Codex CLI 0.124.0: Reasoning Controls, Multi-Environment Support

TL;DR

• TUI now has keyboard shortcuts to adjust reasoning level on the fly
• App-server sessions support multiple environments and per-turn working directory selection
• Stable hooks with inline config and MCP tool observation
• Amazon Bedrock support now includes AWS SigV4 auth

New

• Reasoning level shortcuts — Alt+, lowers reasoning, Alt+. raises it; model upgrades now reset reasoning to the new model's default instead of carrying stale settings
• Multi-environment app-server sessions — choose environment and working directory per turn, making multi-workspace and remote setups easier to target
• Amazon Bedrock with AWS SigV4 — first-class support for OpenAI-compatible providers with AWS credential-based auth
• Remote plugin marketplace improvements — list and read plugins directly with more reliable detail lookups and larger result pages
• Stable hooks — now configurable inline in config.toml and requirements.toml; observe MCP tools, apply_patch edits, and long-running Bash sessions
• Fast service tier default — eligible ChatGPT plans now default to Fast unless you explicitly opt out

Fixed

• Cloudflare cookies now preserved across approved ChatGPT hosts, reducing auth breakage in HTTP-backed flows
• Remote app-server reliability — websocket events keep draining under load and shutdown no longer fails when the remote worker exits during cleanup
• Permission-mode drift fixed so /permissions changes survive side conversations and MCP approval handling reflects Full Access state correctly
• wait_agent now returns promptly when mailbox work is already queued instead of waiting for fresh notification or timing out
• Local stdio MCP launches for relative commands without explicit cwd now use fallback path resolution consistent with CLI behavior
• Startup edge cases — unknown feature requirements warn instead of aborting, and cloud-requirements errors are clearer about what failed

Update: npm install -g @openai/codex@0.124.0 or check the full release on GitHub

Source: Codex