ENS Resolver API
Resolve ENS names to ETH addresses and reverse -- avatar URLs included. Identity layer for agents. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.
Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.
Quickstart -- MCP
Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):
{
"mcpServers": {
"ens-resolver": {
"url": "https://ens-resolver.api.klymax402.com/mcp"
}
}
}
Quickstart -- HTTP (x402)
curl -X POST "https://ens-resolver.api.klymax402.com/api/resolve" \
-H "Content-Type: application/json" \
-d '{}'
# -> 402 Payment Required, with an x402 payment challenge in the response body
Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.
Tools
| Tool | Method | Path | Price | Description |
|---|---|---|---|---|
crypto_resolve_ens | POST | /api/resolve | $0.005 | Resolve ENS name to Ethereum address or reverse-resolve address to ENS name |
crypto_resolve_ens
Use this when you need to resolve an ENS name to an Ethereum address, or reverse-resolve an address to its ENS name. Returns resolution data in JSON.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
name | string | no | ENS name to resolve (e.g. vitalik.eth) |
address | string | no | Ethereum address for reverse resolution (e.g. 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045) |
Returns
address-- resolved Ethereum address (0x...)ensName-- ENS name (e.g. vitalik.eth)avatar-- avatar URL associated with the ENS name (if set)resolvedDirection-- "forward" (name to address) or "reverse" (address to name)
Example response:
{"address":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","ensName":"vitalik.eth","avatar":"https://...","resolvedDirection":"forward"}
When to use: sending funds to an ENS name to verify the correct address. Essential for identity resolution and human-readable wallet lookup.
Not for: wallet balances (use wallet_get_portfolio), token safety (use token_check_safety), NFT metadata (use crypto_get_nft_metadata).
Example agent prompts
- "Resolve an ENS name to an Ethereum address, or reverse-resolve an address to its ENS name"
Payment
- Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
- Network: Base L2 (
eip155:8453) - Asset: USDC
- Facilitator: Coinbase CDP (primary), PayAI (fallback)
- Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)
Part of klymax402
100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.
- Catalog: https://klymax402.com/llms.txt
- Full API reference: https://klymax402.com/llms-full.txt
- Live stats: https://klymax402.com/stats
License
MIT