Codex agent

Skill ninjaproger/skills/skills/codex-agent

AI agent skills

Install

npx -y skills add ninjaproger/skills --skill codex-agent

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What its author says it does

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Delegate complex, multi-step coding tasks to the OpenAI Codex CLI agent running in the background. Use when the user wants to offload autonomous coding work to codex — including TCA feature development (new reducer/view/tests in a modular iOS app) and iOS Simulator automation (build, install, navigate, inspect). Codex runs non-interactively via `codex exec`, handles tool calls and file edits autonomously, and returns a final summary. Use for tasks that benefit from background execution: "implement X feature using codex", "have codex add tests for Y", "use codex to navigate the simulator and verify Z", "run codex in the background to build this".

SKILL.md

3.7 KB, 750 tokens by cl100k_base, as published. Nobody here has run it

Codex Agent

Quick Start

# Ensure skills are installed, then run:
codex exec --full-auto --cd [PROJECT_ROOT] \
  "Use the tca-developer skill to implement [FEATURE_NAME]. ..."

Sibling Skill Paths

This skill is part of a plugin. The other skills (tca-developer, tca-architect, ios-simulator) are installed in the same plugin directory as this skill.

Derive their absolute paths by replacing the last path component of this skill's base directory:

This skill's base: .../skills/codex-agent/
tca-developer: .../skills/tca-developer/
ios-simulator: .../skills/ios-simulator/

Use the resolved absolute path wherever <SKILL_PATH> appears below.

Codex registers skills by file path in ~/.codex/config.toml. When the path points to the source skill directory, it always reads the latest SKILL.md from disk — no explicit update step needed.

To check which skills are registered, open an interactive Codex session and run /skills. To install a missing skill, open an interactive Codex session and run $skill-installer install <SKILL_PATH>.

Run

TCA Feature Development

codex exec --full-auto --cd [PROJECT_ROOT] \
  "Use the tca-developer skill to implement [FEATURE_NAME]. \
   Explore Sources/, use [REFERENCE_FEATURE] as style reference. \
   When implementation is done, validate by running: [TEST_COMMAND]. \
   Report test results and a summary of files created."

Where [TEST_COMMAND] is the project's test command, e.g.:

xcodebuild test -project MyApp.xcodeproj -scheme MyAppTests \
  -destination 'platform=iOS Simulator,name=iPhone 17 Pro' -skipMacroValidation

Identify [REFERENCE_FEATURE] by listing Sources/ and picking the nearest existing feature.

iOS Simulator Automation

The ios_sim.py script is at <ios-simulator-skill-path>/scripts/ios_sim.py. Resolve this path from this skill's base directory before running.

codex exec --full-auto \
  "Use the ios-simulator skill to [TASK]. \
   Simulator script: <IOS_SIMULATOR_SKILL_PATH>/scripts/ios_sim.py. Print a summary when done."

TCA Feature Development + Simulator Verification

codex exec --full-auto --cd [PROJECT_ROOT] \
  "Use the tca-developer skill to implement [FEATURE_NAME]. \
   Validate with: [TEST_COMMAND]. \
   Then use the ios-simulator skill to verify the UI. \
   Simulator script: <IOS_SIMULATOR_SKILL_PATH>/scripts/ios_sim.py. Print a summary."

Tips

--full-auto = --sandbox workspace-write --ask-for-approval never — Codex edits files and runs shell commands without pausing
Use --output-last-message /tmp/result.md for long runs, then read the file to review the summary
For simulator tasks, provide the UDID or tell Codex to run ios_sim.py list first
codex exec resume --last continues the previous session

References

references/codex-cli.md — Full flag reference for codex exec. Read when you need non-default flags (output format, sandbox mode, session resume).

What ships with it: 1 file

2.9 KB alongside SKILL.md

references/

codex-cli.md2.9 KB