AI Subroutines – Run automation scripts inside your browser tab
We built AI Subroutines in rtrvr.ai. Record a browser task once, save it as a callable tool, replay it at: zero token cost, zero LLM inference delay, and zero mistakes. The subroutine itself is a deterministic script composed of discovered network calls hitting the site's backend as well as page interactions like click/type/find. The key architectural decision: the script executes inside the webpage itself, not through a proxy, not in a headless worker, not out of process. The script dispatches requests from the tab's execution context, so auth, CSRF, TLS session, and signed…
AI Subroutines – Run automation scripts inside your browser tab launched on April 17, 2026 with 46 votes, #893 of 21,248 launches that month and more than 95% of that year's launches.
In plain words
AI Subroutines is a browser extension that lets users record repetitive tasks once and replay them as automated scripts with no token cost or processing delay. The tool captures browser interactions like clicks and typing alongside backend network calls, then runs the recorded script directly inside the webpage to preserve authentication and session data automatically. It is for anyone who performs routine web tasks repeatedly and wants to eliminate manual repetition.
written from the facts on this page · September 2026
From the sources
Turn a successful browser action into a deterministic routine that can run again without another planning loop.
In the maker’s words, at launch
We built AI Subroutines in rtrvr.ai. Record a browser task once, save it as a callable tool, replay it at: zero token cost, zero LLM inference delay, and zero mistakes. The subroutine itself is a deterministic script composed of discovered network calls hitting the site's backend as well as page interactions like…
Does a similar job
all alternatives →
Time travel debugger for web development2021 · replay.io · ▲681Automated Penetration Testing for AI-Built Apps
Webvizio for AI Coding Agents2025 · webvizio.com · ▲706Resolve dev tasks & bugs faster with Webvizio MCP
rtrvr.ai/exchange2025 · rtrvr.ai · ▲152No one’s got money for another AI subscription. So we made our browser agent totally FREE. What's the catch? Just ads while Retriever AI fetches you leads, does your exams, applied to jobs, and sends connection requests. Think like a Claude Code or Clay level tool in your browser, but free for everyone! After 35K+ users and 7M+ workflows, we spent the last few months attacking the cost of every agent step: - switching to DeepSeek Flash - Code Mode to one shot complex workflows - optimizing for 80%+ token cache hits So that now just an ad impression covers the entire cost of the agent (LLM…
Rover by rtrvr.aiFeb 2026 · rover.rtrvr.ai · ▲316Turn your website into an AI agent with one script tag.
Notte Browser Agents2025 · notte.cc · ▲275Hey HN, We’ve been building browser agents for a while. In production, we kept converging on the same pattern: deterministic scripts for the happy path, agents only for edge cases. So we built Demonstrate Mode. The idea is simple: You perform your workflow once in a remote browser. Notte records the interactions and generates deterministic automation code. How it works: - Record clicks, inputs, navigations in a cloud browser - Compile them into deterministic code (no LLM at runtime) - Run and deploy on managed browser infrastructure Closest analog is Playwright codegen but: - Infrastructure…
Libretto – Making AI browser automations deterministicApr 2026 · github.com · ▲134Libretto (https://libretto.sh) is a Skill+CLI that makes it easy for your coding agent to generate deterministic browser automations and debug existing ones. Key shift is going from “give an agent a prompt at runtime and hope it figures things out” to: “Use coding agents to generate real scripts you can inspect, run, and debug”. Here’s a demo: https://www.youtube.com/watch?v=0cDpIntmHAM. Docs start at https://libretto.sh/docs/get-started/introduction. We spent a year building and maintaining browser automations for EHR and payer portal…
More ai this month
the category →



Paintings by AI models: programs run through a simulation of oil paint.
AI · 20d ago · stillwet.art

PixVerse R2▲381A real-time world model you can explore and change
AI · 28d ago · world.pixverse.video
Source: Show HN post ↗ · launch text quoted in part
Launched alongside, April 2026
the whole month →
- AG
Thought the resources for GPU arch were lacking, so here we are
Life & fun · Apr 2026 · jaso1024.com

Built a ~9M param LLM from scratch to understand how they actually work. Vanilla transformer, 60K synthetic conversations, ~130 lines of PyTorch. Trains in 5 min on a free Colab T4. The fish thinks the meaning of life is food. Fork it and swap the personality for your own character.
AI · Apr 2026 · github.com


I made a laptop stand out of solid concrete, in the style of brutalist architecture, with themes of urbex and urban decay
Life & fun · Apr 2026 · sam-burns.com

With social media and now AI, its important to keep the indie web alive. There are many people who write frequently. Blogosphere tries to highlight them by fetching the recent posts from personal blogs across many categories. There are two versions: Minimal (HN-inspired, fast, static): https://text.blogosphere.app/ Non-minimal: https://blogosphere.app/ If you don't find your blog (or your favorite ones), please add them. I will review and approve it.
AI · Apr 2026 · text.blogosphere.app