Ala. Code § 11-50A-26
The provisions of any bond resolution, trust agreement or indenture authorized in this chapter shall be a contract with every holder of the bonds, bond anticipation notes or notes; and the duties of the authority under this chapter and under any bond resolution, indenture, or trust agreement shall be enforceable by any bondholder or noteholder by mandamus or other appropriate action. While any of the bonds, bond anticipation notes or notes issued by the authority shall remain outstanding, the powers, duties, or existence of the authority or of its officers, employees, or agents shall not be diminished, impaired, or affected in any manner which will affect adversely the interest and rights of the holders of those bonds, bond anticipation notes or notes. Any change in name or composition of the authority shall in no way affect the vested rights of any person under the provisions of this chapter or impair the obligations of any contracts existing under this chapter. The provisions of this chapter shall be for the benefit of the state, the authority and every owner of the authority's bonds, bond anticipation notes and notes and, upon and after the issuance of bonds, bond anticipation notes or notes under the provisions of this chapter, shall constitute an irrevocable contract by the state with the owners of such bonds, bond anticipation notes and notes.
Ala. Code § 11-50A-26 (1975)