Mass. Gen. Laws ch. 209B, § 11 – Custody proceedings in foreign courts; evidentiary hearings within state; transfer of information; orders to appear in foreign court; expenses

(a) Upon request of the court of another state the courts of the commonwealth which are competent to hear custody matters may order a person in the commonwealth to appear at a hearing to adduce evidence or to produce or give evidence under other procedures available in the commonwealth or may order investigations to be made for use in a custody proceeding in another state. A certified copy of the transcript of the record of the hearing or the evidence otherwise adduced and of any investigation shall be forwarded by the clerk or register of the court to the requesting court.
(b) Upon request of the court of another state a competent court of the commonwealth may order a person in the commonwealth to appear alone or with the child in a custody proceeding in another state. The court may condition compliance with the request upon assurance by the other state that travel and other necessary expenses will be advanced or reimbursed.
Notwithstanding any provision of this chapter to the contrary, no child shall be ordered or compelled to appear or attend such proceeding in another state when, after a hearing a judge makes a finding that there is probable cause to believe that such child may be placed in jeopardy or exposed to risk of mental or physical harm by such return to said other state.