Does Vyper have an equivalent CHAINID assembly function?

Question

Since v0.5.12, Solidity provides a CHAINID OPCODE in assembly:

function getChainID() external view returns (uint256) {
    uint256 id;
    assembly {
        id := chainid()
    }
    return id;
}

Is there an equivalent in Vyper?

Answer 1

Since Vyper v0.1.0-beta15 the chain ID is available through the chain.id environment variable:

Here is a minimal example to verify the behavior:

@public
@constant
def foo() -> uint256:
   return chain.id

Note that this is only possible if the compiler is set to target the Istanbul EVM ruleset or later.