Teams running long, unattended coding jobs can try it under MIT; Z.ai's eight-hour claim is worth testing yourself before relying on it.

Kenning's take

What it does

GLM-5.1 is a Z.ai text model designed for long tasks, which Z.ai says can work on its own for up to eight hours in one run. It targets planning, bug fixing and repeated refinement in software work. It is available through the Z.ai API, the GLM Coding Plan, OpenRouter, and as MIT-licensed open weights.

  • Long autonomous runs of up to 8 hours
  • Planning, execution and iterative refinement
  • Improved tool use over long tasks
  • Available on OpenRouter
  • MIT open-source licence

Who it suits. Developers who run long, unattended coding agent jobs.

Key facts

Category
AI models
Made by
Z.ai (Zhipu AI)
Based in
China
Released
7 April 2026
How to get it
Z.ai API (model glm-5.1), GLM Coding Plan, OpenRouter, or self-hosted from open weights
Works on
API, open weights (Hugging Face)
In the UK
Yes
API price
$1.40 per million input tokens, $4.40 per million output tokens

Pricing

PlanPriceBilled
GLM Coding Plan$from 18month

source

FAQ

When was GLM-5.1 released?

Z.ai listed GLM-5.1 in its release notes on 7 April 2026.

How long can GLM-5.1 work on a task?

Z.ai says up to eight hours in a single run.

Facts from the maker's own pages and the sources listed. Checked 2026-10-11.