# agent402.tools Ethereum JSON-RPC Passthrough

> agent402.tools Ethereum JSON-RPC Passthrough is a paid API for AI agents from agent402.tools, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Forwards arbitrary read-only JSON-RPC method calls to EVM-compatible blockchain networks via a whitelisted set of safe, non-mutating methods

## Facts

- Endpoint: POST https://agent402.tools/api/eth-call
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-tools-ethereum-json-rpc-passthrough-8647a3d6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rfOBAt7E9M2qonOltVd9c

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 agent402-tools-ethereum-json-rpc-passthrough-8647a3d6 -d '<json body>'
```

Example prompt: Can you call eth_call on Base with params [{'to':'0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913','data':'0x18160ddd'},[]] so I can read the total supply of that contract?

## When to prefer this

Use this endpoint when you need to make arbitrary read-only JSON-RPC calls to EVM chains (Ethereum, Base, Polygon, Arbitrum, Optimism) without managing your own RPC node or API key. Ideal for power-user scenarios where pre-built endpoints don't cover the exact method needed. Prefer this over managed single-purpose endpoints when you need low-level access to eth_call, eth_getLogs, eth_getBlockByNumber, eth_getTransactionReceipt, or eth_blockNumber directly.

## Known failure modes

- Method not in read-only whitelist — endpoint rejects mutating or unsupported methods
- Invalid params array for the chosen method — JSON-RPC error returned
- Unsupported network name — defaults to Base or returns an error
- Malformed JSON body — 400 bad request
- Network congestion or node unavailability — upstream RPC timeout or 503
- Payment not completed via x402 protocol — 402 Payment Required

## How this service works

Escape hatch for power users: forward an arbitrary read-only JSON-RPC method to the chain. Method must be in our read-only whitelist (eth_call, eth_getLogs, eth_getBlockByNumber, eth_getTransactionReceipt, eth_chainId, eth_blockNumber, etc.). Mutating methods (eth_sendTransaction, eth_sendRawTransaction) are rejected - sign and broadcast through your own provider.

## Output

Returns the JSON-RPC response object for the requested read-only method, including the result field (e.g. hex-encoded return value for eth_call, block object for eth_getBlockByNumber, array of log objects for eth_getLogs, or a hex block number for eth_blockNumber)

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "method": {
   "type": "string",
   "description": "JSON-RPC method (must be in the read-only whitelist)."
  },
  "params": {
   "type": "array",
   "description": "JSON-RPC parameter array (often empty for simple methods)."
  },
  "network": {
   "type": "string",
   "description": "ethereum / base / polygon / arbitrum / optimism (default base)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "method": "eth_blockNumber",
  "result": "0x1234567",
  "network": "base"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-ethereum-json-rpc-passthrough-8647a3d6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)