In May 2026, OpenAI published its internal Codex deployment practices: sandboxes define technical boundaries, approval policies determine when to pause, Auto-review delegates approval decisions to a sub-agent instead of a human, and Managed configuration lets enterprise admins enforce policies top-down. The core philosophy: zero friction for low-risk actions, mandatory review for high-risk ones.
Spin up a local OpenAI-compatible endpoint at localhost:20128 that automatically routes requests from Claude Code / Cursor / Cline / Codex / Copilot through a Subscription → Cheap → Free 3-tier fallback to 40+ providers. Built-in RTK compresses tool_result (saving 20–40% input tokens), Caveman mode compresses output, OAuth auto-refresh, multi-account round-robin — install with npm install -g 9router and two commands.
Anthropic builds an extension, OpenAI builds its own browser, Google welds AI directly into Chrome — three completely different approaches. Here's a comparison of the current landscape, key differences, and a selection guide.
On 2026/4/22 OpenAI launched Workspace Agents — powered by Codex, capable of long-running cloud execution, and integrating with Slack/Salesforce/Google Drive. They are the enterprise successor to Custom GPTs.
A detailed look at OpenAI's Codex agent loop design: how prompts are constructed, how multi-turn conversations are managed, how prompt caching prevents cost explosions, and how context window auto-compaction works.
OpenAI wrapped the Codex harness as a JSON-RPC over stdio App Server, enabling VS Code, JetBrains, Web, and desktop apps to share a single agent loop. Three core primitives: Item, Turn, and Thread.
An OpenAI internal team spent 5 months with 3 people and 0 lines of hand-written code, delivering a complete product using Codex. This article distills their core lessons on AGENTS.md design, repo-local knowledge bases, architecture enforcement, and entropy management.
Claude Code only reads CLAUDE.md; Codex only reads AGENTS.md. Teams using both end up maintaining two identical files. Fix: make CLAUDE.md a symlink pointing to AGENTS.md — one source of truth.
Comparing six major Agent CLI subscription plans in 2026 (Claude Code, Cursor CLI, Codex, Kiro, Gemini CLI, OpenCode), and exploring multi-model routing patterns — routing simple tasks to cheaper models and complex tasks to flagship models, with real-world savings of 40-85%.
Skill paths are almost always runtime-specific. AGENTS.md is the reliable way to share rules across agents. Put personal reusable capabilities in each agent's supported global directory; put project workflows inside the repo.
Codex CLI is OpenAI's open-source terminal coding agent built in Rust. It supports MCP, subagents, image input, and code review. Paired with the codex-1 (o3-optimized) or GPT-5-Codex model, it can read, write, and execute code directly on your local machine.