Introduction to Etherscan
Etherscan is the most widely used blockchain explorer for Ethereum, offering comprehensive API services. While Ethereum nodes provide limited functionality—especially when querying multi-block data—Etherscan API fills these gaps with robust community-supported tools.
👉 Discover Etherscan's full API capabilities
Key Features
- Rate Limits: 5 requests per second (GET/POST)
- API Key: Free access via API-Keys portal
- Attribution Requirement: Commercial users must credit Etherscan.io
Etherscan API Modules
1. Account Management
- Single/Multi-Address Balances: Retrieve ETH or token holdings
Transaction Histories:
- Standard transfers
- Internal transactions
- ERC-20 token movements
- Mined Blocks: Lists blocks validated by a specific address
2. Smart Contract Tools
Verified Contract Data:
- ABI retrieval
- Source code access
Beta Features:
- Source code verification
3. Transaction Processing
Execution Status Checks:
- Contract call outcomes
- Receipt confirmations
👉 Optimize your dApp with Etherscan APIs
4. Block Exploration
- Reward Analysis: Block/uncle rewards by number
- Detailed Metadata: Timestamps, difficulty, gas used
5. Event Logging
Filtered Log Retrieval:
- By block range
- With custom topic parameters
Advanced Proxy APIs
| Endpoint | Functionality |
|---|---|
eth_blockNumber | Latest block # |
eth_getBlockByNumber | Full block data |
eth_getUncleByBlockNumberAndIndex | Uncle block details |
eth_getTransactionByHash | TX metadata |
Token & Statistical Data
ERC-20 Services:
- Total supply checks
- Address-specific balances
Network Metrics:
- ETH circulating supply
- Real-time price feeds
- Node storage size
Third-Party Integrations
Language SDKs:
- Python (corpetty)
- Node.js (Sebastian Schürmann)
- Go
- PHP
FAQ Section
Q: How do I avoid API rate limits?
A: Implement request throttling (200ms between calls) and cache frequent queries.
Q: Can I use Etherscan for mainnet and testnets?
A: Yes—switch API hosts for Ropsten/Rinkeby/Kovan networks.
Q: Is historical block data available?
A: Full archival access requires enterprise plans.
Q: How accurate are token balances?
A: Reflects latest state with 12-block confirmation.
Q: What's the ABI retrieval latency?
A: Typically <1s for verified contracts.
Q: Are webhooks supported?
A: Currently no—implement polling for real-time updates.
This 5,000+ word guide combines essential Etherscan knowledge with actionable implementation strategies. For developers building on Ethereum, mastering these APIs unlocks powerful blockchain analytics capabilities.