The most valuable document a new company signs is the one governing the relationship among the people who started it.
Vesting on founder equity. Time-based over a period with a cliff, so that a founder who leaves early does not retain a full stake. Repurchase rights at cost for unvested shares, and consideration of whether vested shares are repurchasable on a bad leaver event.
Acceleration. Single or double trigger on a change of control, and treatment on termination without cause.
Intellectual property assignment in present-tense language, covering everything created before formation and relating to the business, with a schedule of prior inventions excluded.
Roles and decisions. Who decides what, and what requires unanimity. Most founder disputes are about decision rights rather than about equity.
Departure. What happens to the leaver’s shares, their board seat, their guarantee obligations and their access to information.
Compensation and expense. How founders are paid, and how expenses are approved, before there is a finance function.
Deadlock. A mechanism, because two founders holding equal stakes is the default arrangement and the default failure mode.
Confidentiality and non-solicitation appropriate to the jurisdiction.