Neb. Rev. Stat. § 13-1503

Any one or more public agencies may enter into an agreement with any one or more tribal governments to perform any administrative service, activity, or undertaking that any of the public agencies or tribal governments entering into the contract is authorized by law to perform. The agreement shall be authorized and approved by the governing body of each party to the agreement. The agreement shall fully set forth the powers, rights, obligations, and responsibilities of the parties to the agreement.