What you actually need, stage by stage.
Pre-seed: two or three people and an idea
Start with a founders’ agreement. This is the single most skipped document at this stage, and the one that causes the most damage later if it’s missing when a co-founder relationship goes wrong.
Seed: bringing in outside money
A term sheet sets the terms, then a SAFE, convertible note, or full share subscription formalises the investment, alongside a shareholders’ agreement that protects both you and your new investors.
Building the team: your first real hires
An ESOP pool and proper IP assignment from every employee and contractor, so the company, not any individual, owns what gets built.
Series A and beyond
More formal investor rights agreements, updated shareholders’ terms, and governance that scales with a growing board and cap table.