Why MiMo-V2.5-Pro Changes the Open-Source Coding Agent Equation Every few months, an open-source model arrives that genuinely challenges the closed-source frontier. MiMo-V2.5-Pro, released by Xiaomi on April 22, 2026, is the latest to make that claim — and its benchmarks suggest it earns the comparison. The model sits at 57.2% on SWE-bench Pro , placing it above Claude Opus 4.6 (53.4%) and within half a point of GPT-5.4 (57.7%). On ClawEval, the agentic benchmark tied to the OpenClaw framework, it hits 63.8% Pass³ while consuming roughly 40–60% fewer tokens per trajectory than the frontier closed models. That combination matters for a specific reason: long-horizon agentic tasks are expensive. When a coding agent runs for 11 hours, makes 1,868 tool calls, and produces 8,000 lines of code, token cost is not a footnote — it's the budget line that determines whether the workflow is economically viable at all.…