Predeploys

Predeploys are real accounts with real bytecode, present from genesis at fixed addresses. They differ from precompiles, which are implemented natively by the client and have no code.

Developer-facing

Address	Contract	Purpose
`0x4e59b44847b379578588920cA78FbF26c0B4956C`	CREATE2 factory	The EIP-7997 deterministic deployment proxy. Counterfactual account addresses are defined against it, and any CREATE2 deployment pattern works without deploying a factory first.
`0xca11bde05977b3631167028862be2a173976ca11`	Multicall3	The standard batch-read contract, at its canonical address. Works with every library that expects it.

Both are at the same addresses they occupy on other EVM chains, so tooling that hardcodes them works unmodified.

EIP-8141 infrastructure

Address	Name	Purpose
`0x…00aa`	Frame entry point	The caller that frame execution presents to an account. Account contracts dispatch on `CALLER == 0x…aa` to distinguish a frame invocation from an ordinary call.
`0x…8141`	Frame expiry verifier	A canonical VERIFY-frame target that enforces a deadline. Its `data` is exactly 8 bytes — a big-endian expiry timestamp — and it reverts once that time has passed. At most one such frame per transaction, with zero flags and zero value.

The expiry verifier is a small, general facility: it gives any account a way to make a signed transaction stop being valid after a deadline, without the account having to implement time logic itself.

Full addresses: 0x00000000000000000000000000000000000000aa and 0x0000000000000000000000000000000000008141.

Ethereum system contracts

Present at their standard addresses, as required by the forks Frost activates at genesis.

Address	Contract	EIP
`0x000F3df6D732807Ef1319fB7B8bB8522d0Beac02`	Beacon roots	EIP-4788
`0x0000F90827F1C53a10cb7A02335B175320002935`	History storage	EIP-2935
`0x00000961Ef480Eb55e80D19ad83579A64c007002`	Withdrawal queue	EIP-7002
`0x0000BBdDc7CE488642fb579F8B00f3a590007251`	Consolidation queue	EIP-7251

System address

0xfffffffffffffffffffffffffffffffffffffffe is the caller the protocol itself uses to invoke system contracts at block boundaries. It is not an account you can control or send from.

Checking a predeploy

curl -s https://rpc.frostfi.net -H 'content-type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"eth_getCode",
           "params":["0x4e59b44847b379578588920cA78FbF26c0B4956C","latest"]}'

A non-empty result confirms the contract is live.