xAI's Grok 4.5 Matches Top Coding Models at a Fraction of the Cost, Finds a Role as an 'Implementer' Agent

xAI released Grok 4.5 on July 8, 2026, positioning it as a coding- and agent-focused model that matches frontier benchmarks from rivals like Anthropic's Opus 4.8 and OpenAI's GPT-5.5 while undercutting them sharply on price. The company co-trained the model with Cursor to optimize it for real developer workflows, and early adopters are already slotting it into multi-agent setups as an execution engine.