[HN Gopher] Show HN: AI Subroutines - Run automation scripts ins...
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Show HN: 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 headers get added to all requests and propagate for free. No
certificate installation, no TLS fingerprint modification, no
separate auth stack to maintain. During recording, the extension
intercepts network requests (MAIN-world fetch/XHR patch +
webRequest fallback). We score and trim ~300 requests down to ~5
based on method, timing relative to DOM events, and origin.
Volatile GraphQL operation IDs are detected and force a DOM-only
fallback before they break silently on the next run. The generated
code combines network calls with DOM actions (click, type, find) in
the same function via an rtrvr.* helper namespace. Point the agent
at a spreadsheet of 500 rows and with just one LLM call parameters
are assigned and 500 Subroutines kicked off. Key use cases: -
record sending IG DM, then have reusable and callable routine to
send DMs at zero token cost - create routine getting latest
products in site catalog, call it to get thousands of products via
direct graphql queries - setup routine to file EHR form based on
parameters to the tool, AI infers parameters from current page
context and calls tool - reuse routine daily to sync outbound
messages on LinkedIn/Slack/Gmail to a CRM using a MCP server We
see the fundamental reason that browser agents haven't taken off is
that for repetitive tasks going through the inference loop is
unnecessary. Better to just record once, and get the LLM to
generate a script leveraging all the possible ways to interact with
a site and the wider web like directly calling backed API's,
interacting with the DOM, and calling 3P tools/APIs/MCP servers.
Author : arjunchint
Score : 21 points
Date : 2026-04-17 21:03 UTC (1 days ago)
(HTM) web link (www.rtrvr.ai)
(TXT) w3m dump (www.rtrvr.ai)
| rvz wrote:
| Aren't there just many ways for the website to just break the
| automation?
|
| Does this work on sites that have protection against LLMs such as
| captchas, LLM tarpits and PoW challenges?
|
| I just see this as a never ending cat and mouse game.
| acoyfellow wrote:
| It is. They are saying "we are willing to chase the mouse for
| you for money".
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(page generated 2026-04-18 23:00 UTC)