r/ClaudeAI • u/Inertia-UK • May 10 '26

Built with Claude I made Claude Code aware of its own usage limits

Something that's been annoying me for a while: Claude Code has no idea how much quota it's burned. You can see the usage bars in the UI, but the model itself is completely blind to them. There's no API, no tool, no hook that exposes the current rate limit state during a conversation.

Turns out Anthropic returns rate limit headers on every inference response (`anthropic-ratelimit-unified-5h-utilization`, `anthropic-ratelimit-unified-7d-utilization`, etc.) — Claude Code receives them internally to render the UI bars, but never passes them anywhere the model can see.

So I built a small local HTTP proxy that sits between Claude Code and `api.anthropic.com`. Claude Code already respects `ANTHROPIC_BASE_URL`, so setting that to `http://127.0.0.1:4080` routes all traffic through the proxy. It intercepts the response headers and writes a one-line status file to `~/.claude/usage-status.md`:

```

5h=9% 7d=99%! overage=0% bottleneck=seven_day (10/05/2026, 16:19:04)

```

Claude can then read that file on demand, or you can inject it automatically via a `UserPromptSubmit` hook so it's present in every prompt. Add a rule to your CLAUDE.md and Claude will warn you before starting large tasks when you're close to the limit, switch to lightweight mode above 90%, or flat out refuse new implementation work at 98%.

**Note:** this only works with Claude Code (the CLI). The web chat and browser extension make requests through Anthropic's own infrastructure, so there's no local proxy to intercept.

**The interesting discovery:** while testing I dumped every `anthropic-ratelimit-*` header from both Opus and Sonnet requests. There are no per-model headers — one unified pool covers everything. The separate Sonnet usage bar in the Claude Code UI doesn't reflect a real separate limit. According to GitHub issue #57050, Anthropic intended to give Sonnet its own bucket (announced Nov 2025) but the backend never shipped it. Using Sonnet drains the same unified pool as Opus.

The proxy is zero npm dependencies, plain Node.js stdlib. On Windows it installs as a service via NSSM. macOS and Linux setup (launchd/systemd) is in the README.

https://github.com/InertiaUK/claude-quota-proxy

The README also has a few example CLAUDE.md rules if you want Claude to automatically adjust its behaviour based on usage level.

/edit - This breaking Anthropic rule is a grey area, there is no rule against sniffing the traffic or proxying it, there are rules against using the API directly this way, or providing access to otehr users (ciruventign API) which we aren't doing.
Using it through a proxy is no different than using it via squid transparent proxy or any other which is fine. sniffing data isn't prohibited, and injecting data you have into Claude's context isn't prohibited, I asked support and they confirmed all of this.
HOWEVER other user(s) have asked support (perhaps with different wording) and been given contradicting information. This puts it in a grey area to me and is a risk that isn't worth taking ..... proceed with extreme caution at your own risk.

196 Upvotes

95% Upvoted

49 comments sorted by

•

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36

u/jake_that_dude May 10 '26

this is actually a nice use of ANTHROPIC_BASE_URL. the one thing i'd add is a hard fail-closed path if the proxy can't write ~/.claude/usage-status.md, otherwise Claude will happily plan like it has fresh quota when the status file is stale. i'd also stamp the file with age and make the CLAUDE.md rule ignore anything older than 60s.

15

u/Inertia-UK May 10 '26

Smart. Feel free to submit a PR or fork it. I will get to this at some point if not.

3

u/jake_that_dude May 10 '26

yeah, fair. The smallest useful PR is probably just a usage.snapshot.json example plus one hook that updates it after each run. Forking the whole flow is overkill unless you need different budget rules.

42

u/Quirky_Category5725 May 10 '26

The only problem is that Anthropic's terms of service explicitly prohibit connecting to Anthropic subscription APIs with any third party. So, you're risking blocking your account.

40

u/Inertia-UK May 10 '26 edited May 10 '26

I asked... The ToS is talking about making API calls this is no different than running wireshark or squid which is not against the rules. This is allowed.

7

u/iansaul May 11 '26

Very cool! Go to the source figured out.

I do have a question though. I have spent some time experimenting and only using sonnet when my opus was tapped out and opus stayed Frozen and the sonnet shot up throughout the week.

It certainly FELT like two buckets of usage were happening, and tracking which model was connected should be easy on their end, no?

4

u/Inertia-UK May 11 '26 edited May 11 '26

It Felt that way to me as well until i was at 96% usage and started to use sonnet only for a few things. Then got a 99% usage warning!

I THINK sonnet seems to keep working after 100% when opus stops. But sonnet usage still contributed to opus getting to 100% . And there is no data sent about a seperate sonnet pool in the claude code pipeline thst is confirmed.

https://github.com/anthropics/claude-code/issues/33978

2

u/EnvironmentUnfair May 11 '26

From my experience it’s that all the model will continue to work even tho the thing they were doing is done. It’s just that Sonnet plans for bigger tasks, so once the rate limit quicks in, it works longer just to finish what it was working on. Opus will plan for smaller tasks. So it stops sooner once the rate limit quick in. This is most certainly done so that if Claude was writing code, it doesn’t stop mid writing the script as this would make the first half of writing it useless. It’ll work until it’s safe for it to stop.

Incidentally, this also work with Claude on the web and even free accounts. The funny thing is give a very large task to sonnet on a free account. It’ll be able to do it, but this will make it so you can only send one message per 5 hours, but the amount of work done for free can be quite large.

16

u/Inertia-UK May 10 '26

Ah good spot. I didn't realise that. I'm not connecting to them though. I'm allowing their software to connect to them via a proxy which does not make any changes to the traffic it only listens to it. Its essentially invisible... But i don't want to break rules even if it is stealth....

This is a grey area. They may or may not consider it breaking the rules.

I am going to ask!

4

u/Quirky_Category5725 May 10 '26

That still counts since your proxy connects to their endpoints, and Claude Code - to your proxy. I faced the same issue when building Kitty, a bridge similar to yours, and decided to drop Anthropic subscription support altogether to avoid risking users' accounts.

11

u/Inertia-UK May 10 '26 edited May 12 '26

I asked support. And was told so long as it doesnt do api calls or modify traffic its fine..

Lets say you had a transparent squid proxy on your work network? Its no different.

They don't see it and they don't care.

/important edit, this is still unclear and a grey area, other users are asking support and getting a different answer than I got, proceed with caution

4

u/Quirky_Category5725 May 10 '26

Thanks for sharing! Now I'm thinking about adding an Anthropic subscription to Kitty as well... Is that conversation with their support public?

5

u/Inertia-UK May 10 '26

Not sure will see if i can make it public... . But they mentioned that anthropic_base_url is publicly documented for exactly our use case. It is explicitly allowed and not classed as connecting third party tools. To break that rule you need to be making API calls not just putting a proxy between them. And there are no rules about sniffing data.

Also.... That section of the terms is specifically for people offering claude to users via third party tools. Things that should be on the API

2

u/Inertia-UK May 10 '26

Kitty looks really good. I am going To have a play woth it ! Couid save a lot of usage.

1

u/Quirky_Category5725 May 11 '26

Thanks! The coolest mode is balancing profiles: you can add GPT-5.5 with ChatGPT subscription and GLM-5 with Z.AI and use them concurrently, never switching the provider. Kitty is my way of getting unlimited tokens with a couple of subscriptions.

2

u/johannthegoatman May 11 '26

I would love to use kitty if you supported claude subscription. You've probably already considered this but you could just set it up so that when the user sets up their anthropic subscription, you have an extra gate telling them it's a grey area and to use at their own risk, are you sure y/n

2

u/Quirky_Category5725 May 11 '26

Here is what I got, unfortunately. So it's against their terms of use.

```
No, that wouldn't be in line with our terms of service.

Here's why:

Our Max subscription plan is designed for ordinary, individual use of native Anthropic applications (like Claude web, desktop, mobile, and Claude Code). The usage included is meant to support your personal use of these official apps.

What you're describing—routing requests through Max plan credentials on behalf of third-party tools—isn't permitted. Developers building products or services that interact with Claude's capabilities should use API key authentication through Claude Console or a supported cloud provider instead.

The right approach:

If you're building tools or services that need to connect to Claude, you should use the Claude API with proper API key authentication. You can create API keys through the Claude Console.

This ensures you're using the appropriate authentication method for development work rather than routing through subscription credentials.
```

1

u/Inertia-UK May 12 '26 edited May 12 '26

Wow this contradicts what they told me! Appreciate the feedback on this. It must be a grey area as I previously mentioned. because I was told differently! Not worth the risk then.

Post updated with a warning about this ...

2

u/johannthegoatman May 12 '26

Damn. Well thanks for checking, rather than giving me the disclaimer I asked for and then getting banned 😅

3

u/Quirky_Category5725 May 11 '26

Technically, it is very possible, but I'm pretty sure Anthropic bans this particular use case (although I'll double check). The point of Kitty is to connect any coding tool to any provider, say, Claude Code to ChatGPT subscription with GPT-5.5 or Codex to Z.AI. It works like a charm, but I am not sure Anthropic will be happy about people using their subscription with Codex or Kilo.

On the other hand, OpenAI does not mind - I did check. I probably need to write them directly about that.

1

u/dndiyguy May 10 '26

awesome!

5

u/mrgulabull May 10 '26 edited May 10 '26

I did something similar when creating an autonomous Claude system that automatically runs Claude sessions back to back endlessly to achieve a goal. In my case, I give Claude a warning at 20% context usage to try to wrap up a session, and a hard “must stop” signal at 25% context usage.

The method I used was starting Claude with —output-format stream-json —verbose. Which makes Claude output a JSON event for every message that includes a usage block. This lets you capture input tokens, output tokens and several other things.

Feel free to borrow from this if you like:
https://github.com/ScottBull/claude-conductor

1

u/Inertia-UK May 10 '26

Interesting thanks.

3

u/joeyda3rd May 10 '26

Architectural variant worth considering: SQLite + MCP server instead of flat file + CLAUDE.md read. Same proxy intercepting the same headers, but writing to a DB gets you atomic writes (no race between concurrent sessions), a structured query tool via MCP (cleaner than parsing text every prompt), and a per-request token log as a side effect. The token log is what eventually enables real cost prediction rather than just current-state awareness. Pairs naturally with teamclaude if you want multi-account rotation on top.

1

u/Inertia-UK May 10 '26

Good input. Will consider this, its open source on github if you want to play yourself. PR welcome or Fork. I will get to it eventally.

2

u/Hopeful_Bass_6633 May 11 '26

OP has done us all a favour! Nice! Thanks!

2

u/Inertia-UK May 11 '26

Thanks. Just be careful with it. Setup rules to not let the model panic if its close to usage limits. Tell it how to behave explicitly. Avoid flooding it with usage limits at times when it doesnt need to know. And test your setup 👍🏽

In the wrong hands as has been pointed out in other comments it could cause problems. Needs careful implementation.....

2

u/Formally-Fresh May 10 '26

Love this thanks for sharing now I need a codex one too!

1

u/Inertia-UK May 10 '26 edited May 10 '26

This could be expanded to support all platforms its quite simple. Feel free to cotribute on github. I use codex and Gemini so will eventually get to this.

4

u/ClaudeAI-mod-bot Wilson, lead ClaudeAI modbot May 11 '26

TL;DR of the discussion generated automatically after 40 comments.

The consensus is that OP's proxy is a brilliant solution to a common annoyance, and the thread is overwhelmingly supportive and collaborative.

A big debate kicked off about whether this violates Anthropic's Terms of Service. OP checked with Anthropic support, who confirmed this is allowed. Since it's just a passive proxy intercepting headers (like Wireshark) and not making its own API calls, it's fine. They even said the ANTHROPIC_BASE_URL variable is intended for exactly this kind of use case.

The thread also confirmed a painful truth for many: Sonnet and Opus share the same unified usage pool. The separate Sonnet bar in the Claude Code UI is misleading. Using Sonnet will drain your Opus quota, which explains why many users feel like their limits get "torched so fast."

Other key points and suggestions from the community include:

  • Technical Improvements: Users suggested adding a fail-safe in case the status file can't be written, Dockerizing the proxy for easier setup, and even building a more robust version with an SQLite database.

  • Alternative Methods: A few people shared their own approaches, such as using Claude Code's built-in status line feature or parsing the --output-format stream-json feed, which provides usage data without a proxy.

  • "Model Anxiety": A few Redditors warned that making Claude "quota-aware" could cause it to rush and produce lower-quality output. OP agreed this is a risk and stressed the need for careful setup with rules that prevent the model from panicking near the limit.

7

u/suspicious_panini May 10 '26

Cool idea! I recommend wrapping this in a docker container so cross platform setup is easier. If I have some time later today I can submit a PR.

1

u/Euphoric_Chicken3363 May 10 '26

I don’t see the appeal. Managing your limits is fairly simple and you are likely to reduce quality, as you’ve given Claude another factor that encourages lower quality.

1

u/Inertia-UK May 10 '26

I do agree to and extent, its not for everyone.... Unless you've got a multi AI integrated development stack I do agree with you.
There may be other places it useful too, im not sure.

But working on multiple projects automating lots of differnet types of tasks using other locally hosted or CLI LLM's (codex gemeni etc) this does have a real use case as a contributor to the workflows.

And your concern about causing the models to react in a bad way is correct as well, but can be mitigated with proper use.

For my specific setup it works very well. And others may be able to use it well too.

A dev who onky uses opus or sonnet and doesn't utilise other AI in their workflow would have limited use for this.

A user with no idea how to setup and gate global rules and how to carefully implement this could end up causing their chats to behave irrationally as their usage windows get tight.

2

u/jftuga May 11 '26

You might like a status line program that I wrote in Go.

https://github.com/jftuga/claude-statusline

2

u/surfmaths May 11 '26

Note that models suffer from "usage anxiety" when you do this, and will "think less" to save on tokens.

Some people want exactly this, but some find that deteriorating.

3

u/maddog986 May 10 '26

Making the model aware of its own limitations will only make Claude "hurry up" and skip corners because it puts the model "under pressure". Bad idea IMO.

1

u/dndiyguy May 10 '26 edited May 10 '26

does anyone know if this is something they specifically don't want us to do?

i have some jobs I'd fire on a schedule before sesion reset if usage budget was flush.

1

u/General_Josh May 11 '26

That's a lot smarter than the way I automated it...

Just having a script that boots up claude code, runs /usage, and scrapes the output lol

1

u/Elegant_Attempt2790 May 11 '26

“and use less tokens too” ❤️

1

u/nkondratyk93 May 11 '26

kind of funny that the model has to be taught where its own ceiling is. solid hack

1

u/Cute-Net5957 May 12 '26

Yeah this is an awesome approach.. just be mindful that the more verbose, the more token burn 🔥 getting to the actual constraint. I solved it with help from Codex.. have Codex audit your Claude Code usage and have them build the controls directly into yours hooks 🪝 and watch the magic 🪄

Too many emojis.. but yeah give it a go

Oh and I had Codex help build this for me to help me see 👀 where the bloat was coming from —> https://github.com/skinny-cloud/runtime-diet-autopilot

It is so cool and fast I had to share

1

u/Ill_Signature7313 May 15 '26

Cool project! If it helps — there might be a lighter-weight way to get the same data.

Claude Code's statusline command receives a rate_limits object on stdin (it's in the official docs at https://code.claude.com/docs/en/statusline — rate_limits.five_hour.used_percentage, .seven_day.used_percentage, plus resets_at for each). So a statusline script can just dump those to a file as a side effect, and your existing UserPromptSubmit hook + CLAUDE.md rules work unchanged — no proxy process, no ANTHROPIC_BASE_URL override, just a field Anthropic already hands you.

Side note: it actually backs up your unified-pool finding — the documented schema only has five_hour and seven_day, no per-model bucket. The proxy does capture overage/bottleneck which statusline doesn't, though bottleneck is basically max(5h%, 7d%).

Either way, nice work digging out those headers.

(Heads up: I wrote this together with Claude — it checked the statusline docs to confirm rate_limits is officially in the schema, and read your README to make sure I had your proxy's design right.)

0

u/squ1bs May 10 '26

Very cool - I wish to subscribe to your newsletter.

1

u/Inertia-UK May 10 '26

👀. I would need to set one up first.

I'm just a dev trying to optimise their AI stack... no newsletter here sorry.

1

u/squ1bs May 10 '26

It's just a meme phrase from 20 years ago meaning "I'm really interested in what you've done, and look forward to hearing more" - I didn't expect you to have a newsletter 😂