Founders & Small BusinessFree
Y Combinator Application Writer and Editor
Paste your notes, a draft or your deck. Get every application answer written plainly from your facts, with gaps marked and the filler cut.
River drafts your Y Combinator application from what you already have: notes, a deck, an old draft or a page of numbers. It checks the current questions on YC's site, then writes each answer plainly in your own voice, cut to the length the form allows. Anything an answer needs that you did not give, such as a founder story or a date, is marked for you to fill in rather than made up. You get the whole application in one document you can edit and paste across.
YC partners have said publicly that applications have grown about 60 percent longer in three years, and that machine-written answers are easy to spot. So this writer does the opposite of most generators: it shortens every answer, strips out the buzzwords and stock phrases, and refuses to invent traction, credentials or stories. It follows YC's own advice to put the answer in the first sentence and to be specific and matter-of-fact.
It is for founders applying for the first time, founders reapplying with new progress, and anyone with a draft that has grown too long. Start a few weeks before the deadline so you have time to gather the facts it marks. Once you are through, the pitch deck writer turns the same facts into a seed deck, and the SAFE and note conversion model shows what a deal would do to your ownership.
What YC partners look for in an application
YC's own advice on applying is blunt: give the answer in the first sentence, in the simplest possible terms, and be as specific and matter-of-fact as you can. Every unnecessary word subtracts from the necessary ones. The question about what your company is going to make is answered well by a sentence a stranger could repeat, not by a vision statement. Describing yourself as a variant of something familiar is fine when the comparison is accurate.
Compare two illustrative answers to how far along you are. The first: 'We have seen strong early traction and growing demand from clinics.' The second: 'Launched in May. 41 clinics pay us $500 a month, up from 9 in June. Two signed annual contracts last week.' The second is shorter, can be checked, and invites a good interview question. The same rule applies to competitors: naming them shows you know the market, while claiming none suggests you have not looked.
A few answers can only come from you. The questions about the most impressive thing each founder has built, and about a time you hacked a non-computer system to your advantage, need real stories, so River marks them with a prompt instead of inventing one. YC's FAQ says about 40 percent of companies in a batch are just an idea, and that progress since a previous application is a strong signal. Its advice page adds that founders who submit a video are statistically much more likely to be interviewed.
How it works
Share your material
Paste notes or an old draft, drop your deck, and say whether you have applied before.
River checks the form
It looks up the current questions and deadline on YC's site before drafting a single answer.
Get every answer
Each question with a plain, specific answer from your facts, and gaps marked for you to fill.
Tighten and practise
Ask River in chat to cut answers further or run a mock interview based on your application.
What you get
- Every application answer drafted from your facts, under the question's current wording from YC's site
- Answers cut to the length limits, with the point in the first sentence as YC advises
- Buzzwords, filler and machine-sounding phrasing removed, so each answer reads in your own plain voice
- Founder stories and missing facts marked for you to write, never invented to fill the form
- An outline for the one-minute founder video, with what each founder should cover on camera
- The three weakest answers named in chat, with the fact that would make each one stronger
Common questions
Will YC be able to tell I used River?
YC partners have said they notice machine-written answers: longer, glossier and oddly alike. That is why River writes short, plain answers only from facts you give, and leaves personal stories to you. Read every answer aloud and change anything that does not sound like you. The application should be yours; River does the cutting and checking.
Which questions does it answer?
All the written questions on the current form, which River checks on YC's site before drafting, plus an outline for the founder video. YC changes the form between batches, so the document uses the wording River finds. If it cannot confirm the current version, it says so, and you should check the wording in the application portal.
What if we have no users yet?
Say so plainly and show what you do have: how many potential customers you have spoken to, what they told you, what you have built and how fast. YC's FAQ says about 40 percent of the companies it funds in a batch are just an idea. A clear, honest progress answer reads far better than vague claims of strong interest.
Can it edit the draft I already wrote?
Yes. Paste or attach it, and River keeps the substance and voice of your answers while cutting them to the point, checking each against its length limit, and marking claims that need a number or a date. In chat it lists what it cut, so you can put back anything that mattered.
We applied before and were rejected. What should change?
Pick that you applied before. YC's FAQ says about half the companies in a typical batch applied more than once, and that progress since the last application is a strong signal. River builds your answers around concrete progress, such as users, revenue, launches or a founder going full time, and keeps the rest consistent with it.
Does it work for other accelerators?
Mostly, yes. Other accelerators ask overlapping questions about the team, product, progress and market. After the YC draft, paste another program's questions into the chat and River reuses the same facts in their wording and limits. Check that program's own site for its current questions and deadline. If you are also raising from angels or funds, the investor target list template dates each fund's last cheque at your size.
Sources
Built by
Chandler Supple
Co-founder & CEO, River
Chandler has spent the last six years working in AI, building tools for millions of users and Fortune 100 companies. In 2025, he co-founded River to build a new kind of operating system for AI agents.
Y Combinator Application Writer and Editor
Describe what you need, add any files you have, and your workspace opens with the work already underway.