How to Detect EIP-7702 Support with a Single RPC Call

Oct 15, 2025

Quick test to check if any Ethereum network supports EIP-7702 account abstraction.

The Problem

With EIP-7702 rolling out (enabled on Ethereum mainnet via Pectra upgrade), you need to know which networks support it before building. Traditional methods require complex setup or waiting for official announcements.

The Solution

Use eth_estimateGas with state override to probe for EIP-7702 support:

curl https://your-rpc-endpoint.com \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_estimateGas",
    "params": [
      {
        "from": "0xdeadbeef00000000000000000000000000000000",
        "to": "0xdeadbeef00000000000000000000000000000000",
        "data": "0x00",
        "value": "0x0"
      },
      "latest",
      {
        "0xdeadbeef00000000000000000000000000000000": {
          "code": "0xef01000000000000000000000000000000000000000001"
        }
      }
    ],
    "id": 1
  }'

How It Works

State override temporarily sets code 0xef01...0001 for a dummy address
0xef01 prefix is EIP-7702's magic delegation designator
Unsupported nodes reject 0xef as invalid opcode
Supported nodes recognize delegation and return gas estimate

Reading Results

✅ Supported

{
  "jsonrpc": "2.0",
  "result": "0x5875"
}

❌ Not Supported

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32000,
    "message": "invalid opcode: opcode 0xef not defined"
  }
}

Why This Works

0xef01: EIP-7702 delegation designator format
Target 0x01: ecrecover precompile (exists on all EVM chains)
From = To: Simulates EOA calling itself (core EIP-7702 pattern)
State override: Tests without actual deployment

Verified Networks

✅ Ethereum Mainnet (Pectra upgrade)
✅ BNB Chain Mainnet
✅ Polygon PoS (Bhilai hardfork)
❌ opBNB Mainnet (invalid opcode: opcode 0xef not defined @2025.10.15)
❌ Linea ( invalid opcode: opcode 0xef not defined @2025.10.15)

Related: EIP-7702, Account Abstraction, Smart EOAs, Ethereum Pectra Upgrade, State Override Testing