AutoAgent, a new open-source library, lets an AI engineer and optimise its own agent harness autonomously. In a 24-hour run, it reached #1 on SpreadsheetBench with 96.5% and achieved the top GPT-5 score on TerminalBench with 55.1%. The library automates the prompt-tuning loop that typically takes engineers dozens of iterations. https://www.marktechpost.com/2026/04/05/meet-autoagent-the-open-source-library-that-lets-an-ai-engineer-and-optimize-its-own-agent-harness-overnight/ #AIagent #AI #GenAI