And no, there is no way to buy it. The website is chatglm.cn for subscription. But you need a Chinese phone number, Chinese bank account (Alipay, WeChat Pay).
469 Yuan = 69 $.
I got a Codex membership when GPT-5.4 launched and was getting by well enough for a while. Then I started using Claude and GLM 5.1, and my production quality improved significantly. Now that I’ve hit the limits on both, I’m forced to go back to GPT-5.4, and honestly, it’s infuriating. I have no idea how I put up with this for a month. It constantly breaks one thing while trying to fix another. It never delivers results that make you say 'great'. It’s always just 'mediocre' at best. And that’s if you’re lucky. And the debugging process is a total disaster. It breaks something, and then you can never get it to fix what it broke. I’m never, ever considering paying for Codex again. Just look at the Chinese OSS models built with 1/1000th of the investment. It makes GPT's performance look like a total joke.