xAI AI Updates: May 15, 2026

1. xAI launches Grok Build, an agentic coding CLI

xAI. xAI introduced Grok Build, its first coding agent, a terminal-native agentic CLI for professional software engineers, positioned against Anthropic’s Claude Code. The beta runs on Grok 4.3 (2M token context, 16-agent Heavy architecture), supports a plan-review-approve workflow with clean diffs, parallel subagents, git worktree integration, MCP servers, AGENTS.md, headless CI/CD mode, and full Agent Client Protocol support. Initially limited to SuperGrok Heavy ($300/month), with a new SuperHeavy tier offered at $99/month for the first six months. Accessible at build.grok.com via one-command curl install. Source

2. xAI retires eight Grok models on May 15, auto-redirects to grok-4.3

xAI. xAI’s official migration notice schedules retirement of eight older Grok models, including grok-imagine-image-pro, at 12:00 PM PT on May 15, 2026. Requests to retired slugs will auto-redirect to grok-4.3 (1M token context, four reasoning-effort levels), and stragglers will be billed at grok-4.3 rates ($1.25/M input, $2.50/M output), which may meaningfully change cost profiles. xAI advises explicitly switching to grok-4.3 before the cutover, and migrating image jobs to grok-imagine-image-quality. Source