Does Kliently support witnesses on a contract?

Contracts & e-sign

Yes — witnesses are supported alongside the main signers. Where an engagement calls for a witness, you can include them in the signing flow so their signature is captured on the same document.

Like every other party, a witness gets their own unique link and their action is recorded in the audit trail. Whether a witness is needed depends on your jurisdiction and the type of agreement, so check what your situation requires.