Layer vs. ScreenCI

One API for prediction markets. Find markets, stream normalized data, place orders, and track positions across Kalshi and Polymarket. Hi HN, I'm David. I built Layer, an API + SDK or building trading bots/ai agents across prediction markets.The idea came from something i kept running into while playing with trading bots. Once your bot needs access to more than 1 venue, you suddenly have to deal with different market schemas, contract definitions, prices, fees and APIs before you can reason about where to trade. That gets messy real fast, especially with prediction markets. The same real-world event can exist on Kalshi & Polymarket, but the contracts can be represented differently.Here's my broader thesis:...

Tutorial videos of your app, made by your coding agent. Describe the feature in one sentence and paste one prompt into Claude Code, Codex, or Cursor. It records a narrated walkthrough of your real app on your own machine, and the finished video opens in your browser, ready for your help center or docs, where anyone edits the narration, voices, and 79 languages. Engineers can keep the videos in the repository as Playwright tests that CI re-records on every release. Hi HN, I'm Olli. My friend Patrik and I are bootstrapping ScreenCI: tutorial videos of your web app that you can re-record in your CI on every release. If the video is out of date, the run fails like any E2E test.I've been on teams where the tutorial videos were outdated, or even where we held back UI improvements due to manually maintained videos. That's why we built system where you can describe the videos as Playwright E2E test code. Coding agents are very good with writing tests and you can run these scripts against your app on your machine. ScreenCI converts them into narra...