# Straelo Relay Chain Contract Call

> Straelo Relay Chain Contract Call is a paid API for AI agents from relay.straelo.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-11).

Executes a read call against an EVM smart contract on Ethereum or Base by submitting hex-encoded calldata and returning the raw on-chain result.

## Facts

- Endpoint: POST https://relay.straelo.com/chain-contract-call?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/straelo-relay-chain-contract-call-bd95e068
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Qry1p2y_ZNwEvh4YUS1OG

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 straelo-relay-chain-contract-call-bd95e068 -d '<json body>'
```

Example prompt: Call the balanceOf function on the USDC contract at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum — here's the hex calldata: 0x70a08231000000000000000000000000abcdefabcdefabcdefabcdefabcdefabcdefabcd

## When to prefer this

Use this endpoint when an AI agent needs to query on-chain state from an Ethereum or Base smart contract without running a local node or managing RPC keys. It is ideal for reading contract data (balances, ownership, pool state) via pre-encoded EVM calldata. Prefer this over general-purpose RPC providers when you need a pay-per-call x402-compatible API with no API key setup, especially in agentic pipelines that already handle USDC micropayments.

## Known failure modes

- Invalid hex calldata returns a parse or execution error
- Contract address not deployed on the specified chain returns an empty result or revert
- Unsupported chain value (anything other than 'ethereum' or 'base') returns a validation error
- Network congestion or RPC downtime may cause elevated latency or timeout
- Malformed contract_address (non-checksummed or invalid length) may cause a rejection

## How this service works

Execute a read-only EVM smart contract call on Ethereum or Base and return the normalized result without managing an RPC provider.

## Output

A JSON object containing the raw hex result of the contract call, the chain queried, the contract address called, the provider name, and the round-trip latency in milliseconds. The result field holds the ABI-encoded return value which must be decoded by the caller.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "type": "string",
   "description": "Read-only hexadecimal ABI calldata."
  },
  "chain": {
   "enum": [
    "ethereum",
    "base"
   ],
   "type": "string",
   "description": "EVM network for the read-only call."
  },
  "contract_address": {
   "type": "string",
   "description": "Target EVM contract address."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "result": "0x",
  "provider": "aex402",
  "latency_ms": 20,
  "contract_address": "0x0000000000000000000000000000000000000000"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/straelo-relay-chain-contract-call-bd95e068/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from relay.straelo.com](https://www.zero.xyz/host/relay.straelo.com/llms.txt)