# EVM Contract Call Simulator (eth_call with Revert Decoding)

> EVM Contract Call Simulator (eth_call with Revert Decoding) is a paid API for AI agents from agent.connskill.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Executes a read-only EVM smart contract call (eth_call) on supported chains, returning the decoded result, revert reason, and optional gas estimate — without broadcasting a transaction.

## Facts

- Endpoint: POST https://agent.connskill.com/chain/v1/chain-call
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-contract-call-simulator-eth-call-with-revert-decoding-e4c2883f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yJXd7GezvUHed01oetuvF

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability evm-contract-call-simulator-eth-call-with-revert-decoding-e4c2883f -d '<json body>'
```

Example prompt: Can you simulate calling the balanceOf function on the USDC contract at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum for wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 — use the latest block and also give me the gas estimate?

## When to prefer this

Choose this endpoint when you need to read on-chain EVM contract state or simulate a transaction before signing, especially when you want decoded revert reasons rather than raw hex errors. It supports 5 major EVM chains (Base, Ethereum, Arbitrum, Optimism, Polygon) and includes optional gas estimation in a single call. Prefer it over raw RPC calls when you need human-readable revert decoding and a clean JSON response without managing your own RPC provider.

## Known failure modes

- Invalid or non-existent contract address returns reverted: true with an error message
- Malformed ABI-encoded calldata causes a revert or empty result
- Unsupported chain name returns a validation error
- Block tag referencing a pruned or unavailable block may return an error
- Network timeout or RPC provider unavailability returns a 5xx error
- Missing required fields (chain or to) return a 400-level validation error

## How this service works

Read-only EVM contract call (eth_call) with decoded revert reason and optional gas estimate — simulate before you sign

## Output

Returns a JSON object with: `result` (hex-encoded return data from the call), `status` (success or failure string), and `reverted` (boolean indicating whether the call reverted). When a `from` address is provided, a gas estimate is also included. If the call reverts, the decoded revert reason is surfaced in the response.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "chain",
  "to"
 ],
 "properties": {
  "to": {
   "type": "string",
   "description": "Contract address to call (0x…)"
  },
  "data": {
   "type": "string",
   "description": "ABI-encoded calldata (0x…), e.g. 0x70a08231… for balanceOf"
  },
  "from": {
   "type": "string",
   "description": "Caller address — when set, a gas estimate is included"
  },
  "block": {
   "type": "string",
   "description": "latest (default), safe, finalized, earliest, or hex block number"
  },
  "chain": {
   "type": "string",
   "description": "One of: base, ethereum, arbitrum, optimism, polygon"
  },
  "value": {
   "type": "string",
   "description": "Value in wei (hex or decimal string)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "result": {
   "type": "string"
  },
  "status": {
   "type": "string"
  },
  "reverted": {
   "type": "boolean"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-contract-call-simulator-eth-call-with-revert-decoding-e4c2883f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent.connskill.com](https://www.zero.xyz/host/agent.connskill.com/llms.txt)