Ethereum (EVM)

This page provides examples of policies governing Ethereum (EVM) signing.

Note: see the language section for more details.

Allow ABI-specific contract call parameters

For contract interactions, use Smart Contract Interfaces (ABI upload) rather than raw calldata slicing. ABI-based policies use named arguments (eth.tx.contract_call_args['arg_name']) instead of byte offsets — they’re more readable, less error-prone, and won’t silently break if the contract encoding changes. Raw eth.tx.data[...] slicing is a fallback for contracts where no ABI is available.

Restrict a transfer call to a maximum amount and a specific recipient:

{
  "policyName": "Limit WETH transfers",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.tx.contract_call_args['wad'] < 1000000000000000000 && eth.tx.contract_call_args['dst'] == '0x08d2b0a37F869FF76BACB5Bab3278E26ab7067B7'"
}

Restrict by function name or selector (also requires an ABI upload):

{
  "policyName": "Allow only transfer calls to a contract",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.tx.to == '<CONTRACT_ADDRESS>' && eth.tx.function_name == 'transfer'"
}

See Smart Contract Interfaces for the full upload walkthrough and Solana IDL support.

Allow ERC-20 transfers for a specific token smart contract (raw calldata fallback)

Use this pattern only when an ABI is unavailable. The selector 0xa9059cbb is the 4-byte keccak256 hash of transfer(address,uint256).

{
  "policyName": "Enable ERC-20 transfers for <CONTRACT_ADDRESS>",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.tx.to == '<CONTRACT_ADDRESS>' && eth.tx.data[0..10] == '0xa9059cbb'"
}

Allow anyone to sign transactions for testnet (Sepolia)

{
  "policyName": "Allow signing ethereum sepolia transactions",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.tx.chain_id == 11155111"
}

Allow ETH transactions with a specific nonce range

{
  "policyName": "Allow signing Ethereum transactions with an early nonce",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.tx.nonce <= 3"
}

Allow signing of EIP-712 payloads for Hyperliquid ApproveAgent operations

{
  "policyName": "Allow signing of EIP-712 Payloads for Hyperliquid `ApproveAgent` operations",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.eip_712.domain.name == 'HyperliquidSignTransaction' && eth.eip_712.primary_type == 'HyperliquidTransaction:ApproveAgent' && activity.type == 'ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2'"
}

Inspect nested fields in EIP-712 message payloads

The eth.eip_712.message map supports nested field access using bracket notation, allowing policies to inspect typed data contents beyond just the domain and primary type.

Syntax:

• Nested struct fields: eth.eip_712.message['outerField']['innerField']
• Array element fields: eth.eip_712.message['arrayField'][0]['innerField']

Example: Restrict Hyperliquid orders to a specific asset

Hyperliquid’s HyperliquidTransaction:Order message contains an orders array of Order structs. Each Order uses short field names: a (asset index), b (isBuy), p (price), s (size), r (reduceOnly).

{
  "primaryType": "HyperliquidTransaction:Order",
  "domain": { "name": "HyperliquidSignTransaction", ... },
  "message": {
    "orders": [
      { "a": 3, "b": true, "p": "1800.0", "s": "0.1", "r": false, ... }
    ],
    "grouping": "normalTpsl"
  }
}

To allow only orders for a specific asset (e.g. ETH = asset index 3):

{
  "policyName": "Allow Hyperliquid orders for ETH only",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.eip_712.domain.name == 'HyperliquidSignTransaction' && eth.eip_712.primary_type == 'HyperliquidTransaction:Order' && eth.eip_712.message['orders'][0]['a'] == '3' && activity.type == 'ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2'"
}

Array access is index-based ([0], [1], etc.). The condition message['orders'][0]['a'] == '3' only checks the first order — any additional orders in the array are not evaluated. To restrict all orders in a known-size batch, add a condition for each index: message['orders'][0]['a'] == '3' && message['orders'][1]['a'] == '3'.

Deny signing of NO_OP keccak256 payloads

{
  "policyName": "Deny NO_OP hash signing",
  "effect": "EFFECT_DENY",
  "condition": "activity.type == 'ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2' && activity.params.hash_function == 'HASH_FUNCTION_NO_OP' && activity.params.encoding != 'PAYLOAD_ENCODING_EIP712'"
}

Allow signing of EIP-712 payloads for EIP-3009 transfers

{
  "policyName": "Allow signing of EIP-712 payloads for EIP-3009 Transfers for USD Coin",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.eip_712.domain.name == 'USD Coin' && eth.eip_712.primary_type == 'TransferWithAuthorization' && activity.type == 'ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2'"
}

Allow signing of EIP-712 payloads for EIP-2612 permits for USD Coin

{
  "policyName": "Allow signing of EIP-712 payloads for EIP-2612 Permits for USD Coin",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.eip_712.domain.name == 'USD Coin' && eth.eip_712.primary_type == 'Permit' && activity.type == 'ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2'"
}

Allow signing of EIP-7702 authorizations

{
  "policyName": "Allow signing of EIP-7702 Authorizations",
  "effect": "EFFECT_ALLOW",
  "condition": "eth.eip_7702_authorization.address == '<ADDRESS>' && eth.eip_7702_authorization.chain_id == '<CHAIN_ID>' && eth.eip_7702_authorization.nonce == '<NONCE>' && activity.type == 'ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2'"
}