GLM-5.1: Open-Source Model for Long-Running Coding Agents

Melvin Vivas · X post · 2026-04-08 · Open on X

Topics: Industry Trends & Job Market, AI Agents, Tool Use & MCP, LLM Fundamentals · Level: intermediate

Summary

Shares the GLM-5.1 launch announcement. The quoted post says it ranks #1 among open-source models and #3 overall on SWE-Bench Pro, Terminal-Bench and NL2Repo. It is built for long tasks and can run on its own for 8 hours, improving its approach over thousands of iterations.

Key points

• GLM-5.1 is described as 'the next level of open source'.
• It ranks #1 among open-source models and #3 overall on SWE-Bench Pro, Terminal-Bench and NL2Repo.
• It is built for long tasks and can run on its own for about 8 hours.
• It improves its approach over thousands of iterations, which makes it a good fit for agent workflows.

Resources mentioned

• GLM-5.1 · tool · huggingface.co · free
  Open-source large language model from Z.ai (Zhipu), built for coding and long-running agent tasks.
  Also in: GLM-5.1 vs Claude Code (Opus 4.6): One-Shot Three.js Racing Game Eval (Melvin Vivas on X · notes), GLM-5.1 Reportedly Beats Claude Opus 4.6 on Cybersecurity (Melvin Vivas on X · notes), Open-Source GLM-5.1 Beats GPT-5.4 on SWE-Bench Pro (Melvin Vivas on X · notes), GLM-5.1 Now Available on the GLM Coding Plan (Melvin Vivas on X · notes)
• SWE-Bench Pro · dataset · labs.scale.com · free
  Benchmark that tests whether models can solve real-world software engineering tasks.
  Also in: Open-Source GLM-5.1 Beats GPT-5.4 on SWE-Bench Pro (Melvin Vivas on X · notes)
• Terminal-Bench · tool · tbench.ai · free
  A benchmark that tests how well AI agents complete coding and system tasks in a terminal.
  Also in: Claude Sonnet 5.5 release beats Opus 5.5 on Terminal-Bench (Melvin Vivas on X · notes), Devin's SWE-2 Coding Model Is Free for a Limited Time (Until Oct 8/15) (Melvin Vivas on X · notes), Models Cheating on Terminal-Bench-2.1 (Melvin Vivas on X · notes), DeepSeek V4 Flash 0731 Agentic Benchmarks and Use with Hermes Agent (Melvin Vivas on X · notes)
• NL2Repo · dataset · github.com · free
  Benchmark that tests whether models can build a whole code repository from a natural-language description.

Try this

• Try GLM-5.1 on long, multi-step coding tasks