xAI launches Grok 4 with native tool use and a multi-agent Heavy edition
xAI's Grok 4 adds tool calling and reasoning inside the model itself, alongside Grok 4 Heavy, a multi-agent edition built for harder problems.
xAI has announced Grok 4, the company’s new model generation. As described by xAI, Grok 4 adds native tool use together with reasoning capability, and ships alongside Grok 4 Heavy, a multi-agent edition for harder tasks.
Native tool use means the model is trained to call external tools on its own when needed, rather than waiting for an intermediary layer to arrange each step. This lets the model look up data, run calculations or connect to other systems within the same processing flow. The Heavy edition goes further by organising several agents to take part together, suited to problems that need to be broken down and coordinated.
For businesses, this approach ties into workflows with many steps and many data sources, where a single answer is often not enough. A model that calls tools itself can shorten the manual plumbing. The announcement gave no figures on performance, cost or usage limits.
What to keep in mind is that a model calling tools on its own demands tight access control. Engineering teams should limit which tools may be called, which data may be read, and how each call is logged for traceability. With multi-agent configurations, cost and latency can grow with the number of steps.
Source: x.ai
