computeRegisterPreimage

Computes the 32-byte preimage that an early-exit spend of a lockup must reveal: sha256 of the staker's Clarity consensus serialization. Pure computation: no network call.

---

Usage

import { computeRegisterPreimage } from '@stacks/bitcoin-staking';

const preimage = computeRegisterPreimage('SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7');
// 32 bytes: sha256(to-consensus-buff? staker)

Notes

• The lockup script commits to the staker by the double hash sha256(sha256(to-consensus-buff? staker)) (construct-lockup-script). The OP_ELSE (early-exit) branch checks that the revealed witness item is 32 bytes and hashes to that commitment, so it needs this single-hash value. The OP_IF (locktime) branch does not use it.

• finalizeReclaim calls this for the early-exit path. You need it directly only to assemble the witness yourself.

• Standard and contract principals are both accepted, serialized the same way pox-5 serializes them. Throws if stxAddress does not decode as a Stacks address.

Reference Link

---

Signature

function computeRegisterPreimage(stxAddress: string): Uint8Array;

---

Returns

Uint8Array

The 32-byte preimage.

---

Parameters

stxAddress (required)

• Type: string

The staker's Stacks principal, standard or contract. It must be the principal the lockup script was built for.