Precursor

(blog.cloudflare.com)

100 points | by AznHisoka 2 hours ago ago

84 comments

  • Havoc an hour ago

    It’s a bit alarming how cloudflare is establishing itself as arbiter of all things bots…both on blocking and allowing.

    Doesn’t seem healthy for the internet as a whole

    • postalcoder 30 minutes ago

      Gonna zag here. If you take a step back, cloudflare has been paving the path for pay for crawl. I think it's a noble and ambitious goal.

      While I can understand why you would be alarmed, I can point to almost two decades of lamenting on this forum about how we need better ways of rewarding content creators than ads. Well, this is it.

      Moreover, these products weren't built in a vacuum. Most threads about Anthropic and OpenAI have complaints about how these companies were built on stolen content. There's a reality we have to face here and we can't have it both ways.

    • whatjustin 3 minutes ago

      Unfortunately a common occurrence in the world. Not really a fan of cloudflare selling to both sides.

    • skybrian an hour ago

      Yes, but it’s up to their competitors to build competing services.

      • cryo32 an hour ago

        I think it's up to their customers not to encourage consolidation.

        • grim_io an hour ago

          Microsoft is the proof that customers do want that, or that they don't have a real choice.

          • cryo32 an hour ago

            I think it's simpler - they don't give a crap.

            Until somewhere down the line. Like when half of Spain gets cut off due to an arbitrary block on a consolidated service facade...

        • Tade0 39 minutes ago

          Customers shouldn't have to micromanage every service and product like that.

          We have antitrust regulations for such things.

        • Catloafdev an hour ago

          What Cloudflare competitors offer a similar range of services?

          • cryo32 an hour ago

            Do you really need Cloudflare's services to run your business?

            • Catloafdev an hour ago

              Are you genuinely asking "does anybody even need any of their services"?

              • yjftsjthsd-h 16 minutes ago

                You said "a similar range of services". Basic DDoS protection is probably important, and there are other companies doing that. Beyond that, it's less obvious.

              • cryo32 an hour ago

                Yes. I am asking exactly that objective question.

                They are advantageous to leverage in certain situations but essential they are not. We're used to, in the technology industry, looking for or creating problems to solve with services we are aware of. Moving back to necessity and need, do we really? Are we being objective? Most of the time, no.

                • dpoloncsak 37 minutes ago

                  Theres a few alternatives, but at a minimum yes you probably need their or a competitor's Name Servers and their public DNS. Rolling your own isn't very feasible.

                • Catloafdev 33 minutes ago

                  DDoS protection is pretty essential. I highly encourage you to read through what they offer if you're not familiar.

        • skybrian an hour ago

          That too, but they need competitors to switch to.

    • jppope an hour ago

      Agreed, but we should be honest, the internet today is far from healthy

    • hoppp an hour ago

      It's business as usual and it's our job to vote with our wallets.

    • cryo32 an hour ago

      Apart from handling of abuse reports. Yeah we're acting as CDN for this phishing site - we'll just inform the upstream about it and do nothing.

    • ianm218 an hour ago

      For any one of their product there is a good opportunity to build an open source alternative or something like it! Can be hard to work around they have the benefit of being able to have negative unit economics on lots of infra products... But people succesfully built tons of alternatives to google analytics and similar.

      • ralegh 23 minutes ago

        Open source for bot protection specifically would be difficult. If I as a bot developer can see the tests you run I can just modify my bot to pass them (either trivially or by brute force).

      • esseph an hour ago

        What they are doing requires both physical and digital infrastructure spread throughout the globe. It's not a cheap task.

    • Catloafdev an hour ago

      They're creating optional opt-in protection layers for the services they operate.

      I genuinely don't understand these generic complaint comments.

      Are you complaining that they offer too much? Or do you believe nobody is offering similar services?

      • stuartjohnson12 an hour ago

        The complaint is that the offer is a great deal with no downsides for consumers, and this is likely to result in Cloudflare having a lot of power (which they currently don't have) as a market maker. This position as market maker would grant them the power to extract economic rent from the web economy by charging both sides of the web provider and web consumer market to get access to the other.

        • Catloafdev 43 minutes ago

          So the complaint is that one day they have such a strong monopoly that they can freely turn evil?

          Just want to make sure I understand the real issue here, because that sounds like a lot of fearmongering to me.

    • dzonga an hour ago

      have you considered the alternative ?

      where bots run rampant ?

      trust me as an operator - I'm grateful Cloudflare exists.

    • baq an hour ago

      ...but very bullish NET. who wouldn't want to be the toll booth where you collect money both ways

    • Maxion an hour ago

      To be frank, their products do work and are sorely needed.

  • sudb an hour ago

    Cool product launch, though it feels a little weird to me that Cloudflare sells agentic products alongside this new service that seems designed to block agentic usage of the web?

    I expect there's much more going on than just mouse path detection but I can imagine that this is already tricky for touchscreens and for people using non-traditional mouse inputs (the thinkpad nub comes to mind - but it would also be bad optics to accidentally block people using accessibility mouse tools as bot users, though then this becomes a loophole for agentic browsing!)

    In general though I think this is almost definitely a good thing to reduce agentic bot abuse & spam.

    • skybrian an hour ago

      It’s less weird if you think there’s a difference between good bots and bad bots. They can provide services for good bots to use while helping people keep out the bad ones.

      If a bot is simulating mouse movement but doing it badly then that’s a strong signal of shenanigans. A good bot will obey robots.txt and do nothing to hide that it’s a bot.

      • pryelluw an hour ago

        Who gets to decide what is a good bot?

        • pythonaut_16 an hour ago

          Presumably the site owner with Cloudflare providing enforcement.

          Generally isn't a good bot one that respects robots.txt and is respectful of the site's resources by not being spammy?

        • wnevets an hour ago

          by checking which follow robots.txt?

        • nullpoint420 an hour ago

          Cloudflare, apparently.

        • tccole an hour ago

          Me… obviously

    • nozzlegear an hour ago

      > Cool product launch, though it feels a little weird to me that Cloudflare sells agentic products alongside this new service that seems designed to block agentic usage of the web?

      Feels a little bit like the mob selling "protection" to shop keepers.

  • akersten an hour ago

    control+F accessibility no results

    Yeah so this mouse movement astrology is going to completely lock non-sighted/keyboard only users out of large swaths of the Internet isn't it.

    • abirch an hour ago

      I'm guessing it's going to lock the non-sighted//keyboard only users out of the anonymous Internet. I'm guessing if you log in and give up your anonymity they'll consider you not a bot.

    • sudb an hour ago

      I'd imagine that mouse movement is just one signal among many that's weighted appropriately, but I hope we get feedback from these users

    • kingleopold 42 minutes ago

      just like how smartphone developers, engineers locked people with no smartphone.Some of the users that can no longer get services are really old people, disabled. In some well developed places on earth, you can't even check in flights without a smartphone, it's not even possible to travel for them.

      Yet all people are ok with it

    • DrammBA an hour ago

      cmd+F mouse movement 3 result, 3/3: "Mouse movement is just one example of the signals Precursor evaluates"

    • nojs 38 minutes ago

      I mean CF already forces 5 minutes of motorbike identification on anyone not in a whitelisted western country, so a small percentage of blind people is unlikely to worry them.

      • eastdakota 2 minutes ago

        You’re confusing us with Google. We don’t have a visual CAPTCHA.

  • reluctant_dev an hour ago

    What prevents bots/agents from just adding "jitter" to their movements that mimics how humans move their cursor?

    I know there are other signals being used but this one in particular seems like it wouldn't be hard to beat with a small amount of sophistication from the bot.

    • nerdsniper an hour ago

      Beating this would require a large amount of sophistication, not a small amount.

      Basic machine learning clustering will expose bots mouse+keyboard+touch behavior and discriminate them from humans.

      It will also likely discriminate against anyone with a disability and therefore using affordances like eye tracking. Just imagine how different a person with only one hand would look compared to a “typical” user!! This shouldn’t be too much of a problem in the USA because no one is enforcing the ADA at the moment outside of California / Illinois / NY.

      But I’m curious to hear from ‘eastdakota how they plan to guarantee that users with disabilities won’t be affected by these kinds of behavioral analysis. Cloudflare has such a massive footprint that it’s absolutely critical for them to err on the safe side of filtering, assuming they desire to be ethical.

      The immoral thing for cloudflare to do would be to say “we just provide a ‘bot likeliness score’ and it’s up to each website to decide what threshold they need”. And then wave their hands and say “we’re not the ones blocking users with disabilities…the websites are the ones setting their thresholds too strictly”.

      When you reach Cloudflare’s size … you own all the 2nd and 3rd order effects of your decisions.

      This kind of data not only separates bots from humans - it’s pretty trivial to distinguish male vs female, right-handed vs left-handed, approximate age, native language (based on keyboard input patterns), state of injury (including tracking progression of healing), and a variety of different mental/physical disabilities. How one navigates a website tells you whether they are ADHD or schizophrenic or has Parkinson’s, and it can tell you about drug use/abuse: how well is this person’s Parkinson’s treatment working? What days of the week does that person tend to abuse amphetamines?

      It is super difficult to mimic all of these signals in a way that would cluster the same as typical humans.

      • SoftTalker an hour ago

        We used to say the same sorts of things about LLM prose, music, and image generation. Now just a few years later it can be very difficult to know for sure if something is made by AI or a human. There are still tells, but they are much more subtle and harder to spot, and models are still improving. Mimicing human mouse movement won't be any more of a challenge.

      • lossolo 10 minutes ago

        > It is super difficult to mimic all of these signals in a way that would cluster the same as typical humans.

        Not really, beat ML with ML. I won't disclose how to do it, because who knows who might read this, but you can easily do it with a model trained for that purpose.

    • fwlr an hour ago

      The jitter you add has to specifically be “jitter that mimics human cursor movement”, which is extraordinarily non-trivial to synthesise.

      • SAI_Peregrinus an hour ago

        No, it's "jitter that mimics human cursor movements detected by Cloudflare's Precursor script". It'll just be another arms race.

        • sbarre an hour ago

          Like any other detection system you will always have determined adversaries that put in the work to bypass it.

          But that doesn't mean you shouldn't still try to block the much larger number of less sophisticated/resourced adversaries that are using OOTB libraries and low-effort setups.

      • justinhj an hour ago

        are you sure it's non trivial? they posted a 2d image of what it looks like. a fairly simple model of the users wrist and mouse position doesn't seem crazy hard but the devil is in the details

    • stogot an hour ago

      In 2027 how many tokens will we spend to create the jitter, pre-jitter planning, post-jitter verification, and then cloudflare’s inevtiable counter-jitter

      • zdc1 an hour ago

        Someone needs to vibecode a "virtual mouse" tool for the agents to steer instead (semi /s)

        • teravor 10 minutes ago

          that's actually how you do it. adversarial systems like those are prime candidates. one agent develops detection mechanisms and the other agent defeats them. progression signal is easy to get.

          and you bootstrap with existing javascript detection engines.

          the challenge is usually the human input data, your objective is to be clustered among the humans and for that you need to know what humans look like.

          this is not an open ended arms race, it will end once the bots approximate humans to a sufficient degree - false positive rate for detection will become unacceptable even if the detection system is slightly ahead.

    • kypro an hour ago

      There's always been an arms race in anti-bot technology and more sophisticated bots.

      I'm sure, they can add a jitter, but then you just change how you detect / weight detection.

  • TrackerFF an hour ago

    One interesting aspect is of course that the movement from the same user can be different depending on what type of mouse they use. I use a mouse at work on my PC, touchpad on my private laptop, and thinkpad nipple on work laptop. Three different profiles for one user.

    Obviously different movements from a AI, but if we come to the day where mouse movement fingerprinting becomes another gatekeeper, there could be some interesting outliers.

  • amirhirsch 31 minutes ago

    I implemented all of this in hCaptcha 6 years ago, not just to distinguish bot from human but also to recognize the keyboard/mouse behavior of the same person signing up for many accounts or testing multiple credit cards. This kind of abuse detection was a part of Cloudflare when they switched to hCaptcha in 2020 and I had thought they already implemented all this themselves four years ago when they transitioned away from hCaptcha in 2022.

  • nearlyepic an hour ago

    I can’t wait for cloudflare to sell data on how well my wrist is working to my insurance company. What a wonderful hell we’ve created for ourselves.

  • khurs an hour ago

    Cloudflare has a lot of enterprise customers. Selling bot check to companies wanting to protect their content & also taking a cut out of payments for access by bots could be a good earner for them.

  • tavavex 44 minutes ago

    It's a bleak world in terms of bots flooding the web, but out of all possible solutions, this seems to be preferable over invasive and identifying fingerprinting that everyone wants to roll out. Here's hoping that mouse movements aren't sufficiently unique as to be fingerprintable too.

  • erikvanoosten 15 minutes ago

    Your keyboard and mouse rhythm and timings are probably so unique that they can be considered PII. Wonder how that works out legally.

  • pllbnk an hour ago

    I have been noticing a lot of Cloudflare false positives where it keeps spinning on my sessions never actually redirecting me to the underlying page. If they keep just vibe coding and releasing a new solution every day, I am afraid it will be reflected in their services quality.

    • mial an hour ago

      Sometimes it might be your user agent, or your IP, or some browser extension…

    • dubcanada 37 minutes ago

      I get flagged way more often on Starlink then I did on my local ISP fiber.

  • kurtoid an hour ago

    how does this interact with keyboard navigation & accessibility tools?

  • dubcanada an hour ago

    There is nothing stopping a bot from moving their cursor like a human. This is basically just putting up a door with zero walls and telling people to stay out of your house.

    All of these things are completely abusable/bypass-able and just annoying for actual humans who trigger flags.

    • swiftcoder 42 minutes ago

      > There is nothing stopping a bot from moving their cursor like a human.

      Sure, we could write a library that slows the bot down and makes it move the cursor in procedurally-generated curves with a certain degree of noise added... but its all extra work, and it all slows the bots down. Presumably they wouldn't reveal that part of the secret sauce if it was all of the secret sauce

      • dubcanada 38 minutes ago

        Acting like a human is something scapers already do. Using residential proxies, using latest Chrome user agents, not moving/typing as fast, etc. This is just 1 more layer, moving mouse naturally.

  • dinkleberg an hour ago

    I wonder how it'll handle those of us who try and use the mouse as infrequently as possible. I imagine the cognitive delay part would be largely telling. But it'll be interesting to see if I start getting blocked because I use vimium.

    • SoftTalker an hour ago

      I think it doesn't really matter, the bots will adapt with much more human-like mouse movement very quickly.

  • trunnell 27 minutes ago

    I dislike bots as much as anyone else... when weird inquiries come through my company's lead form, it costs some time and attention to sort them.

    But what makes Cloudflare so confident that automation always equates to "fraud and abuse?" If I send my agent to go retrieve some information, do they consider that fraud?

    If I block various ad trackers does that trigger their "bot detection" incorrectly? Do I have any recourse? Or is Cloudflare appointing themselves judge, jury and executioner?

    And let's not forget this little chestnut: > 4. Privacy by design. Precursor was designed to collect signals that help to distinguish human patterns from automated and abusive patterns.

    Ahh, so to "protect" against bots they're standing up a whole new regime of user surveillance and session-level monitoring. And they definitely won't be selling that, they promise. Got it.

    This crap should be illegal. In the real world, I can authorize others to act on my behalf. The same should be true with software agents.

  • timcobb an hour ago

    Gosh, this is all pretty nauseating.

  • PessimalDecimal 2 hours ago

    Is this equivalent to Google Cloud Fraud Defense? https://cloud.google.com/security/products/fraud-defense

    • eth0up an hour ago

      Not sure, but I struggle with skepticism for anyone who blocks archive.today, which cloudflare does, along with nextdns and others. Being blocked by such a large... apologies in advance for 'lack of better word' vernacular, cartel, is a near death sentence.

      Not a fan

      • nerdsniper an hour ago

        CF doesn’t block archive. Archive poisons CF. Explanation direct from the CEO of CloudFlare: https://news.ycombinator.com/item?id=19828702

      • pests an hour ago

        archive.today was running a DDOS through their CAPTCHA page

        • eth0up an hour ago

          Although the blocking of archive.today goes back years, as can be verified through forum searches and archives with nextdns and others, I was not aware of this and have no excuse to dispute it. But for the record, the blocking predates 2026 by many years -- and my own records also verify this. That said, I think I need to learn more.

  • whimsicalism 34 minutes ago

    as a heavy user of computer use, i hope enterprises realize that people like me will switch to competitors that support native computer use & APIs

  • freedomben an hour ago

    As a real user who uses an Ultimate Hacking Keyboard with the mouse layer, this frustrates me immensely. Yes I'm a corner case, but this is likely to make certain website not work for me because my lines are perfectly straight and my arcs zig-zag much like a bot might.

    Considering the keyboard/mouse layer feels like an advancement to me, this feels like tech that will lock in the "old" way of doing things.

    I really detest how adversarial the web is getting. I'm not a cloudflare hater but please, please consider people like me when rolling out stuff that affects millions or maybe even hundreds of millions or billions of people.

  • nullc an hour ago

    please drink verification can to continue

    • arm32 an hour ago

      Your children are now in custody of Carl's Jr.!

  • carterschonwald an hour ago

    even before the llm era sites would flag me as a bot for opening 15 links to read later. its fucking infuriating now

  • csomar an hour ago

    So now instead of having the slow-axx Cloudflare turnstile slowing down your requests, you get surprised with a "You are a BOT!!!" while you are conducting your business on a website.

    I already quickly close any website that I do not need for business purposes when it shows me the Cloudflare spinner. Now I might have to start considering competitors who do not implement this shit.

  • bellowsgulch 21 minutes ago

    Yawn. Train a domain-specific model on human inputs and then run inference against that. At integration, you change what, one line of code with another? You at best raise the expense to bot, but in today's world, this isn't much compute expense. You can do it on 10-year-old Xenon processors, the same ones used by companies promoted on LowEndBox.

    Skids already fall into the trap of using open source automation like playwright-extra-stealth.