Show HN: Browser Harness – simplest way to give an AI control of a real browser https://ift.tt/Q5ClUYP
Show HN: Browser Harness – simplest way to give an AI control of a real browser Hey HN, We got tired of browser frameworks restricting the LLM, so we removed the framework and gave the LLM maximum freedom to do whatever it's trained on. We gave the harness the ability to self correct and add new tools if the LLM wants (is pre-trained on) that. Our Browser Use library is tens of thousands of lines of deterministic heuristics wrapping Chrome (CDP websocket). Element extractors, click helpers, target managemenet (SUPER painful), watchdogs (crash handling, file downloads, alerts), cross origin iframes (if you want to click on an element you have to switch the target first, very anoying), etc. Watchdogs specifically are extremely painful but required. If Chrome triggers for example a native file popup the agent is just completely stuck. So the two solutions are to: 1. code those heuristics and edge cases away 1 by 1 and prevent them 2. give LLM a tool to handle the edge case As you can imagine - there are crazy amounts of heuristics like this so you eventually end up with A LOT of tools if you try to go for #2. So you have to make compromises and just code those heuristics away. BUT if the LLM just "knows" CDP well enough to switch the targets when it encounters a cross origin iframe, dismiss the alert when it appears, write its own click helpers, or upload function, you suddenly don't have to worry about any of those edge cases. Turns out LLMs know CDP pretty well these days. So we bitter pilled the harness. The concepts that should survive are: - something that holds and keeps CDP websocket alive (deamon) - extremely basic tools (helpers.py) - skill.md that explains how to use it The new paradigm? SKILL.md + a few python helpers that need to have the ability to change on the fly. One cool example: We forgot to implement upload_file function. Then mid-task the agent wants to upload a file so it grepped helpers.py, saw nothing, wrote the function itself using raw DOM.setFileInputFiles (which we only noticed that later in a git diff). This was a relly magical moment of how powerful LLMs have become. Compared to other approaches (Playwright MCP, browser use CLI, agent-browser, chrome devtools MCP): all of them wrap Chrome in a set of predefined functions for the LLM. The worst failure mode is silent. The LLM's click() returns fine so the LLM thinks it clicked, but on this particular site nothing actually happened. It moves on with a broken model of the world. Browser Harness gives the LLM maximum freedom and perfect context for HOW the tools actually work. Here are a few crazy examples of what browser harness can do: - plays stockfish https://ift.tt/kxg7Rmy - sets a world record in tetris https://ift.tt/zGIoVcJ - figures out how to draw a heart with js https://ift.tt/vxnutzy You can super easily install it by telling claude code: `Set up https://ift.tt/EklFyjY for me.` Repo: https://ift.tt/EklFyjY What would you call this new paradigm? A dialect? https://ift.tt/EklFyjY April 24, 2026 at 04:31AM
Show HN: Learn conflict resolution through a 90-second interactive story https://ift.tt/lM3C1dp
Show HN: Learn conflict resolution through a 90-second interactive story https://ift.tt/hxv0feU April 23, 2026 at 08:51PM
Show HN: leaf – a terminal Markdown previewer with a GUI-like experience https://ift.tt/UO3idIE
Show HN: leaf – a terminal Markdown previewer with a GUI-like experience https://ift.tt/HKYEWFc April 24, 2026 at 12:54AM
Show HN: LocalLLM – Recipes for Running the Local LLM (Need Contributors) https://ift.tt/InbTD9H
Show HN: LocalLLM – Recipes for Running the Local LLM (Need Contributors) I built localLLLM: a small community project for running local models. Live: https://ift.tt/lVFI6Wj The goal is simple: if someone has model + OS + GPU + RAM, they should get steps that actually work (ideally one liner) I need help populating and validating guides. If you run local models, please submit one working recipe (or report what failed). Would love to hear general feedback as well! https://ift.tt/lVFI6Wj April 23, 2026 at 05:01AM
Show HN: Honker – Postgres NOTIFY/LISTEN Semantics for SQLite https://ift.tt/4J0xlRb
Show HN: Honker – Postgres NOTIFY/LISTEN Semantics for SQLite https://ift.tt/OZuk6FN April 23, 2026 at 01:53AM
Show HN: Built a daily game where you sort historical events chronologically https://ift.tt/KEHmI73
Show HN: Built a daily game where you sort historical events chronologically https://hisorty.app/ April 23, 2026 at 12:14AM
Show HN: We built an OCR server that can process 270 dense images/s on a 5090 https://ift.tt/rxTGtVz
Show HN: We built an OCR server that can process 270 dense images/s on a 5090 https://ift.tt/FfLbJyz April 22, 2026 at 11:21PM
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