# CCIP v2.0.0 IRMN API Reference
Source: https://docs.chain.link/ccip/evm/api-reference/v2.0.0/i-rmn

> For the complete documentation index, see [llms.txt](/llms.txt).

## Summary

`IRMN` defines the minimal on-chain interface for interacting with the Risk Management Network (RMN).

It allows CCIP contracts to:

- Check whether a Merkle root is blessed.
- Check whether the system is globally cursed.
- Check whether a specific subject is cursed.

All functions are read-only.

***

## Contract

`chains/evm/contracts/interfaces/IRMN.sol`

***

## Import

```solidity
import {IRMN} from "chainlink-ccip/chains/evm/contracts/interfaces/IRMN.sol";
```

***

## Interface surface

```solidity id="t8k2dp"
interface IRMN {
```

***

### Struct: TaggedRoot

```solidity id="q9l6vf"
struct TaggedRoot {
  address commitStore;
  bytes32 root;
}
```

Represents a Merkle root tagged with the address of the commit store contract.

***

### isBlessed

```solidity id="b2j5xn"
function isBlessed(
  TaggedRoot calldata taggedRoot
) external view returns (bool);
```

Returns whether the specified tagged root is currently blessed.

***

### isCursed()

```solidity id="m4c9rs"
function isCursed() external view returns (bool);
```

Returns `true` if a global or legacy curse is active.

***

### isCursed(bytes16)

```solidity id="u7p3lx"
function isCursed(
  bytes16 subject
) external view returns (bool);
```

Returns `true` if:

- A global curse is active, or
- The specified subject is cursed.

***

```solidity id="f1k6zw"
}
```

***

## Integration notes / expectations

- `isBlessed` results may change over time and must not be cached across transactions.
- Curse checks should be performed immediately before executing sensitive operations.
- Subjects (e.g., chain selectors) may be encoded as `bytes16(uint128(chainSelector))` by calling contracts.

***

## Related Interfaces & Contracts

- [`IRMNRemote`](/ccip/evm/api-reference/v2.0.0/i-rmn-remote)
- [`RMNRemote`](/ccip/evm/api-reference/v2.0.0/rmn-remote)
- [`OffRamp`](/ccip/evm/api-reference/v2.0.0/offramp)
- [`OnRamp`](/ccip/evm/api-reference/v2.0.0/onramp)