upvote
Show HN: Libretto – Making AI browser automations deterministic

(github.com)

reply
I literally _just_ put up an announcement on our internal Slack of a tool I had spent a few weeks trying to get right. Strange to post the announcement and, literally the same day, see a better, publicly available toolkit to do enable that very workflow!

I'm also using Playwright, to automate a platform that has a maze of iframes, referer links, etc. Hopefully I can replace the internals with a script I get from this project.

reply
Haha that's wild, let me know if you run into any issues with it!
reply
I like the pre-gen approach! Curious how it responds to JS that changes how components are rendered at run-time.
reply
There are a couple ways to handle JS components rendered at runtime:

- Libretto prefers network requests over DOM interaction when possible, so this will circumvent a lot of complex JS rendering issues

- When you do need the DOM, playwright can handle a lot of the complexity out of the box: playwright will re-query the live DOM at action time and automatically wait for elements to populate. Libretto is also set up to pick selectors like data-testid, aria-label, role, id over class names or positional stuff that's likely to be dynamic.

- At the end of the day the files still live as code so you could always just throw a browser agent at it to handle a part of a workflow if nothing else works

reply
Love it! Do you have a BAA with Claude though? Otherwise, your demo is likely exposing PHI to 3rd parties and exposing you to risk related to HIPAA
reply
It's a good callout. We have a BAA + ZDR with Anthropic and OpenAI, and if you want to use libretto for healthcare use cases having a BAA is essential. Was using Codex in the demo, and we've seen that both Claude and Codex work pretty well
reply
I built something very similar for my company internally. The idea was that that the maintenance of the code is on the agent and the code is purely an optimization. If it breaks the agent runs it iteratively, fixes the code for next time. Happy to replace my tool with this and see how it does!
reply
Super cool! Please let me know how it goes. Since agents are so good at writing code, we think letting the agent rewrite/test the code on failure is better than just using a prompt at runtime
reply
Thanks for this! We have clear answers for things that are 100% and 0% automated, but it’s always that 80%-99% automated slice where the frontier is, great idea.
reply
script maintenance is exactly where that middle slice bites - the app keeps evolving and the scripts lag behind. we took the angle of having the agent re-explore from scratch each run with autonoma (https://github.com/autonoma-ai/autonoma) for e2e qa, no maintained scripts, adapts naturally - different goal than libretto but same core intuition
reply
how does it differ from playwright-cli?
reply
At its core, libretto generates, validates, and helps with debugging RPA scripts. As far as I understand tools like playwright CLI are more focused on letting your agent use playwright to perform one-off automations.

The implementation is also pretty different:

- libretto gives your agent a single exec tool (instead of different tools for each action) so it can write arbitrary playwright/javascript and is more context efficient

- Also we gave libretto instructions on bot detection avoidance so that it will prefer using network requests for automation (something that other tools don’t support), but will fall back to playwright if it identifies network requests as too risky

reply
I've wanted something like this for ages, excited to try this out!
reply
What is the license?

Edit: nevermind. I see from the website it is MIT. Probably should add a COPYING.md or LICENSE.md to the repository itself.

reply
Cool. Thank you for sharing. While AI tools are extremely powerful, packages like this help create some good standards and stepping stones for connectivity that the models haven’t gotten around to yet. Thanks again.
reply
this looks awesome
reply
this is interesting
reply
[dead]
reply
[dead]
reply
[dead]
reply
[dead]
reply
[dead]
reply
[dead]
reply
[dead]
reply
deleted
reply
[flagged]
reply
Ok, but please don't post unsubstantive comments to HN.
reply
Lol sorry for the misleading click. We named it libretto after the term in theater, inspired by Playwright. No retro gaming here, just browser automation!
reply
[flagged]
reply
Right now libretto only captures HTTP requests, which the coding agent can use to determine how to perform the automation.

For more complex cases where libretto can't validate that the network approach would produce the right data (like sites that rely on WebSockets or heavy client-side logic) it falls back to using the DOM with playwright

reply