MiniMax M3 Tool Calling: Build an Agentic Loop in Python

MiniMax shipped MiniMax-M3 on June 1, 2026, and it has been the loudest release on the open-weight side of AI all week. It is the first open model to bundle three frontier capabilities at once: a 1,000,000-token context window (powered by its MiniMax Sparse Attention architecture), native multimodality, and genuinely strong agentic coding and tool use. On the BrowseComp browsing benchmark MiniMax reports M3 scoring 83.5, ahead of Claude Opus 4.7 at 79.3.

The part that matters for builders is the last one. M3 was trained to drive long-horizon agent loops: decide what tool to call, read the result, decide the next step, and keep going until the job is done. MiniMax demoed it running unattended for ~12 hours to reproduce an ICLR paper and ~24 hours to optimize a CUDA kernel through 1,959 tool calls. You do not need a 24-hour job to benefit from that. The same loop powers a customer-support agent, a data lookup bot, or a code fixer.