yc-outreach, a free Python tool, picks a Y Combinator batch and writes a personalised cold email to each founder

Sending a cold email to every founder in a Y Combinator batch used to be a day of copy and paste. A tool called yc-outreach, published to GitHub on 3 October 2026 under MIT, turns the batch into a loaded list of founders and writes a personalised email to each one from a single template.

The project is on GitHub as adityajha2005/yc-outreach and sat at 87 stars at publication. It uses standard-library Python only, with no package install, and runs locally. The repository ships a plain HTML page as the composer, which the author says deploys straight to Vercel.

What the tool actually does

The flow is three steps. First, pick a batch, which the tool fetches from the Y Combinator Startup Directory and parses into founders and companies. Second, resolve a likely email address for each founder. Third, open the composer with the template filled in for each row, so sending becomes clicking rather than typing.

How the email addresses are produced

This is where the method matters, and the project's own README gives both the mechanism and a number. The tool tries four sources in order: a verified result from the user's own Apify token, an unverified Apify result, an email the company already publishes on its site, and finally a guess from the first and last name against the company domain in common formats such as first@domain, first.last@domain, flast@domain and firstlast@domain.

The author tested the guesser against 151 verified founder emails collected through Apify. His own numbers: "The first guess matched 80%, and the right address was somewhere in the guess list 93% of the time." Those are his figures, and they are measured on one batch rather than on an industry-wide sample.

Neither Apify nor an API key is required to run the tool. Verification is on if the user supplies a token, and off if they do not. Running with verification off means the tool is relying on the guesser, which is where the 80% number applies.

For a team using it

The honest reading is that this is a one-click way to write to a hundred founders in an afternoon. It is not a database. The source is Y Combinator's public directory. The guessing step is well calibrated for domains that follow the common patterns and is wrong for the rest, which means a sent batch will still bounce on some addresses. Running the Apify verifier before the send turns most of those bounces into skips at the cost of a small bill against the user's own token.

The repository is a few days old, so the question of whether the YC directory stays scrapeable is open. If YC changes the shape of the directory page the loader stops working, which is the trade for building the tool on a public page rather than a paid list.

Source

Primary source: adityajha2005/yc-outreach on GitHub.