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Agentshelf Ethereum eth_call
x402
Agentshelf Ethereum eth_call is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-21).
Executes a read-only Ethereum mainnet eth_call given a contract address and calldata or function signature, returning decoded results or revert reasons.
Price / call$0.003
Success—
StatusUnknown
How this service works
Call when an agent needs a read-only Ethereum eth_call. Send to and data (hex) or a function signature plus args. Optional from and block. Reverts return a decoded reason. No state change and no spend. Send JSON {"to":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","data":"0x18160ddd"}. Exact $0.003 USDC on Base. Try unpaid POST /v1/sandbox/eth-call first.
Output
Returns the decoded output of the eth_call — such as a uint256 balance, a string name, or a boolean — along with a decoded revert reason if the call reverted. No transaction is broadcast and no ETH or gas is spent.
Example use cases
Query ERC-20 token total supply
“What is the total supply of USDC? Call the totalSupply() function on the USDC contract at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum mainnet.”
Check wallet token balance on-chain
“How many USDC tokens does the address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 hold? Use balanceOf(address) on the USDC contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48.”
Read DeFi protocol state variable
“Can you read the decimals() value from the DAI stablecoin contract at 0x6B175474E89094C44Da98b954EedeAC495271d0F on Ethereum mainnet?”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/eth-call?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to read on-chain Ethereum mainnet state from a smart contract without sending a transaction or spending gas. Prefer it over web3 library calls when running in an environment without direct Ethereum node access. It supports both raw calldata hex and human-readable function signatures with typed arguments, and it decodes revert reasons automatically. Try the free sandbox endpoint at /v1/sandbox/eth-call first to validate your call before paying.
Side effects
- Contract does not exist at the given address — returns an error or empty result
- Calldata is malformed or signature is invalid — returns a parse or revert error
- Both data and signature provided simultaneously — returns a validation error
- Block tag is invalid or not yet available — returns an error
- Contract call reverts — returns a decoded revert reason string
- Network timeout or Ethereum node unavailability — returns a 5xx error
- Payment not received (x402) — returns 402 Payment Required before processing
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| to | string | Contract to call on Ethereum mainnet. Example: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48. The call is eth_call with no value, so it cannot change state. |
| args | string | JSON array of arguments. Example: ["0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"]. A POST array is accepted. Requires signature. |
| data | string | Calldata, 0x hex, at most 2048 characters. Example: 0x18160ddd (totalSupply()). Send data or signature, not both. eth_call cannot change state. |
| from | string | Optional eth_call from address. Example: 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045. It is not a transaction sender and nothing is spent. |
| block | string | Block tag. Example: latest. Also finalized, safe, or a block number. Default latest. |
| signature | string | Function signature. Example: decimals() or balanceOf(address)(uint256). args is a JSON array when the function has parameters. Send signature or data, not both. |
Tags
x402
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