The lab behind GLM
Z.ai, formerly Zhipu AI
Z.ai is the Beijing AI lab that builds the GLM family of models, one of the most openly licensed frontier model lines in the world. It also ran the anonymous 'Ox Alpha' stealth model this site is built around. Here is who they are, what they make, and how to use it.
Z.ai (the international brand of Zhipu AI) was founded in 2019 as a commercial spin-out of Tsinghua University's KEG lab. It is one of China's leading large-model labs, and unusually open with its weights: its recent GLM models ship under the permissive MIT license, free to self-host.
The company adopted the Z.ai brand in 2025 and listed on the Hong Kong Stock Exchange in January 2026. It is also on the US Commerce Department's Entity List (a factual export-control status covered below), which is worth weighing for regulated use, alongside the fact that its models are openly downloadable. Last verified October 4, 2026.
2019
Founded
Beijing
Headquarters
MIT
GLM-4.5 / 4.6 license
2026
Hong Kong IPO
- Company
- Z.ai, formerly Zhipu AI (legal entity: Beijing Zhipu Huazhang Technology Co., Ltd.).source Reported
- Founded
- 2019, as a commercial spin-out of Tsinghua University's KEG (Knowledge Engineering Group) lab.source Reported
- Headquarters
- Beijing, China.source Reported
- Brand
- Adopted 'Z.ai' as its international brand in July 2025; the domestic entity remains Zhipu.source Reported
- Models
- The GLM (General Language Model) family: ChatGLM, GLM-4, the open-weight GLM-4.5 to GLM-4.7, and the GLM-5 generation (GLM-5, GLM-5.1, GLM-5.2 and the current GLM-5.3).source Confirmed
- Funding
- Roughly $1.5B raised since founding; investors include Alibaba, Tencent, Ant Group, Meituan, Xiaomi, HongShan, and Prosperity7 Ventures.source Reported
- Public listing
- Listed on the Hong Kong Stock Exchange in January 2026, among the first of China's large-model companies to go public.source Reported
- API
- An OpenAI-compatible API at api.z.ai (base https://api.z.ai/api/paas/v4/), so most OpenAI SDKs work by swapping the base URL.source Confirmed
- US Entity List
- Beijing Zhipu Huazhang was added to the US Commerce Department (BIS) Entity List in January 2025; the company publicly disputed the designation.source Confirmed
The models
The GLM family
Z.ai's models all belong to the GLM (General Language Model) line: from the early open ChatGLM models, through the MIT-licensed GLM-4.5 and GLM-4.6, to the current GLM-5.3, whose Flash variant ran as Ox Alpha. The full family, compared, is on the GLM page.
GLM Coding Plan
Z.ai's coding subscription
Z.ai's best-known product beside the models themselves is the GLM Coding Plan: a monthly subscription that pays for GLM-5.3 and GLM-5.3-Flash inside the coding agents and IDEs you already run, instead of paying per token.
It comes in three tiers (Lite, Pro and Max), each a credit allowance with a rolling 5-hour limit and a weekly limit, and usage outside Z.ai's weekday peak hours costs half the credits. It works inside 20+ coding tools. Z.ai pitches it as saving up to 92% against its own pay-as-you-go API; our guide works out what each tier is really worth, and when paying per token is cheaper.
The API
OpenAI-compatible, at api.z.ai
Z.ai exposes an OpenAI-compatible API (base https://api.z.ai/api/paas/v4/), so most OpenAI SDKs work by pointing the base URL at Z.ai.
Stealth previews
Pony Alpha, then Ox Alpha
Z.ai has a pattern of previewing new models anonymously. It ran GLM-5 as “Pony Alpha”, then GLM-5.3 Flash as “Ox Alpha”: a free, unbranded model developers wired into their agents before the community fingerprinted it as Z.ai's. This site is the case file on that hunt, independent of Z.ai.
Export controls
The Entity List, stated plainly
In January 2025, Beijing Zhipu Huazhang Technology (Zhipu AI) was added to the US Commerce Department's (BIS) Entity List, restricting certain US exports to the company without a license. The stated US rationale was concern about support for China's military modernization; Zhipu publicly disputed the designation.
Try it
Try a Z.ai model in your browser
You can try GLM-5.3 Flash without a Z.ai account: our homepage points to a browser studio where it runs, and the API guide shows how to call it from code.
FAQ
Straight answers about Z.ai
What is Z.ai?
Is Z.ai the same as Zhipu AI?
What models does Z.ai make?
What is the GLM Coding Plan?
Is Z.ai's API OpenAI-compatible?
Is Z.ai on the US Entity List?
What were Ox Alpha and Pony Alpha?
Build with a GLM model
You have seen who makes GLM and how open it is. The next step is to build something real with it, without wiring up any of the infrastructure yourself.