CCIP v2.0.0 RMNProxy API Reference

Summary

RMNProxy is a lightweight forwarding proxy that provides a stable address for Risk Management Network (RMN, historically ARM) integrations.

Instead of storing an RMN implementation address in every dependent contract, integrations reference RMNProxy. The proxy forwards calls to the currently configured RMN implementation.

Key properties:

• Stable integration address
• Owner-controlled implementation updates
• Generic forwarding via fallback
• Uses call (not delegatecall)
• No implementation storage collision risk

Contract

chains/evm/contracts/rmn/RMNProxy.sol

Import

import {RMNProxy} from "chainlink-ccip/chains/evm/contracts/rmn/RMNProxy.sol";

Target + upgrade model

• The proxied implementation address is stored in s_arm.
• The owner may update the implementation via setARM.
• All unknown calls are forwarded using call.
• No delegatecall is used.
• Storage remains in the implementation contract.

Inheritance

• OwnerIsCreator
• ITypeAndVersion

typeAndVersion

string public constant override typeAndVersion =
  "ARMProxy 1.0.0";

State

Constants

string public constant override typeAndVersion =
  "ARMProxy 1.0.0";

Immutables

None declared.

Storage

address private s_arm;

Current RMN implementation address.

Constructor

constructor(address arm)

Behavior:

• Calls setARM(arm).

Reverts:

error ZeroAddressNotAllowed();

If arm == address(0).

External API

setARM

function setARM(address arm)
  public
  onlyOwner

Behavior:

• Reverts ZeroAddressNotAllowed() if arm == address(0).
• Sets s_arm = arm.
• Emits:

event ARMSet(address arm);

getARM

function getARM()
  external
  view
  returns (address);

Returns s_arm.

Fallback

fallback() external payable;

Behavior:

1. Loads arm = s_arm.
2. Reverts if arm has no code (extcodesize == 0).
3. Copies calldata.
4. Executes:

call(gas(), arm, 0, calldataPtr, calldataSize, 0, 0)

5. If call fails:

   • Reverts with returned data.

6. If call succeeds:

   • Returns returned data.

Notes:

• Ether is not forwarded (value = 0).
• Proxy storage is not modified.
• No delegatecall.

Events

event ARMSet(address arm);

Errors

error ZeroAddressNotAllowed();

Security model

• Only owner may update the implementation.
• Zero implementation address is disallowed.
• Calls to non-contract addresses revert.
• No delegatecall: eliminates storage collision risk.
• All RMN state resides in the implementation contract.

Related Interfaces & Contracts

• IRMN
• IRMN
• OwnerIsCreator