It is not necessary to decide whether either of the defendant’s letters to the plaintiff of April 11,1973, constituted a letter of credit within the scope of G. L. c. 106, § 5-102, or as defined in G. L. c. 106, § 5-103. See generally Moss v. Old Colony Trust Co., 246 Mass. 139, 151-152 (1923). On the subsidiary facts found by the master, the plaintiff was entitled to recover by reason of its full performance (and thus its acceptance) of the offer for a unilateral contract (Northampton Inst. for Sav. v. Putnam, 313 Mass. 1, 7 [1943]) set out in the second sentence of the second paragraph of both letters. Lent v. Padelford, 10 Mass. 230, 237-238 (1813). Train v. Gold, 5 Pick. 380, 384-385 (1828). Paige v. Parker, 8 Gray 211, 213 (1857). Bishop v. Eaton, 161 Mass. 496, 499-500 (1894).

Judgment affirmed.