Etherscan API
Read-only API for the Etherscan blockchain explorer, providing transaction history, contract ABI lookup, token transfers, gas prices, and verified contract source code.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Ethereum blockchain explorer API. Simple API key. Public blockchain data — low security risk. No PII involved. Rate limits enforced per key.
⚡ Reliability
Best When
You need transaction history, ABI lookup, or token transfer data for an Ethereum address without running your own indexer.
Avoid When
You need to write to the blockchain, require real-time streaming, or are working with non-Ethereum chains.
Use Cases
- • Fetching complete transaction history for any wallet address
- • Retrieving verified smart contract ABI for dynamic interaction
- • Monitoring ERC-20/ERC-721 token transfers for a wallet
- • Getting current gas price estimates for transaction planning
- • Looking up contract verification status and source code
Not For
- • Sending transactions (read-only API)
- • Real-time streaming of blockchain events
- • Non-Ethereum chains (use BSCScan, PolygonScan for other EVM chains)
Interface
Authentication
API key passed as query parameter. Single key per Etherscan account. Free tier allows no-key access at very low rate limits. Key improves rate limits significantly.
Pricing
Free tier is adequate for most agent prototyping. Paid tiers mainly increase rate limits and add priority support.
Agent Metadata
Known Gotchas
- ⚠ Success and error responses both return HTTP 200 - agents MUST check the 'status' field in response body
- ⚠ Transaction list endpoints return max 10,000 results even with offset pagination - large wallets require multiple strategies
- ⚠ Internal transactions are separate from normal transactions and require a different endpoint
- ⚠ API key in URL query string means it appears in server logs - use HTTPS and be mindful of log exposure
- ⚠ Rate limit errors return the same HTTP 200 with status:0 - not distinguishable from other errors without parsing message
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for Etherscan API.
Scores are editorial opinions as of 2026-03-06.