xAI Launches Composer 2.5 in Grok Build for Agentic Coding
xAI
xAI released Composer 2.5 inside Grok Build on June 1, 2026, a fast agentic coding model built on the open-source Moonshot Kimi K2.5 checkpoint and trained with 25 times more synthetic tasks than its predecessor. Available at build.grok.com at $0.50 per million input tokens, it excels at long-running agentic tasks, JSON, tool use, and complex instruction-following.
Why it matters
Composer 2.5 significantly undercuts comparable agentic coding models on price while matching frontier performance, and its Kimi K2.5 foundation highlights the increasing role of open-weight Chinese models in Western AI products.
Importance: 3/5
Official xAI announcement plus primary-media coverage; notable for Kimi K2.5 foundation and sub-cent pricing.
Sources
official
Composer 2.5 — xAI