Texas Family Code - FAM § 157.375. Immunity to Civil Process

(a) While in this state for the sole purpose of compelling the return of a child through a habeas corpus proceeding, the relator is not amenable to civil process and is not subject to the jurisdiction of any civil court except the court in which the writ is pending. The relator is subject to process and jurisdiction in that court only for the purpose of prosecuting the writ.

(b) A request by the relator for costs, attorney's fees, and necessary travel and other expenses under Chapter 106 or 152 is not a waiver of immunity to civil process.