CLI 5.6.0

Runtime-local model lists offer the newest models: GPT-6 Sol and GPT-6 Luna for Codex, and Opus 5, Opus 5.5, Sonnet 5.5 and Fable 5.1 for Claude Code. GPT-5.4, GPT-5.4 Mini and GPT-5.2, which Codex itself retired, are no longer offered.