New York Consolidated Laws, Partnership Law - PTR § 121-110. The partnership agreement

(a) The partnership agreement shall be signed by all general partners, in person or by attorneys in fact, and may, but need not, be signed by the limited partners.

(b) A limited partnership shall have a written partnership agreement.  Except as provided in sections 121-702 and 121-705 of this article, no person shall have any rights, or be subject to the liabilities, of a general partner who has not signed the partnership agreement in person or by attorney in fact.

(c) The partnership agreement of a limited partnership may be amended from time to time as provided therein;  provided, however, that, except as may be provided otherwise in the partnership agreement, without the written consent of each partner adversely affected thereby, no amendment of the partnership agreement shall be made which (i) increases the obligations of any limited partner to make contributions, (ii) alters the allocation for tax purposes of any items of income, gain, loss, deduction or credit, (iii) alters the manner of computing the distributions of any partner, (iv) alters, except as provided in subdivision (a) of section 121-302 of this article, the voting or other rights of any limited partner, (v) allows the obligation of a partner to make a contribution to be compromised by consent of fewer than all partners or (vi) alters the procedures for amendment of the partnership agreement.