Anthropic blocks third-party use of Claude Code subscriptions

For folks not following the drama: Anthropic's $200/month subscription for Claude Code is much cheaper than Anthropic's pay-as-you-go API. In a month of Claude Code, it's easy to use so many LLM tokens that it would have cost you more than $1,000 if you'd paid via the API.

Why is Anthropic offering such favorable pricing to subscribers? I dunno. But they really want you to use the Claude Code™ CLI with that subscription, not the open-source OpenCode CLI. They want OpenCode users to pay API prices, which could be 5x or more.

So, of course, OpenCode has implemented a workaround, so that folks paying "only" $200/month can use their preferred OpenCode CLI at Anthropic's all-you-can-eat token buffet.

https://github.com/anomalyco/opencode/issues/7410#issuecomme...

Everything about this is ridiculous, and it's all Anthropic's fault. Anthropic shouldn't have an all-you-can-eat plan for $200 when their pay-as-you-go plan would cost more than $1,000+ for comparable usage. Their subscription plans should just sell you API credits at, like, 20% off.

More importantly, Anthropic should have open sourced their Claude Code CLI a year ago. (They can and should just open source it now.)

This is an unusual L for Anthropic. The unfortunate truth is that the engineering in opencode is so far ahead of Claude Code. Obviously, CC is a great tool, but that's more about the magic of the model than the engineering of the CLI.

The opencode team[^1][^2] built an entire custom TUI backend that supports a good subset of HTML/CSS and the TypeScript ecosystem (i.e. not tied to Opencode, a generic TUI renderer). Then, they built the product as a client/server, so you can use the agent part of it for whatever you want, separate from the TUI. And THEN, since they implemented the TUI as a generic client, they could also build a web view and desktop view over the same server.

It also doesn't flicker at 30 FPS whenever it spawns a subagent.

That's just the tip of the iceberg. There are so many QoL features in opencode that put CC to shame. Again, CC is a magical tool, but the actual nuts and bolts engineering of it is pretty damning for "LLMs will write all of our code soon". I'm sorry, but I'm a decent-systems-programmer-but-terminal-moron and I cranked out a raymarched 3D renderer in the terminal for a Claude Wrapped[^] in a weekend that...doesn't flicker. I don't mean that in a look-at-me way. I mean that in a "a mid-tier systems programmer isn't making these mistakes" kind of way.

Anyway, this is embarrassing for Anthropic. I get that opencode shouldn't have been authenticating this way. I'm not saying what they are doing is a rug pull, or immoral. But there's a reason people use this tool instead of your first party one. Maybe let those world class systems designers who created the runtime that powers opencode get their hands on your TUI before nicking something that is an objectively better product.

[^1] https://github.com/anomalyco/opentui

[^2] From my loose following of the development, not a monolith, and the person mostly responsible for the TUI framework is https://x.com/kmdrfx

[^3] https://spader.zone/wrapped/

This will piss a lot of people off, and seems like a strange move. I get that this was always a hack and against the ToS. But I've been paying Anthropic money every month to do exactly what I would have done with Claude Code, but in another harness that I like better. All they've achieved here is that I am no longer giving them money. Their per-token pricing is really expensive compared to OpenAI, and I like the results from the OpenAI models better too, they're just very slow.

Here's a good benchmark from the brokk team showing the performance per dollar, GPT-5.1 is around half the price of Opus 4.5 for the same performance, it just takes twice as long.

https://brokk.ai/power-ranking?dataset=openround&models=flas...

So as of today, my money is going to OpenAI instead of Anthropic. They probably don't care though, I suspect that not many users are sufficiently keen on alternative harnesses to make a difference to their finances. But by the same token (ha ha), why enforce this? I don't understand why it's so important to them that I'm using Claude Code instead of something else.

This headline is misleading. EDIT: Or rather was, at it has now been edited to be accurate.

You can still bring your own Anthropic API key and use Claude in OpenCode.

What you can no longer do is reverse engineer undocumented Anthropic APIs and spoof being a Claude Code client to use an OAuth token from a subscription-based Anthropic account.

This really sucks for people who want a thriving competitive market of open source harnesses since BYOK API tokens mean paying a substantial premium to use anything but Anthropic's official clients.

But it's hard to say it's surprising or a scandal, or anything terribly different from what tons of other companies have done in the past. I'd personally advise people to expect everything about using frontier coding models becoming much more pay-to-play.

The API is not banned only using the Claude Code subscription is

I actually tried this several months back to do a regular API request using the CC subscription token and it gave the same error message

So this software must have been pretending to be Claude Code in order to get around that

A Claude Code subscription should not work with other software, I think this is totally fair

Engineer working on Amp here.

I'm very surprised that it took them this long to crack down on it. It's been against the terms of service from the start. When I asked them back in March last year whether individuals can use the higher rate limits that come with the Claude Code subscription in other applications, that was also a no.

Question is: what changed? New founding round coming up, end of fiscal year, planning for IPO? Do they have to cut losses?

Because the other surprise here is that apparently most people don't know the true cost of tokens and how much money Anthropic is losing with power users of Claude Code.

FWIW this isn’t new, using a Claude/Max subscription auth token as a general-purpose “API key” has been known (and blocked) for ages. OpenCode basically had to impersonate the official Claude Code client to make that work, and it always felt like a loophole that would get patched eventually.

This is exactly why (when OpenCode and Charm/Crush started diverging) Charm chose not to support “use your Claude subscription” auth and went in a different direction (BYOK / multi-provider / etc). They didn’t want to build a product on top of a fragile, unofficial auth path.

And I think there’s a privacy/policy reason tightening this now too: the recent Claude Code update (2.1-ish) pops a “Help improve Claude” prompt in the terminal. If you turn that ON, retention jumps from 30 days to up to 5 years for new/resumed chats/coding sessions (and data can be used for model improvement). If you keep it OFF, you stay on the default 30-day retention. You can also delete data anytime in settings. That consent + retention toggle is hard to enforce cleanly if you’re not in an official client flow, so it makes sense they’re drawing a harder line.

I know this will sound strange, but SOTA model companies will eventually allow subscription based usage through third-party tools. For any usage whatsoever.

Models are pretty much democratized. I use Claude Code and opencode and I get more work done these days with GLM or Grok Code (using opencode). Z.ai (GLM) subscription is so worth it.

Also, mixing models, small and large ones, is the way to go. Different models from different providers. This is not like cloud infra where you need to plan the infra use. Models are pretty much text in, text out (let's say for text only models). The minor differences in API are easy to work with.

The fix has been merged in https://github.com/anomalyco/opencode-anthropic-auth/pull/11, and PR https://github.com/anomalyco/opencode/pull/7432 is open to bump the version.

Until it's released, here's a workaround:

1. git clone https://github.com/anomalyco/opencode-anthropic-auth.git

2. Add to ~/.config/opencode/opencode.json: "plugin": ["file:///path/to/opencode-anthropic-auth/index.mjs"]

3. Run: OPENCODE_DISABLE_DEFAULT_PLUGINS=true opencode

I’m not surprised they closed the loophole, it always felt a little hacky using an Anthropic monthly sub as an API with a spoofed prompt (“You are Claude Code, Anthropic's official CLI for Claude”) with OpenCode.

Google will probably close off their Antigravity models to 3P tools as well.

Lots of arguing about semantics of what the subscription is actually intended for.

Claude Code, as a coding assistant, isn't even mediocre, it's kind of crap. The reason it's at all good is because of the model underneath - there's tons of free and open agent tools that are far better than Claude Code. Regardless of what they say you're paying the subscription for, the truth is the only thing of value to developers is the underlying AI and API.

I can only think of few reasons why they'd do this: 1. Their Claude Code tool is not simply an agent assistant - perhaps it's feeding data for model training purposes, or something of the sorts where they gain value from it. 2. They don't want developers to use competitor models in any capacity. 3. They're offloading processing or doing local context work to drive down the API usage locally, making the usage minimal. This is very unlikely.

I currently use Opus 4.5 for architecting, which then feeds into Gemini 3 Flash with medium reasoning for coding. It's only a matter of time before Google competes with Opus 4.5, and when they do, I won't have any loyalty to Anthropic.

And it already has a workaround. https://github.com/anomalyco/opencode/issues/7410#issuecomme...

I really don't understand why they thought this is a good idea. I mean I know why they wish to do this, but it's obviously not going to last.

Here's how to get a refund on the website (all automated):

1. Profile Icon -> Get Help

2. Send us a Message

3. Click 'Refund'

Big corpos only talk money, so it's the best you could do in this situation.

If you can't refund, and need to wait till sub runs out after cancelling, go to the OpenCode repo and rename your tools so they start with capital letters. That'll work around it. They just match on lowercase tool names of standard tools.

Cancelled my claude subscription over it. Opencode is miles ahead of any coding tools. Will stick to using it rather than claude. Other models / other ways to access claude exists.

Funnily enough, I didn't know about opencode and will now test it out and likely use it instead.

Improve your client so people prefer it? Nah.

Try to force people to use your client by subsidizing it? Now that's what I'm talking about.

As others said, why not just run a bunch of agents on Claude Code to surpass Opencode? I'm sure that's easy with their unlimited tokens!

Ugh, well at least this was the nudge I needed to cancel my Claude Pro subscription... I've already had a bad taste in my mouth watching the rate limits on the plan get worse and worse since I first subscribed and I have a few other subscriptions to fall back on while I've been evaluating different options. I literally never use the regular Claude Chat web UI either, that's pretty much 100% Gemini since I get it via my Google One plan.

OpenCode makes me feel a lot better knowing that my workflow isn't completely dependent on single vendor lock-in, and I generally prefer the UX to Claude Code anyway.

Meanwhile, OpenAI co-signs https://github.com/steipete/oracle which lets you use your ChatGPT subscription to gain programmatic/agentic access to 5.2 Pro via automating browser access to the web frontend. Karpathy and other leaders have praised this feature on X.

If that is indeed so welcome, imagine what else you could script via their website to get around Codex rate limits or other such things.

After all what coud be so different about this than what browsers like Atlas do already

This appears to be a part of a crackdown on third-party clients using Claude Code's credentials/subscriptions but not through Claude Code.

Not surprising as this type of credential reuse is always a gray area, but weird Anthropic deployed it on a Thursday night without any warning as the inevitable shitstorm would be very predictable.

btw, Amp just announced Opus 4.5 is now supported in their free tier: https://ampcode.com/news/amp-free-frontier. I've been using it a ton and it's a super nice cli. It has ads, but they are fairly non-intrusive

This reminds me of when Anthropic cut first-party access to Claude models in Windsurf as they were about to be acquired by Google.

https://www.reddit.com/r/ChatGPTCoding/comments/1l2y2kh/anth...

Switched to the z.ai coding plan, and used the GLM 4.7 model for a few complex changes since posting this, and it works really well.

I don't think I will renew Anthropic, the open models have reached an inflection point.

fork OC and use anthropics agent SDK that allows you to build on top of your subscription

The Agent SDK can piggyback on your existing Claude Code authentication

https://platform.claude.com/docs/en/agent-sdk/quickstart

they didn't even ban non claude code clients they just banned certain tool names that opencode uses...

https://github.com/anomalyco/opencode/issues/7410#issuecomme...

Wow, i sat down to do a little bit of late night coding and ended up running into this nightmare. Just canceled my anthropic subscription and started paying for opencode zen. Unfortunately opencode is enough of a better product i will indeed pay 10 times the price to use it.

OpenCode brought this on themselves and their users. Plugging Claude Max subscriptions into other agents has been against the terms of service basically since the start and I imagine Anthropic must have issued plenty of warnings here that were ignored. They wouldn’t do this unless they really had to. If folks are mad about being rugged, blame OpenCode for misleading their users when they’ve long known this day was coming. Brilliant cynical strategy though to exploit soft enforcement for growth and lay the blame at the company that provided them cheap tokens.

For anyone coming looking for a solution; I peeked around the OC repository, and a few PRs got merged in. Add this to $HOME/.config/opencode/opencode.json: plugin = ["opencode-anthropic-auth"]

That is, if that's not pulled in to latest OC by the time I post this. Not sure what the release cycle is for builtin plugins like that, but by force specifying it it definitely pulls master which has a fix.

https://opencode.ai/docs/plugins/

I know this is somewhat unreasonable but watching "devs" unable to work because "faceless corp 1007" cut their access definitely has a level of schadenfreude to it.

This situation feels like a +1 for Agent Client Protocol (ACP) [1].

In ACP, you auth directly to the underlying agent (eg Claude Code SDK) rather than a third-party tool (eg OpenCode) that then calls an inference endpoint on your behalf. If you're logged into Claude Code, you're already logged into Claude Code through any ACP client.

[1] https://agentclientprotocol.com/overview/agents

The TOS, which is a contract of adhesion for consumer-facing products, does not really matter that much in my opinion since "we have to lock you in to our specific interface on our public offering" is not a cognizable interest. SCOTUS is also very clear in requiring actual damages (in incremental harms) to establish a CFAA violation. At any rate, opencode is essentially providing equitable estoppel as a service by being open and popular - cannot go after me without first dealing with the "unionized" project (last words)! I don't think they get to conflate the issues of alternative interface dispute and their intentional pricing strategy losing money on heavy users.

Of course, they are banning for financial economic interests, not nominal alleged contractual violations, so Anthropic is not sympathetic.

// NOT LEGAL ADVICE

Obviously, I think it can make sense to Anthropic since opencode users likely disproportionately cost them money with little lock-in - you can switch the moment a comparable model is available elsewhere. It does not (necessarily) mean there are any legal or ethical issues barring us from continuously using the built-in opencode OAuth though.

Not strictly related, but since Copilot could be the next to violate the TOS, I've asked for an official response here: https://github.com/orgs/community/discussions/183809. If someone can help raise this question, it's more than welcome.

Why act like it’s a mystery when the Claude Code repo clearly explains:

> When you use Claude Code, we collect feedback, which includes usage data (such as code acceptance or rejections), associated conversation data, and user feedback submitted via the /bug command.

They subsidize Claude Code because it gives them your codebase and chat history

inference costs nothing in comparison to training (you have so many requests in parallel at their scale), for inference they should be profitable even when you drain whole weekly quota every week

but of course they have to pay for training too.

this looks like short sighted money grab (do they need it?), that trade short term profit for trust and customer base (again) as people will cancel their unusable subscriptions.

changing model family when you have instructions tuned for for one of them is tricky and takes long time so people will stick to one of them for some time, but with API pricing you quickly start looking for alternatives and openai gpt-5 family is also fine for coding when you spend some time tuning it.

another pain is switching your agent software, moving from CC to codex is more painful than just picking different model in things like OC, this is plausible argument why they are doing this.

This makes total sense to me. Limiting the usage to their tooling means they can place reasonable limits on usage by controlling how the client interacts with the LLM and making those calls as efficient as possible. The current state of things didn't really feel sustainable.

Woke up and everything is on Fire, I thought opencode had some bug coz it updated itself this morning, but realised its claude who blocked third party clients :( L for Anthropic indeed, opencode had wayyy better experience than claude code.

Genuine question, as someone who never used Claude Code, but used OpenCode/Aider/GeminiCli - as many here say Opencode is better, mind sharing why (from end user perspective)?

I was thinking to try Claude Code later and may reconsider doing so.

I've been (adding an OpenCode feature that allows the LLM to edit its own context)[1] and trying to debug an issue with the Anthropic API because I'm calling it with missing fields that it expects. I hope my multiple erronious API calls aren't what triggered this decision

[1]: https://github.com/Vibecodelicious/opencode/tree/surgical_co...

Unsure of the other competition, but I can vouch for synthetic.new's subscription for GLM (+ other open models). Note quite as accurate as Anthropic's models but good enough for basically everything I do.

A crucial context is that this "block" is resolved (for now) via bumping version numbers. It is almost as if Anthropic deployed this to test the water on community reaction... Right now it is trivial to fingerprint opencode users without deep inspection into the conversations (privacy conerns), but Anthropic is not doing that.

https://github.com/anomalyco/opencode/commit/5e0125b78c8da09...

Claude Code subscription is called for a reason, it's not Anthropic API subscription…

And Claude Code Pro is also similar to ChatGPT Pro, being used in a TUI does not mean it is equivalent to an API.