New York Laws
Part 2 - Form, Formation and Readjustment of Contract
2-210 - Delegation of Performance; Assignment of Rights.

(1) A party may perform his duty through a delegate unless otherwise
agreed or unless the other party has a substantial interest in having
his original promisor perform or control the acts required by the
contract. No delegation of performance relieves the party delegating of
any duty to perform or any liability for breach.
(2) Except as otherwise provided in Section 9--406, unless otherwise
agreed, all rights of either seller or buyer can be assigned except
where the assignment would materially change the duty of the other
party, or increase materially the burden or risk imposed on him by his
contract, or impair materially his chance of obtaining return
performance. A right to damages for breach of the whole contract or a
right arising out of the assignor's due performance of his entire
obligation can be assigned despite agreement otherwise.
(3) Unless the circumstances indicate the contrary a prohibition of
assignment of "the contract" is to be construed as barring only the
delegation to the assignee of the assignor's performance.
(4) An assignment of "the contract" or of "all my rights under the
contract" or an assignment in similar general terms is an assignment of
rights and unless the language or the circumstances (as in an assignment
for security) indicate the contrary, it is a delegation of performance
of the duties of the assignor and its acceptance by the assignee
constitutes a promise by him to perform those duties. This promise is
enforceable by either the assignor or the other party to the original
contract.
(5) The other party may treat any assignment which delegates
performance as creating reasonable grounds for insecurity and may
without prejudice to his rights against the assignor demand assurances
from the assignee (Section 2--609).