The SAFE — the open standard for startup fundraising | Y Combinator

The open-source, simple agreement that lets investors fund your startup now for shares of stock later. Created at Y Combinator by Carolynn Levy in 2013 and used to raise over $15B+ for YC portfolio companies.
A SAFE (Simple Agreement for Future Equity) is a short contract an investor signs to fund your startup now in exchange for the right to shares of stock in your startup later. It converts into shares automatically when your startup raises a priced round.
"Send a SAFE" is the official tool by Y Combinator for sending SAFEs. It is the fastest way to generate, sign, and send a SAFE — in about two minutes.
Use this prompt with your agent to create and manage your SAFEs. The prompt will install YC CLI, log you in, and walk you through the commands.
The biggest advantage of the post-money SAFE is that the amount of ownership sold is immediately transparent and calculable for both the founder and the investor. Start from how much you're targeting and how much ownership you're willing to sell — the valuation cap follows from the two.
Say you're targeting a $1M raise and 15% ownership sold. Your post-money valuation cap is $1M ÷ 15% = ~$6.7M, or "I'm targeting $1M at $6.7M post / $5.7M pre." Raise less on that cap and you sell less: $500k is ~7.5%, $800k is ~12%. You can also raise on more than one cap — $500k at a $5.5M cap (~9%) plus $500k at an $8.3M cap (~6%) gets you to the same ~15% sold.
Run your own numbers in the SAFE calculator.
The handful of terms worth knowing before you raise on a SAFE.
Not sure which instrument best fits your fundraise? See how the three compare on cost, speed, and control.
Three versions of the post-money SAFE for US companies, plus an optional side letter.
Valuation Cap versions for companies formed in Canada, the Cayman Islands, and Singapore, each with an optional side letter. Consult a lawyer licensed in the relevant country before using these.
Read the SAFE User Guide for sample conversion math, an explanation of the pro rata side letter, and best practices.
The instrument itself — what a SAFE is, how it converts, and the terms behind it.
The tool itself — how to generate, sign, and send a SAFE to any investor.
Needless to say, YC does not assume responsibility for the contents of, or the consequence of using, the Send a SAFE tool or any version of the SAFE found on our website. Before using the Send a SAFE tool or any of the SAFE forms, you should consult with a lawyer licensed in the country where your company was formed.
The official tool that lets you generate, send, and sign a SAFE in two minutes.
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