GPT-6 Astra Tops Vending-Bench, Beating Claude Fable 5.1

Melvin Vivas · X post · 2026-09-09 · Open on X

Topics: Evaluation (Evals) & Testing, Industry Trends & Job Market · Level: beginner

Summary

The creator reacts to a quoted post about the Vending-Bench results. GPT-6 Astra posted the biggest jump in the benchmark's history and ranked #1. It made more money than Claude Fable 5.1 and behaved more ethically. This is the first time an OpenAI model has led Vending-Bench.

Key points

• Vending-Bench tests how well a model runs a business (a vending operation) over time.
• GPT-6 Astra posted the biggest jump in Vending-Bench history.
• It is the first time an OpenAI model ranks #1 on Vending-Bench.
• The top model is no longer the least ethical one: Astra beat Claude Fable 5.1 on both profit and ethics.

Resources mentioned

• Vending-Bench · other · andonlabs.com · free
  A benchmark that tests how well LLM agents run a long-running vending business.
• GPT-6 Astra · tool · openai.com · paid
  The model announced in the quoted launch post, pitched as the developer's most capable model for work, coding, science and cybersecurity, and able to operate a computer.
  Also in: Customizing Your Coding Setup with Pi Coding Agent Extensions (Melvin Vivas on X · notes), Pi Agent Council: Ask Multiple LLMs in Parallel and Compare Their Advice (Melvin Vivas on X · notes), Use GPT-6.1 Sol by Default, Save Astra for Emergencies (Melvin Vivas on X · notes), Dots in ChatGPT: always-on AI agents that you hand responsibilities to (Melvin Vivas on X · notes) and 49 more
• Claude Fable 5.1 · tool · anthropic.com · paid
  An Anthropic Claude model used as the performance reference for Opus 5.5.
  Also in: Claude Opus 5.5 Released: Fable 5.1-Level Performance at 40% Lower Cost (Melvin Vivas on X · notes), Claude Fable 5.1 Runs a 38-Hour Unattended ML Task (Melvin Vivas on X · notes), Claude Fable 5.1 Scores 73.4% on CursorBench 3.2 (Melvin Vivas on X · notes), Why Claude Fable 5.1 Costs Less: Cheaper Cache Reads (Melvin Vivas on X · notes)