The code contains sections codifying that justices should not allow outside relationships to influence their official conduct or judgment, placing restrictions on justices participating in fundraising and reiterating limits on the accepting of gifts. It also states that justices should not “to any substantial degree” use their judicial resources or staff to engage in non-official activities.
Note that it sounds like this has NOT been officially adopted yet and so far there is no obvious means of enforcement.
See also: https://www.nytimes.com/2023/11/13/us/politics/supreme-court-ethics-code.html
Edit: Politco has posted the PDF of the “CODE OF CONDUCT FOR JUSTICES OF THE SUPREME COURT OF THE UNITED STATES”
More to the point, there are some perfectly suitable rules that every other federal judge is bound to, we don’t need a new set of rules at all.