# Codex Features and Practical Usage 🧩 Tired of re-explaining the same workflow to Codex every time? Agent Skills let you package a reusable playbook once, and Codex loads it only when it is actually needed. 🏷️ Title: Agent Skills (SKILL.md) 🔗 URL: 📘 Overview Agent Skills package routine workflows into a single `SKILL.md` file you can reuse. Only a skill's name and description sit in Codex's context at all times; the full body loads when Codex decides to invoke it. You scope skills by where you place them: repository-wide, personal, or machine-level. ⚙️ How It Works ・A skill is a folder with `SKILL.md` (required) plus optional `scripts/` (executable code), `references/` (docs), `assets/` (templates), and `agents/openai.yaml` (UI config). ・`SKILL.md` opens with frontmatter containing `name` and `description`. A good description states clearly when the skill triggers and what its boundaries are. ・Codex scans several locations in priority order: the repo's `.agents/skills`, `$REPO_ROOT/.agents/skills`, your personal `$HOME/.agents/skills`, the admin path `/etc/codex/skills`, and OpenAI's bundled built-in skills. ・Progressive disclosure keeps only names, descriptions, and paths in the initial context (capped around 8,000 characters). The full body loads on invocation, so many installed skills won't bloat the prompt. 🛠️ Practical Usage ・The easiest way to author one is the built-in `$skill-creator`. It walks you through what the skill does, when it triggers, and whether to bundle scripts (instruction-only is the default). ・Invoke explicitly with `/skills` in the CLI/IDE, or mention a skill by name like `$skill-name`. Codex also selects skills implicitly when your task matches the description. ・To forbid implicit selection for a skill, set `policy.allow_implicit_invocation` to `false` in `agents/openai.yaml`. ・To disable a skill without deleting it, add a `[[skills.config]]` entry with its `path` and `enabled = false` in `~/.codex/config.toml`. 💡 Use Cases Encode error-prone, brittle routines such as release procedures, how to run the E2E suite, or the correct way to use an internal library. Anyone on the team then gets consistent results from Codex. Put shared workflows under the repo and personal habits under `$HOME/.agents/skills` for a clean split. ⚠️ Caveats ・Duplicate skill names across locations are not merged; both appear in the selector, so keep names unique. ・A vague description breaks implicit matching. Front-load key use cases and be concrete. ・With many skills installed, descriptions may be shortened to save context. If changes don't show up, restart Codex. #OpenAICodex# #AgentSkills#

# Codex Features and Practical Usage 📝 Stop repeating the same context in every prompt. AGENTS.md is a layered instruction file that teaches Codex your build steps and code conventions for good. 🏷️ Title: Hierarchical Project Instructions (AGENTS.md) 🔗 URL: 📘 Overview AGENTS.md files are persistent instructions Codex reads before starting work. Encode your project norms, build commands, and code standards in Markdown, and Codex automatically discovers and applies them. The defining trait is a layered model where files closer to your current directory take precedence. ⚙️ How It Works Codex builds an instruction chain with strict precedence. ・Global (`~/.codex/`): checks `AGENTS.override.md` first, then `AGENTS.md` ・Project (Git root down to cwd): at each level checks `AGENTS.override.md`, then `AGENTS.md`, then custom fallback names ・Merge: files concatenate from the root downward with blank lines; later files (closer to cwd) override earlier ones It stops adding files once the combined size hits `project_doc_max_bytes` (32 KiB default). Naming conventions: ・`AGENTS.md`: the standard instruction file ・`AGENTS.override.md`: a temporary replacement that takes precedence at its level ・fallback names: configurable via `project_doc_fallback_filenames` (e.g. `TEAM_GUIDE.md`) 🛠️ Practical Usage Split by role for best effect. ・`~/.codex/AGENTS.md` (global): universal personal preferences, e.g. "Always run `npm test` after editing JS," "Prefer `pnpm`" ・repo-root `AGENTS.md`: team norms like linting standards, documentation expectations, and review criteria ・subdirectory `AGENTS.override.md` (e.g. `services/payments/`): override broader rules for a specific domain without deleting parent guidance Verify what loaded by asking Codex to summarize the current instructions, e.g. `codex --ask-for-approval never "Summarize the current instructions."` 💡 Use Cases In a monorepo where only the payments service needs a different test command or review bar, dropping a `services/payments/AGENTS.override.md` switches the rules on only when Codex works under that path. The "Review guidelines" you write here also apply to GitHub's `@/codex review`. ⚠️ Caveats Codex rebuilds the instruction chain on every run, so there is no cache to clear — if guidance looks stale, restart in the target directory. Empty files are skipped and non-existent fallback names are ignored. The `CODEX_HOME` environment variable overrides the default profile location. #OpenAICodex# #AGENTSmd#

# Codex Features and Practical Usage 🚀 "One agent for everywhere you code." OpenAI Codex is an AI coding agent you can hand entire tasks to — from generation to understanding, review, and debugging. 🏷️ Title: Codex Fundamentals 🔗 URL: 📘 Overview Codex is OpenAI's AI coding agent for software development. Rather than just autocompleting code, it reads your existing project structure and conventions and carries out tasks autonomously. It is built into the ChatGPT Plus, Pro, Business, Edu, and Enterprise plans. ⚙️ How It Works Codex centers on five core capabilities. ・Code generation: describe what you want, and it writes code that fits your existing structure and naming conventions. ・Codebase understanding: it reads complex or legacy code and explains how the system is organized. ・Code review: it surfaces bugs, logic errors, and unhandled edge cases. ・Debugging: it traces failures, diagnoses root causes, and proposes targeted fixes. ・Task automation: it handles refactors, tests, migrations, and setup workflows. Underpinning all of this are two foundations that keep it safe: a sandbox that defines execution boundaries, and an approval policy that decides when to stop and ask. 🛠️ Practical Usage Codex's hallmark is that it runs "everywhere you code," through several entry points. ・CLI: launch `codex` in your terminal and work interactively ・IDE extension: delegate right from your editor ・Web / cloud: run tasks on repos you do not have locally, in parallel ・GitHub integration: ask for a review with `@/codex review` on a PR ・Slack integration: mention `@/codex` in a thread to kick off a task A good path is to start with the CLI via `npm i -g @/openai/codex`, then expand into GitHub and Slack as you get comfortable. 💡 Use Cases Practical patterns include: on day one in an unfamiliar repo, asking "Tell me about this project" to grasp the big picture; having bugs cleaned up before review; or delegating a tedious bulk refactor wholesale. Humans stay focused on direction and review. ⚠️ Caveats Codex is an autonomous agent that reads/writes files and runs commands. Create Git checkpoints (commits) before and after tasks so you can always roll back safely. Authenticating with a ChatGPT account is recommended; some functionality may be limited with API-key auth. #OpenAICodex# #AICoding#

I wish @OpenAI Codex / Desktop ChatGPT could have folders for projects so that I could categorize things a bit more, its getting a bit messy on the side there and I dont want to remove projects that are cold as I will come back to them

One thing in @OpenAI Codex keeps confusing me: If you click "New Chat", it always creates a new "chat" in the current project. So basically a new thread. But I would expect it to create a new chat without any project! There used to be setting for this, but now it's gone. 🤷‍♂️