Meta confirms it will promote the Harness tool, and an open-source model is also in the works

According to DynaBeat monitoring, Meta's Chief AI Officer, Alexandr Wang, stated at YC Startup School 2026 that the company will launch its proprietary Harness tool and continue to release open-source models.

Harness is an Agent runtime framework wrapped around the model, such as Claude Code. It is responsible for invoking tools, reading/writing files, and managing the context to enable the model to complete complex tasks seamlessly.

In April of this year, Meta had already planned to open source some of its new models.