Show HN: Index – New Open Source browser agent | Hacker News Reader

Show HN: Index – New Open Source browser agent

github.com

98 pointsskull888888845 comments

Hey HN, Robert from Laminar (lmnr.ai) here.

We built Index - new SOTA Open Source browser agent.

It reached 92% on WebVoyager with Claude 3.7 (extended thinking). o1 was used as a judge, also we manually double checked the judge.

At the core is same old idea - run simple JS script in the browser to identify interactable elements -> draw bounding boxes around them on a screenshot of a browser window -> feed it to the LLM.

What made Index so good:

1. We essentially created browser agent observability. We patched Playwright to record the entire browser session while the agent operates, simultaneously tracing all agent steps and LLM calls. Then we synchronized everything in the UI, creating an unparalleled debugging experience. This allowed us to pinpoint exactly where the agent fails by seeing what it "sees" in session replay alongside execution traces.

2. Our detection script is simple but extremely good. It's carefully crafted via trial and error. We also employed CV and OCR.

3. Agent is very simple, literally just a while loop. All power comes from carefully crafted prompt and ton of eval runs.

Index is a simple python package. It also comes with a beautiful CLI.

pip install lmnr-index

playwright install chromium

index run

We've recently added o4-mini, Gemini 2.5 Pro and Flash. Pro is extremely good and fast. Give it a try via CLI.

You can also use index via serverless API. (https://docs.lmnr.ai/index-agent/api/getting-started)

Or via chat UI - https://lmnr.ai/chat.

To learn more about browser agent observability and evals check out open-source repo (https://github.com/lmnr-ai/lmnr) and our docs (https://docs.lmnr.ai/tracing/browser-agent-observability).

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Can it actually do something difficult like apply for jobs? So far I know of five or so websites that claim they can apply to jobs for you like sonara.ai and usemassive.com and Skyvern AI but when you try to actually use them all they can do is the one-page job applications and not the much more common Workday 10-page job applications with annoying "create an account" and annoying questions like "Do you have any relatives that work at Sony" and annoying "fill out all your work experience" where you have to click 50 times for one application. That's like half of all job applications. https://jobs.spectrum.com/job/-/-/4673/76746020384?utm_sourc...

I'm pretty confident it can do it. Try it out and see for yourself. Just install the package, run cli and give it your prompt.

pip install lmnr-index playwright install chromium index run

Also try experimenting with different models. So far, Gemini 2.5 Pro is the best in terms of quality/speed. Claude 3.7 is also pretty good.

shit, let me try it out

I consider using bad hiring software like that a red flag, and suggestive of other things the company must be doing wrong too. I noped out whenever I saw Taleo.

All big successful companies do "something" wrong, thats how they make money. Steal your OSS, not pay taxes, avoid overtime payments, low wages, outsource slavery, destroy the environment, gaslight while they steal your data and subject millions to dark patterns of advertising and marketing, screw over suppliers, intentionally sew discord as a distraction. The list goes on. To me the bigger the company the bigger the red flag.

That’s a very cynical view.

Do the biggest companies not create the most value for the world?

Consider this. If the most successful companies are simply cheating customers, then most consumers are stupid; handing offer their hard-earned money for bad deals and to be exploited.

But most people are not stupid, and most people highly value their money. So, they only buy something because they want what the seller is offering even more than their money. This means that companies create great value because they offer something that people really want.

This assumes there are compelling alternatives in the market that I can choose from. In reality, there are only a few entrenched players in any established market that work hard to limit competition. So yes, even if I'd like to choose not to hand over my hard-earned money to Evil Corp #93, I can only do the "stupid" thing and watch myself and my environment get exploited.

I disagree with the general comment that “any established market” has “only a few entrenched players”. I’d say that most markets provide compelling alternatives. Where they don’t yet, the product is either a commodity, or there is an opportunity for a new business to serve the customer!

But let’s say your point is true. How do those players become entrenched? I’d say it’s from providing great value.

Also, I don’t think my previous comment does assume that there are compelling alternatives.

A person always has a choice not to spend their money. Even if they need expensive healthcare, they can choose not to buy it. By buying the product, they want the service more than their money.

They might think that the price is too high, but prices are a function of market forces.

It doesn’t make sense to me that a person can say they feel exploited because they have voluntarily chosen to buy at a particular price. They probably want to pay less, and might feel that the consumer surplus is low, but they still value the service more than their money. That isn’t exploitation to me.

while we don't auto-apply to jobs for you, our browser extension, Simplify Copilot, makes it easier to apply to those multi-step application forms (workday, taleo, sap, etc.)

https://simplify.jobs/install

any need for browser agent observability?

Nice.

Can run with `uvx --from lmnr-index --python 3.12 index run`

How well does it work with bank websites with non-conventional multi-click logins that sometimes include an "important message" that you have to click through just to get your balance?

works pretty well, try it out - pip install lmnr-index

How do you force gemini or any other model to actually login to the bank system? Anything I try, I end up with "I can't do that as it's sensitive"

have you tried it with Index?

> Index is the SOTA open-source browser agent for autonomously executing complex tasks on the web.

I've written a handful of pretty hacky Python scripts that just pull down all of the HTML content from a page and toss it over to OpenAI. As you can imagine, these were all extremely simple tasks, e.g., "find out if there's a login button"

What's a good example of a complex task that Index is well-suited for? What's the threshold of minimal complexity where you guys are a really good fit?

- research task, agent is smart enough to understand which links to click next without the need to hardcode the parsing and navigation logic

- any task that requires UI interaction, button clicking, filter selection, form filling and so on. Just prompt it, it's surprisingly very robust and self-healing.

- complex long-running task that require extensive context - e.g. researching one topic and then creating spreadsheet, creating a presentation for a topic and so on.

Essentially, any task that can be done within a browser environment that previously required flacky hardcoded predefined scripts. Also, website testing is a great example.

Would love to see it doing some work on a Google spreadsheet (including doing formulas, vlookups, data import and cleanup) and then creating a decent Slides presentation with some charts from the spreadsheet

it can do it! try it out, literally just prompt it

Can you open up the options to use other model/versions, especially Gemini-2.5 pro experimental models available through aistudio? Would love to try this but gemini flash fails for even simple tasks. Example: I asked it to extract all the links from comment section of a hackernews comment section and it just scrolled all the way to the end and then nothing. Maybe pro models can do it better.

Gemini 2.5 pro is available. Is it missing on your side? Do you run index via CLI?

Yes it is, however API keys from aistudio only allows pro-experimental model. So if I select gemini-pro, I will see this: "Gemini 2.5 Pro Preview doesn't have a free quota tier. Please use Gemini 2.5 Pro Experimental (models/gemini-2.5-pro-exp-03-25) instead". Can I choose exact model somewhere in the CLI?

Oh I see, didn't know about that, fastest and easiest thing you can do is to play around with pro via our chat UI https://lmnr.ai/chat - it's free up to 10 messages.

For the CLI and custom models, you can clone the repo, then go to the cli.py and manually add your model there. I will work on proper support of custom models.

extremely slow

which model are you using? try gemini pro/flash, they are very fast

"Gemini Flash fails even for simple tasks." On the Gemini Flash page (https://deepmind.google/technologies/gemini/flash/), it claims to be 'best for fast performance on complex tasks.'. I always use Gemini Flash in my project for demos and testing, and it performs very well, if a project requires a large, expensive model to handle simple tasks, that could be an issue to users.

My first reaction was to look for MCP server so that I could connect it to Cursor. Just pointing this out in case it helps with new user onboarding. MCP server would work to hook it up to the Claude Desktop Website and most agentic-IDEs (Cursor, Cline, Roo, Windsurf, etc).

thank you for the feedback! we're actually working on it :)

What’s the most surprising or complex real-world task you’ve seen it succeed at so far?

researching a topic and creating a spreadsheet

I feel like I see a new company doing this every week. I know there is Skyvern and browser-use in particular. Is there something special about this one?

The best out all of them. Check the first message in the post. tldr:

- SOTA on webvoyager

- browser agent observability

- fast and reliable

- CLI for easier interaction

- available as a serverless API

Can I switch it to use my own models? Would it work with Gemma 3? Is vision required (Gemma 3 has it, but unsure if it supports coordinates)?

right now package only supports models from gemini, anthropic and openai. Vision is required. PRs are very welcome! It's very easy to add new model, simply follow any providers in here https://github.com/lmnr-ai/index/tree/main/index/llm/provide...

How do you perform actions with this agent? Puppeteer / playwright session?

playwright

How do I block it from my services? Does it obey robots.txt?

"That's the neat part, you don't."

If I wanted to use this to do my personal browsing for me, like checking for website updates on those where RSS does not exist, you shouldn't be able to stop me.

This is a user agent, not a recursive web crawler, so robots.txt explicitly does not apply [0]. As long as I'm not abusing your services you shouldn't care if my instructions to my user agent come in the form of a click of a button, a keyboard shortcut, a script, or an LLM agent.

If it's abusive behavior you are worried about you should be able to detect and block it with rate limits or other tools that target the malicious behavior. If you can't distinguish between my usage and a regular browser then I'm not sure what moral ground you have to claim my usage is hurting you.

[0] "A robot is a program that automatically traverses the Web's hypertext structure by retrieving a document, and recursively retrieving all documents that are referenced." https://www.robotstxt.org/faq/what.html

Impressive and potentially very interesting future work.

One thing I couldn't help but notice was the crazy amount of HTTP requests going on in the demo on the github readme page, and the video looks to be sped up.

I'm all for AI assisting but I wouldn't want to create even 1/10th of these HTTP requests, as a good netizen; unless I'm missing the point.

how could you see an http request from a video? If you mean the console output, then it's just logs of an agent.

got a video demo that isn't behind a sign up wall?

here's a demo of a chat UI https://x.com/skull8888888888/status/1910763169489764374

here's a demo of CLI https://x.com/skull8888888888/status/1914728292193628330

there's also a demo right in the repo https://github.com/lmnr-ai/index

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