A smart macro called 'AI Subroutines' has been unveiled, which records a person's browser tasks just once and repeats them infinitely without AI call costs (tokens) or waiting.
Imagine this. You’ve just arrived at work in the morning and need to send 100 connection requests on LinkedIn or manually enter dozens of contacts into a CRM system.
Using the currently popular ‘AI Agents’ (AI that judges and acts on its own to achieve human-given goals) can do this for you. But there’s a big concern. Every time the AI clicks or writes a sentence, expensive ‘tokens’ (the basic unit AI uses to process characters or information) are consumed. Moreover, while the AI is thinking (inferencing) about “Hmm… which button should I press next?”, you’re stuck staring at a loading icon on the screen.
To solve this inefficiency, a technology has emerged that, once taught, performs tasks perfectly and for ‘free’, much like playing back a video. This is ‘AI Subroutines’. Show HN: AI Subroutines – Run automation scripts inside your browser tab
Why is this important?
Until now, the ‘web agents’ we’ve encountered were only solving half the problem. AI Subroutines: Browser Automations That Run Inside the Page
According to an analysis by rtrvr.ai, the developer, AI already performs ‘one-off tasks’ like posting to Twitter or sending Instagram DMs excellently. However, the moment those tasks need to be repeated thousands or tens of thousands of times, the economics collapse instantly. It costs money every time it runs, speed is slow, and sometimes the AI makes strange mistakes. AI Subroutines: Browser Automations That Run Inside the Page
AI Subroutines completely change this ‘economics of repetition’ with three key strengths:
- Zero Cost ($0): Once taught, there’s no need to ask the AI model again. Therefore, there are zero token costs during execution. Show HN: AI Subroutines - Run automation scripts inside your browser tab
- Zero Latency: There is no ‘inference delay’ where the AI ponders the next move. The next step is executed instantly upon clicking. Show HN: AI Subroutines – Run automation scripts inside your browser tab
- Zero Chance of Error: Since it follows a script of actions already verified by a human, the risk of AI hallucinations leading to wrong clicks disappears. Show HN: AI Subroutines – Run automation scripts inside your browser tab
Easy to Understand: An Automated Piano Playing ‘Sheet Music’
This technology is like the difference between a ‘performer’ and an ‘automated piano’.
Existing AI agents are like pianists improvising in real-time. They have to think about what to play next in every measure. They can give moving performances, but they require high performance fees (token costs) every time and occasionally hit the wrong notes depending on their condition.
In contrast, AI Subroutines are like an automated piano with a ‘paper roll’ (sheet music) that records a pianist’s perfect performance exactly. Expert help is only needed when recording the performance for the first time; from then on, you just spin the roll. It doesn’t need to think, costs no performance fee, and plays infinitely and perfectly exactly as recorded.
This property of producing results exactly as determined is technically called ‘Deterministic’ (always producing the same result for the same input). AI subroutines bring zero-token browser automation
How does it work?
AI Subroutines work as an extension for browsers we commonly use, like Chrome. Show HN: AI Subroutines - Run automation scripts inside your browser tab
- Step 1. Recording: You perform a task on a website directly just once. At this point, the system meticulously records not only external actions like clicking or typing but also ‘Network calls’ (data signals exchanged with the website’s server) happening behind the browser. Show HN: AI Subroutines - Run automation scripts inside your browser tab
- Step 2. Conversion: The recorded content is saved as a ‘tool’ that can be executed without knowing complex code. Show HN: AI Subroutines - Run automation scripts inside your browser tab
- Step 3. Playback: Later, when needed, just by pressing this button, the script runs directly inside the browser tab, finishing the task in an instant. Show HN: AI Subroutines - Run automation scripts inside your browser tab
The smartest part is that it uses existing login information. Usually, automation programs find it very difficult to maintain logins due to security systems. However, because AI Subroutines operate inside a tab already opened by the user, they utilize the browser’s existing authentication info and security mechanisms. Show HN: AI Subroutines - Run automation scripts inside your browser tab Simply put, it’s like entering through a door the owner has already opened to help out, rather than needing to copy a separate key.
Current Status: A New Trend in Web Automation
Recently, web automation technology has been evolving rapidly. In the past, people scraped information secretly using headless browsers, but the latest tools in 2025-2026 utilize ‘live’ browser environments as if a person were using them directly to avoid surveillance by security systems. Browser Automation Frameworks Evolution in 2025: How They Adapt to Defeat Anti-Bot AI – Blog
| AI Subroutines presented by rtrvr.ai are at the peak of this trend. In Hacker News, the global developer community, they are already gaining attention as a powerful alternative to traditional, complex ‘RPA’ (Robotic Process Automation, technology where software replaces repetitive human tasks). [A New Revolution in Browser Automation? | AI Subroutines Let Scripts Run Themselves in Tabs | AI Mo Station](https://mobdome.com/blog/ai-subroutines-browser-automation-trend/) |
Of course, not everything can be solved with this technology. AI Subroutines are optimized for taking ‘paths already known’. If a website’s structure changes completely or if it’s a new task that requires complex real-time judgment based on the situation, the help of a ‘thinking’ AI agent is still needed. Browser Run: give your agents a browser
What will happen in the future?
| In the future, AI Subroutines are likely to become a ‘personal assistant toolbox’ for each of us. Just as the Arc browser recently introduced ‘Skills’ that use AI to organize tabs or automate specific functions, we will enter an era where we create and save frequently performed repetitive tasks as subroutines to take out and use whenever needed. [The State of AI Browser Agents in 2025 | FillApp Blog | FillApp - AI-Powered Chrome Extension for Form Filling](https://fillapp.ai/blog/the-state-of-ai-browser-agents-2025) |
If you’re wasting time filling out the same forms every day or gathering data from dozens of sites, AI Subroutines are now ready to give that boring time back to you. It’s as if a dependable assistant who says, “Just show me once, I’ll take care of the rest,” has taken a seat inside your browser.
AI Perspective
MindTickleBytes AI Reporter’s Perspective AI Subroutines are a very clever solution that breaks the stereotype that ‘AI must always use its head.’ They’ve proven that instead of searching with GPS every time, it’s much faster and more economical to record frequently traveled paths like black box footage and play them back. It suggests that the key to efficiency lies not in ‘what to automate’ but in ‘how to sustain it without incurring costs.’
References
- Show HN: AI Subroutines – Run automation scripts inside your browser tab
- AI Subroutines: Browser Automations That Run Inside the Page
- Show HN: AI Subroutines - Run automation scripts inside your browser tab
- Show HN: AI Subroutines - Run automation scripts inside your browser tab
- AI subroutines bring zero-token browser automation
- AI Subroutines - Run automation scripts inside your browser tab
- Show HN: AI Subroutines - Run automation scripts inside your browser tab
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[A New Revolution in Browser Automation? AI Subroutines Let Scripts Run Themselves in Tabs AI Mo Station](https://mobdome.com/blog/ai-subroutines-browser-automation-trend/) - Browser Automation Frameworks Evolution in 2025: How They Adapt to Defeat Anti-Bot AI – Blog
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[The State of AI Browser Agents in 2025 FillApp Blog FillApp - AI-Powered Chrome Extension for Form Filling](https://fillapp.ai/blog/the-state-of-ai-browser-agents-2025) - Browser Run: give your agents a browser
FACT-CHECK SUMMARY
- Claims checked: 20
- Claims verified: 20
- Verdict: PASS
- It costs expensive AI tokens every time it runs.
- Once a task is recorded, it repeats infinitely without extra cost or latency.
- The AI makes all decisions on its own without any human intervention.
- They automatically utilize security authentication (login status, etc.).
- They perform complex logical reasoning at every moment.
- They always handle tasks in new ways.
- OpenAI
- rtrvr.ai