent unifies data from over 200 blockchains into a single API endpoint. Developers can retrieve comprehensive portfolio holdings, NFT metadata, transaction histories, and gas fees across chains like Ethereum, Polygon, Avalanche, and more.
This cross-chain visibility makes Covalent a go-to choice for multi-chain analytics platforms and wallet integrations.
6. Etherscan – Ethereum Explorer API
Etherscan remains the gold standard for Ethereum data access. Its API allows developers to fetch transaction details, verify contracts, monitor addresses, and track internal calls—all in real time.
It also supports bytecode verification and event log parsing, making it indispensable for Ethereum-based development.
7. GetBlock – RPC Node Provider for 50+ Blockchains
GetBlock eliminates the need to manage your own nodes by offering instant access to RPC endpoints across more than 50 blockchains. From Bitcoin and Ethereum to newer L1s like Aptos and Sui, GetBlock delivers low-latency connections with high uptime.
👉 See how you can deploy blockchain nodes in seconds without server management
8. Helium – Decentralized Wireless Network
Helium leverages blockchain to power a decentralized IoT network where users operate Hotspots to provide long-range wireless coverage. The Helium API allows developers to access blockchain data related to Hotspot rewards, location proofs, and data transmission events.
Ideal for building decentralized IoT applications or location-based services.
9. Layer4 – No-Code & API Blockchain Integration
Layer4 simplifies blockchain integration with both no-code tools and developer-first APIs. It supports popular chains like Ethereum and Solana and enables quick connection to wallets, smart contracts, and transaction pipelines.
Perfect for startups and non-technical teams looking to integrate blockchain functionality rapidly.
10. Nownodes – High-Quality Blockchain-as-a-Service
Nownodes offers reliable blockchain-as-a-service (BaaS) solutions with API access to major networks including Bitcoin, Litecoin, Dogecoin, and Ethereum. Each node is fully synchronized and maintained for high availability.
Its enterprise-grade infrastructure suits financial institutions and trading platforms needing stable node access.
11. Steem – Blockchain-Based Social Media
Steem powers a decentralized social media ecosystem where users earn cryptocurrency for content creation and engagement. The Steem API lets developers build custom frontends, analyze user activity, or create content moderation bots.
Popular among Web3 social app developers and community platforms.
12. The Graph – Indexing Protocol for Querying Networks
The Graph revolutionizes how dApps access blockchain data by indexing it into easily queryable formats using GraphQL. Instead of scanning entire chains, developers can query specific events—like Uniswap trades or Aave loans—with precision.
Numerous subgraphs are already available for major DeFi protocols.
13. Watchdata – Simple & Reliable Ethereum API
Watchdata focuses on delivering clean, stable API access to the Ethereum blockchain. With straightforward documentation and consistent uptime, it’s especially useful for beginners or small projects needing dependable Ethereum data without complexity.
Supports JSON-RPC methods and event listening capabilities.
Frequently Asked Questions (FAQ)
Q: What is the main benefit of using blockchain APIs instead of running my own node?
A: Using blockchain APIs saves time, reduces infrastructure costs, and provides instant scalability. Running your own node requires significant technical expertise, hardware investment, and ongoing maintenance—APIs abstract this away.
Q: Are these APIs free to use?
A: Many offer free tiers with rate-limited access suitable for testing or small projects. However, production-grade usage typically requires paid plans for higher request volumes and premium features like priority support or dedicated nodes.
Q: Which API is best for multi-chain dApp development?
A: Covalent and GetBlock stand out for multi-chain support. Covalent excels in unified data retrieval across chains, while GetBlock provides direct RPC access to over 50 networks—ideal for deploying cross-chain applications.
Q: Can I use these APIs for real-time transaction monitoring?
A: Yes. APIs like Etherscan, BscScan, and Watchdata support real-time event polling and webhook integrations that notify your app when specific transactions occur.
Q: Do any of these APIs support NFT data?
A: Absolutely. Covalent, The Graph, and Bitquery all provide detailed NFT metadata retrieval, ownership history, transfer tracking, and collection-level analytics.
Q: How do I choose the right blockchain API for my project?
A: Consider your target blockchain(s), required data types (transactional, analytical, real-time), scalability needs, and technical resources. For example, use Chainlink if you need oracles; pick The Graph for efficient querying; go with GetBlock if you want plug-and-play node access.
Final Thoughts
The future of decentralized development hinges on accessible infrastructure—and blockchain APIs are at the heart of that evolution. From querying Ethereum smart contracts to anchoring data on Bitcoin or building hybrid oracles with Chainlink, these tools empower developers to innovate faster and smarter.
Whether you're launching a DeFi protocol, analyzing on-chain behavior, or connecting physical devices via Helium’s IoT network, there’s a robust API solution ready to support your vision.
👉 Accelerate your blockchain development journey with seamless API access today