Z.ai API for Top Open-Source GLM Coding

The Z.ai API gives developers programmatic access to the GLM series of large language models built by Z.ai, the company also known as Zhipu AI. GLM stands for General Language Model and spans releases from GLM-4.6 to the GLM-5.1 flagship, tuned for coding, agentic workflows, and bilingual Chinese and English production use. On Atlas Cloud you reach the full lineup through one OpenAI-compatible endpoint.

Atlas Cloud hosts the GLM series from GLM-4.6 up to the GLM-5.1 flagship, with GLM-4.7 and GLM-5 in between. Lighter tiers handle high-volume everyday tasks at lower cost, while GLM-5.1 targets the most demanding coding and agentic work. Every model runs pay-as-you-go through the same key.

Yes. GLM open weights, including GLM-5.1, are released under the MIT license, which permits commercial use, fine-tuning, and redistribution without restriction. If you would rather skip infrastructure overhead, Atlas Cloud serves the same models by API for managed access instead of self-hosting.

Point your existing OpenAI SDK at the Atlas Cloud base URL, set your key, and pass the GLM model name you want. Because the Z.ai API is OpenAI-compatible, most projects migrate by changing only the base URL and model string, and the models plug directly into agent tools such as Claude Code, Cline, and Roo Code. Start building today.

Both Chinese and English are first-class for GLM, which is trained for strong proficiency in each. Prompt in either language and you get consistent quality back, which makes the lineup practical for teams serving Chinese and international users from a single model rather than maintaining separate stacks.

GLM-4.6 through GLM-5.1 support a 200K token context window, enough to hold large codebases, long documents, or extended agent traces in a single request. Should your workflow produce long outputs, the same window covers big code files and multi-step execution logs without early truncation.

GLM-5.1 topped SWE-Bench Pro with a score of 58.4 in April 2026, placing it among the strongest open-source models for real-world coding. It also supports continuous autonomous execution for up to eight hours on a single task, running planning, iteration, and delivery in one loop, which suits long-horizon agent workflows in environments like Claude Code.

Every GLM model on the Z.ai API runs on transparent pay-as-you-go pricing, billed per token with no subscription or monthly commitment. Input and output tokens are metered separately, and lighter tiers such as GLM-4.7 cost less per token than the GLM-5.1 flagship, so you can match model choice to budget. Check the current per-token rate on each model card in Atlas Cloud.