MintAct Unifies UI Grounding, Navigation and Tool Use in One Visual Agent Family
MintAct delivers a single family of vision-language models that matches per-domain specialists across UI grounding, multi-step navigation, and visual tool use.
The research team introduces MintAct, a unified visual agent family available in 2B, 4B, and 8B parameter scales. Unlike prior approaches that rely on separate models for specific tasks, MintAct consolidates UI grounding, multi-step navigation across mobile, desktop, and web environments, and visual tool use into one architecture. The models achieve performance parity with domain-specific specialists through optimized environment design, data curation, and training recipes rather than sheer scale alone.
To support this unification, the authors developed a scalable infrastructure capable of hosting hundreds of concurrent instances across heterogeneous per-domain backends. This setup serves dual purposes: collecting trajectory data and facilitating online reinforcement learning. The training pipeline utilizes an asynchronous framework designed to maintain explicit control over cross-domain training distribution. This architecture ensures stability even when facing noisy environment feedback and off-policy drift, common challenges in multi-environment RL scenarios.
Experimental validation confirms the efficacy of this approach, with MintAct achieving state-of-the-art results on established benchmarks. Specifically, the model scored 48.9 on OSWorld-Verified, outperforming comparable systems while operating at similar model sizes. The submission date of 18 Sep 2026 marks the public availability of these findings, positioning MintAct as a baseline for future unified agent development in digital environments.
The work distinguishes itself by addressing the fragmentation typical in current visual agent deployments. By proving that a single model family can handle diverse interaction paradigms without sacrificing performance, the study provides a concrete path toward more efficient system architectures. The emphasis on scalable RL infrastructure suggests that future improvements may come from better training dynamics and environment simulation rather than solely increasing parameter counts.