Okla. Stat. tit. 12, § 12-689
Judgment by confession
Any person indebted, or against whom a cause of action exists,
may personally appear in a court of competent jurisdiction, and,
with the assent of the creditor or person having such cause of
action, confess judgment therefor; whereupon judgment shall be
entered accordingly.
R.L. 1910, § 5131.