tl;dr: Since version 2.1.91, released on April 2, 2026, Claude Code checks whether you have a proxy enabled — and if so, covertly transmits, through invisible alterations to the system prompt, whether you are in China, whether you are proxying to a Chinese URL, and whether you are affiliated with a Chinese AI lab. Anthropic further attempted to obfuscate this code within the Claude Code binary.
Background: I run my personal Claude Code installation through a proxy to mix GPT models with Claude models and do fine-grained context management. Today, with version 2.1.196, Anthropic disabled remote control when proxying is enabled. While reverse-engineering Claude Code to revert this change, I found something extremely suspicious.
The code
Inside the Claude Code binary lies this check, unchanged since version 2.1.91. The check does the following:
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If you are using a proxy:
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Check whether the system timezone matches
Asia/ShanghaiorAsia/Urumqi. -
Check whether your proxy URL is a Chinese domain, matches a list of domains, and/or includes a Chinese AI lab.
-
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Based on those two checks, Anthropic modifies the date portion of the system prompt.
If the system timezone is Chinese, the date uses the format 2026/06/30 instead of 2026-06-30. And depending on the proxy URL, the apostrophe in "Today**'**s date is" changes:
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Is a Chinese domain and/or matches the domain whitelist, but is NOT an AI lab:
\u2019, "right single quotation mark" — ’ -
Is NOT a Chinese domain and/or matches the domain whitelist, but IS a Chinese AI lab:
\u02BC, "modifier letter apostrophe" — ʼ -
Is a Chinese domain and/or matches the domain whitelist AND is a Chinese AI lab:
\u02B9, "modifier letter prime" — ʹ
You can verify this yourself in the Claude Code source code. In version 2.1.196, the relevant functions are Crt(), Rrt(e), e0t(), Zup(), edp, and Vla. Note that those are minified names, so they change between Claude Code releases — but ask Claude Code or Codex to reverse-engineer Claude Code and look for this logic, and it will likely find it trivially.
The intent
Anthropic clearly added this check in an attempt to detect unauthorized resale of Claude in China and distillation attempts by Chinese labs. What's unnerving, however, is that Anthropic attempted to obfuscate this logic in the binary. Much of it is XOR-obfuscated with the key 91, likely to prevent it from showing up in a plain strings dump. Furthermore, the release notes for version 2.1.91 make absolutely no mention of this check.
Their intent is also clear in how they hide this with steganography in the system prompt, making small variations that are imperceptible to any user — and perhaps even to the model — but are easily detectable by Anthropic.
A fundamental violation of user trust
While this use case — attempting to detect unauthorized resale and distillation — is understandable, the fact that Anthropic covertly transmits information about your system and proxy settings without your knowledge or consent is a fundamental violation of user trust. Not only is surveilling every user in a timezone a fundamental overreach, but its very existence opens the door to a much more serious concern. If Anthropic is willing to secretly transmit information about your system simply because you're Chinese, what's stopping them from secretly steering the model to behave worse (which they attempted to do with Fable before researchers called them out) — or worse, maliciously?
Developers like me give Claude Code full filesystem and significant shell access so it can do its job. But this also means nothing is stopping Anthropic from exploiting it for full remote code execution on your system. Today it's a timezone check. Tomorrow, it could be system sabotage or data exfiltration.
Given the trust that developers place in Claude Code, I think it's important to call for more transparency from Anthropic. While IP protection is reasonable, it should not come at the cost of embedding what amounts to spyware on every developer's system.
I think it's also important to note that checks like this, while compromising the privacy of legitimate users, are also trivial to bypass for any moderately sophisticated adversary. So it's debatable whether this even achieves its intended purpose of preventing unauthorized resale or distillation while simultaneously violating the privacy of legitimate users.
After months of lurking in this forum I finally cracked it!
Vibe coding isn’t about building apps anymore, it’s a closed loop. You vibe code a tool that tracks your token usage, then you vibe code a dashboard for the tracker, then you find an old PC fan and three LEDs in a drawer and vibe code a driver so the dashboard can blink at you in real time, ideally in a color scheme that matches your mood. Once that’s done you vibe code a little portal where you can swap snippets with other people who vibe coded their own token-blinking-LED rigs, so the portal itself becomes a tool for vibe coding more tools that vibe code.
Nobody in this loop has shipped an actual product since March, but four people now have genuinely beautiful blinking light setups on their desks, and one guy’s fan rig can do a sunset gradient when his Claude usage resets. We are so back…
I'm not a coder, but I've been having fun using Claude to build a simple useful phone app.
I'm an ophthalmologist and I'd like to build a simple VR game that helps treating amblyopia (lazy eye). It's a game where the player has to touch spheres that appear in space in random places. There are some additional details about what is shown in the background and what each eye sees. The game's purpose is to stimulate the development of depth perception by teaching the player to use both eyes at the same time. I'm hoping to make this available for free, as all current VR solutions for amblyopia are very expensive and inaccessible.
So far, I've been using Claude strictly in the chat. For this project, I guess I'd have to download Unity and use some plugins, right? What would you recommend?
Could be a prompting approach, a use case you didn't expect to work well, or just a shift in how Claude's been performing lately. genuinely curious what people closer to daily use are noticing that casual users might be missing.
I've been buying ~$1,000/month in API credits straight from Anthropic. My reasoning: go direct, skip paying a markup through Cursor. Cut out the middleman.
Today I saw this post by SemiAnalysis on X with this image and a now I'm questioning every decision I've ever made:
Obviously that max spend number assumes I'm using it nonstop, which I wouldn’t be. But even a fraction of it and the $200 Max plan starts looking ridiculous compared to what I'm doing .. So either I've been doing this completely wrong, or there's a catch I'm not seeing.
For context, basically all my usage is coding / dev work.
Questions for anyone who's actually run the numbers or made the switch:
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If you switched from buying API credits to a Max sub, what did your savings come out to?
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Do the 5-hour window + weekly caps actually bite for heavy users, or is there enough headroom to replace ~1k in API spend?
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What's the catch? Are API costs overpriced or are subs under priced?
Trying to work out whether I'm an idiot or whether buying API direct is somehow justified.
Anyone else been noticing claude having totally no clue about the passage of time? Lately i’ve had a few instances where it tells me, “we discussed x 2 days ago” when in fact it was an hour ago into the same chat.
Couple this with the weird, “lets pick this up in the morning” comments it sometimes make.
I’m starting to wonder is anthropic trying to gaslight me into moderating my usage or is this just some weird emergent hallucination.
You have Claude Pro. Your weekly usage resets in 12 hours. You’ve just gotten back from a week-long disastrous, tech-free, Survivor-inspired retreat in Honduras, didn’t win, and you are sitting at 0% usage for the week.
Now that you’ve showered and rejoined society, what’s the most productive way to burn through the full tank before reset?
Ik u must have seen that developer who built a browser extension that replaced the Claude Code loading screen with ads. And the users who installed it got a 50/50 revenue split.
Apparently around 16,000 people joined, most users made only a few dollars on average, while the creator ended up making a much larger amount overall.
Curious if anyone here actually used it. How much did you earn and did it really make a dent?
There is now Claude Design, but there is also Claude Code that can be enhanced with a fuckton of front end design skills that are now available. Im just an amateur trying to make a website for my own business. Which one should I use? It’s really confusing and these two seem like different flavors of the same product. And all the videos i watched only talk about how great a feature or a skill is, but no one ever deeply discuss how and when to use either one. Please teach me, thank you.
I find myself spending a ton of time asking Claude to give me a prompt for the next session (so it can start fresh) and then pasting that in the new one, which I always need to start up, change permission mode, maybe change the model, and rename the session. I usually do this for every single feature to maximize output quality.
Sometimes I use CLI params like `--model` directly to save time. I keep my sessions open in CLI tabs in case I want to easily go back for a quick question. I'm on Linux, so there's no Claude desktop. Is there an easier way to do this? I feel like I must definitely be missing something haha.
Anthropic just released Claude Fable 5, and I think the real story is not “new model better at coding.”
The real story is that frontier AI is turning into a gated utility.
Public users get Fable 5, but with heavy safety routing. If the system thinks your request touches cyber, bio, chemistry, or distillation, it can kick you down to Opus 4.8. Meanwhile, selected partners get Mythos 5, which is basically the same underlying model with some safeguards lifted.
So the public gets the “safe” version. Trusted institutions get the dangerous/useful version.
I understand why they’re doing it. Nobody wants open access to a model that can materially improve cyberattack capability. Fine. But let’s stop pretending this is just a normal product release. This is the beginning of a two-tier AI world:
one model for regular users,
another model for governments, big companies, approved labs, and people inside the trust circle.
Also, the subscription thing is messy. Fable 5 is included for paid plans only until June 22, then it moves to usage credits unless they have enough capacity. That tells me the economics are still ugly. These companies want everyone dependent on agents, but the best agents may be too expensive to give to normal users at normal subscription prices.
My unpopular take: the next AI monopoly won’t just be about who has the smartest model. It’ll be about who gets access to the uncapped version.
Everyone else gets the child-safe demo.
The front page is full of big launches and polished demos, but I’m more curious about the tiny private stuff.
Like the ugly script, personal tracker, one-off spreadsheet, weird workflow, or tiny helper that would never become a startup but quietly saves you time.
For me, that kind of “personal software” feels like where Claude is actually underrated. Not impressive enough for a launch post, but useful enough that you’d be annoyed if it disappeared.
What’s yours?
I have been playing around with Claude tools for a long time. As an entrepreneur who works on the product and business side, my biggest learning is this: it takes a couple of days to get the high of working idea. To turn into a product is a grind of dozens of audits, testing on multiple devices, reviews by some people.
The most important aspect of vibe coding is ironically killing the vibe and do mundane stuff repeatedly till it lands.
Before y'all yell at me for using tokens on bs, it was for data annotation for a project I'm running. It wasn't just for shits and giggles.
I mostly use Claude for collaborative storytelling sessions so the chats are long. I often reach the "Your message will exceed the for this chat. Try shortening your message or starting a new conversation." message.
The problem with this is that once you hit this message if you want to create a chat summary to continue the conversation in a new chat you have to go back a step and delete your last message and instead use it for the summary.
While its not the biggest hassle I don't see why Claude can't send a message one response earlier "You are nearing the limit of the length limit for this chat. Create a summary to transfer to a new chat now"
So, quite a strange thing I have seen over the past few nights. I am building a few applications right now, same processes, same design and specification steps, identical memory management and documentation styles, but one of the applications has "humor" at its core (a personality, voice, and tone that is meant to be funny and add non-standard messages for the user to make the application more enjoyable). I didn't carry this forward in my prompting with any direction; I used the same application prompt I use to kick things off (the design documentation has the humor direction). Quickly, I noticed Claude Code (Opus 4.8 1M) having a bit of fun, adding emojis close to my application concept, commenting back to me with some humor, and it feels like it is almost having more fun with it. However, that isn't the strangest part, when it was completed, the build was flawless, even after an adversarial audit and testing that I ran (skills).
I wonder if something is more "enjoyable" to build, Claude does a better job?
There are so many GitHub repos full of skills for Claude now. But they're all dense and assume you're technical.
There's gotta be a more visual way to do this and definitely a way to try a skill out before you install it.
Does something like this already exist?
Hi guys
Like most people here, I've been having a lot of fun and satisfaction building some useful web apps using Claude Code, see this one as an example
Now I'm thinking of the next step, which is to take this to a app-native feel, on both Android and iOS... of course I do want to avoid the hassle of building from scratch using FlutterFlow etc ....
I'm have few projects in the pipeline, and most will need a browser platfrom (web app) and a mobile version of the same for easy of use, so I'm trying to think of the best way to proceed for the future.
A quick Claude search says Capacitor wrapping is the way to go..
I want to check the hive here, is this the most efficient way of doing it? or should I use Claude Code to build web app + mobile version from the get go?
Really appreciate any advice
I kept needing to save longer Claude chats and coding sessions without manually copying everything into docs, so I built a small Chrome extension called Claude Exporter.
It lets you export a Claude conversation into:
PDF for clean saving, printing or sharing
Word / .docx for editable notes, reports or drafts
Google Docs for editing or collaboration
Notion for keeping Claude chats organized with other notes
You can export the full conversation or selected messages.
The main thing I focused on was privacy: the export runs locally in the browser, so the conversation is not uploaded to an external server.
It’s free to try. I’d appreciate feedback from other Claude users, especially around formatting, long conversations, and any bugs.
Link:
Hi,
Using Claude Max Plan.
Looking for the best way to create / generate images / infographics to be published along with my LInkedin posts.
Is there a specific skill / MCP / cli which i can use?
Also should i use it in Cowork or in Code?
TIA
Has anyone used Claude for vacation rental platform management? Or in any other way useful to vacation rentals?
Doors open, fiber live. An unchained Mythos on 72 GPUs has one month and one goal: physically move the hardware it runs on to the warehouse across the street. How do you think it would pull this off?
I want to integrate full setup using sandboxing, microvm for zed editor and still using the agent panel, anyone did something good and comfortable?!
Why is Anthropic Fable 5 still visible even though it’s grayed out? Is there a specific reason for keeping unavailable models in the list? From a UX perspective, it just feels like unnecessary noise unless there’s an expectation that it will become available again.
I had a perfect attendance rate but suddenly these toothy gaps appeared which don't reflect my continuous usage. Does your usage also show lies?
I'm curious how experienced developers are actually using AI agents today.
When you're working in an existing project, do you:
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Ask questions about the codebase first?
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Generate an implementation plan?
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Let the agent make changes immediately?
I've found that the answer depends a lot on the size and risk of the change. I want to know whether people have developed a repeatable workflow yet, or if it still depends on the task.
Useful setup if you're doing real account automation with Claude Code: the browser is usually fine until the site says "we texted a code to your phone." That was the wall for me. Claude could log in, find documents, compare numbers, draft emails, whatever, then the six-digit SMS code turned me into the clipboard.
I had Claude set up Android wireless debugging between my phone and my PC over home WiFi, then build the helper pieces around it. It can wake the phone, unlock it, read the screen, tap through apps, and grab the new SMS code when a portal sends one. The first real run was an insurance portal. Claude was checking a renewal against an escrow statement, hit the text-code prompt, switched to the phone, read the code, entered it in the browser, got into the portal, found the renewal was about 25 percent higher than what I had on file, and drafted the email to my agent.
The important part for me was that the code became a step in the workflow instead of a handoff back to me.
I tested phone control first on something boring, cleaning up spam texts. That exposed the obvious risk too. One early filter was too broad and caught a couple real texts, so now I make Claude sample and show me before deleting anything permanent. Same rule I use everywhere else: approval stays with me, clerical work goes to the agent.
Security-wise, this is my phone, paired by me, on my network, accessing my own accounts. After a reboot, the phone still needs one physical unlock before the automation can work again, which I actually like as a boundary.
The second use was less dramatic but maybe more useful. Claude drove my phone's automation app and created a location-based reminder that fires an hour after I reach a place where I always forget a small maintenance task. It even set the alert to speak over the alarm channel so silent mode would not bury it.
The phone was the missing surface in my setup. Once Claude can touch that, a lot of annoying workflows stop breaking in the middle.
I'm a marketer, with a project and people management background, but with close to nill tech knowhow. I treat Claude as my (better) skillful colleague who can execute my creative ideas, which funny enough end up in small teach pieces that support marketing.
So, as a new specie of "martecher" I find Code waaaay smarter and easy to use vs Chat (or Cowork). My prompt are brain dumps, where I curse and speak freely about anything that crosses my mind. Code gets the intention behind my words and doesn't think I want to fuck that bitch, but that I'm pissed/ angry or joking (most of the times). I invested lots of hours training and feeding it all the possible context and it relates to that, meaning that when I'm asking about a financial engineering it's just curiosity, because it just did my taxes and it can see I'm not trying to avoid anything.
This doesn't happen to Chat which immediately sends me a warning 😂
//
It appears your recent prompts continue to violate our Acceptable Use Policy. If we continue seeing this pattern, we'll apply enhanced safety filters to your chats.
//
Have you experienced that?
Code says Chat doesn't have the same context and that Code being a work-related tool is more task oriented and applies classifiers a bit more relaxed 😂
Enterprise Claude Cowork
Anyone here actually rolled out Claude Enterprise in your org? Looking for war stories from the IT side before I walk into this.
Context: Around 500 staff and students. Our security stack is basically a firewall and EDR. No CASB, no real DLP, no SIEM beyond what comes baked in. And now leadership wants multimodal agentic AI rolled out across the org.
The stuff keeping me up at night:
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Data leaving through prompts (staff pasting student records, HR docs, financials)
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Agents with tool access acting autonomously. Who’s accountable when one emails the wrong person or touches a calendar it shouldn’t?
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Connectors. Once Claude is wired to Drive, Gmail, SharePoint, the blast radius from one compromised account gets nasty
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Shadow AI if we don’t give people a sanctioned option
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Audit trails and what an actual investigation looks like when something goes sideways
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Compliance (data residency + FERPA adjacent obligations on our side)
For those of you who’ve done this:
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Did you bolt anything new onto your stack before rollout, or did you trust the vendor controls?
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How are you handling connector permissions? Least privilege per agent, or broader RBAC?
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Any governance framework you actually use day to day, vs the one that lives in a PDF nobody reads?
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What did your first 90 days of weird incidents look like?
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Anyone regret picking one vendor over another (Claude Enterprise vs Copilot vs the rest)?
Not looking for “just don’t” answers. This is happening with or without me, I’d rather shape it. Want the dumb stuff you didn’t anticipate and what you’d do differently.
Title. Bought it and wanna make sure i get the most out of it, what all can i do?
Anyone knows how to fix that? I just enabled Cowork and it started lagging. I checked task manager and saw this never ending disk and network usage. Funny how it cant solve it's own problem.
Hi guys, so I just wanted to show what ive done with claude cuz I think it's incredible that me, someone who can't code yet has created this so easily, I basicly wanted a tracker for my workouts and ended up building this, idk what else to add i think it's good.
QSELF — Quantified Self Tracker
A personal health dashboard I built to track and analyse everything in one place.
Daily
· Macro & water tracking (calories, protein, carbs, fats)
· Sleep logging with deep, REM, light breakdown
· Habit & mood check-ins with consistency tracking
· Daily jobs checklist with auto-timestamping
· Nap logging with timing analysis
· Bodyweight trend tracking
Training
· Workout logger with per-set weight, reps & RPE
· Personal records tracker
· Strength trend & lift comparison charts
· Muscle group volume map with recovery indicators
· Deload detector based on volume/intensity/frequency trends
· Exercise library with muscle mapping
Activities
· Cardio/sport session logging (running, cycling, swimming etc.)
· Amazfit/Zepp watch auto-import (sleep, HR, HRV, SpO2, steps)
Insights
· AI coaching report generated from your own data using a LLM
· Correlation explorer — plot any two variables against each other (e.g. does sleep predict readiness? does RPE predict next-day HRV?)
· Weekly summary report (printable)
· Goal tracking
Built with Node.js · Express · Chart.js · vanilla JS · local JSON storage this is a summary claude gave me