Sign an experiment

Records your signature on the experiment. The body must contain the user's password to re-authenticate the signer and prevent accidental signing. On success the experiment status is automatically set to COMPLETED, an audit log entry is written, and (when witness signing is configured) the pre-signer is notified that the experiment was witnessed and approved.

If your group has signature workflows enabled, this endpoint routes the experiment through that workflow instead — see the signature-workflow endpoints for the alternative path.

If your group enforces a witness signature, an existing pre-signature from another user must already be in place; you cannot sign your own pre-signature.

Note: if the experiment is already signed, the call returns 401 (Unauthorized) rather than the more accurate 409 Conflict — handle 401 from this endpoint as a possible already-signed signal, not just an auth failure.