You Can Now Send a SAFE in Two Minutes. That Is How Founders Give Up 40% of Their Company Without Noticing.
On August 19, Y Combinator opened the software its own batch companies use to send SAFEs to every founder, for free. YC's page says it takes about two minutes to generate, sign and send one. It is also, in YC's words, "built for agents." The page includes a prompt you can paste into an AI agent that installs YC's command-line tool and lets the agent draft and manage your SAFEs.
That is genuinely useful. The SAFE was invented at YC in 2013 to make early fundraising simpler and cheaper, and it worked: YC says it has been used to raise more than $15 billion for its own companies, and it is now the default instrument for pre-seed money.
It also removes the last bit of friction between a founder and a bad decision. When a round is a stack of individually small checks, each one looks harmless. The cost only shows up later, all at once, when the stack converts.
How a post-money SAFE prices itself
YC's explanation is the clearest one there is. On a post-money SAFE, the ownership you sell equals the investment divided by the valuation cap. If you want to raise $1 million and sell 15%, your cap is $1 million ÷ 15%, about $6.7 million. Raise $500,000 on that cap and you have sold about 7.5%.
You can also raise on more than one cap. YC's example is $500,000 at a $5.5 million cap, about 9%, plus $500,000 at $8.3 million, about 6%, for the same 15% in total.
That transparency is the point of the post-money design, which YC adopted as its standard in 2018. Each SAFE holder knows exactly what percentage they bought. The consequence is that every additional SAFE comes out of the founders' share. One SAFE holder is not diluted by the next one. You are.
A stack that looks small
Here is a hypothetical, simplified pre-seed. It ignores discounts and any existing option pool.
- An angel writes $250,000 on a $5 million cap. That is 5%.
- Three months later, a small fund writes $500,000 at $8 million. That is 6.25%.
- After a good quarter, another $750,000 comes in at $12 million. That is 6.25%.
Each conversation felt like a small number. The founders have now sold 17.5% before a single priced round, and own 82.5%.
Then the seed round arrives: $3 million at a $15 million post-money valuation, so the new investors own 20%. The lead also asks for an option pool equal to 10% of the company after the round, created before their money goes in, which is a standard request.
The new money and the new pool together take 30% of the company. Everyone who was already there splits the other 70%. The founders' 82.5% becomes about 58%.
Nobody did anything unusual. There was no bad term in any document. The founders simply sold the company in pieces they never added up, and then took a normal seed round on top. That 58% is close to what typical data shows: a SaaStr summary of Carta's figures put median founding-team ownership at 56.2% after a priced seed round, and 36.1% by Series A.
Why this matters more now
Speed changes behavior. When a SAFE took a lawyer, a few days and a few thousand dollars, founders thought twice about sending a fourth one. When it takes two minutes and an agent can draft it, the natural friction that used to make founders add things up is gone.
YC itself seems aware of this. The prompt on its page tells the agent that "sending a SAFE emails a real investor and cannot be undone," and instructs it never to send one "without first showing me the exact terms and getting my explicit confirmation." That is the right instinct. It is a guardrail for one document, though, not for the total.
The market makes the temptation stronger. Seed capital is concentrating in companies that already have momentum, and as we wrote in 51 Funds Still Writing Early Checks, many first-time founders raise their pre-seed in small pieces from whoever says yes. A rolling SAFE round is the natural shape of that, and it is also the shape most likely to sell more than you meant to.
Rules for a pre-seed raised on SAFEs
Set a dilution budget before the first conversation. Decide the total percentage you are willing to sell before your priced round, and write it down. Every SAFE spends from that budget. When it is gone, the round is over, even if someone else wants in.
Keep one cap table model and update it before you sign, not after. It should show what founders own today, after every SAFE converts, and after a plausible seed round with a pool top-up. If an investor's check changes the bottom line by more than you expected, you see it before the money arrives.
Close low-cap SAFEs before you issue an uncapped MFN. YC's own guidance is specific here. An MFN SAFE takes the best terms of any SAFE you issue later, and the date that counts is the later of signing or the wire arriving. Get the lower-cap money fully wired first.
Watch the side letters. Pro rata rights live in a separate side letter. Each one is reasonable on its own. Together they can take a large part of your next round before your lead investor has bought anything.
Let the agent draft. Do the arithmetic yourself. An agent is excellent at producing documents correctly and quickly. Deciding how much of your company to sell is not a drafting task.
Our free course has a full lesson on this, Funding: From Bootstrapping to Venture, including a worked dilution example and an assignment to build the cap table model before your next raise.
The honest version
Selling part of your company for money is not a failure. Owning 58% of a funded company is usually better than owning all of one that never got going.
The mistake is not raising. It is raising without a total. A SAFE takes two minutes now. Spend twenty on the spreadsheet first.
