Samaschke Codex Implementation Skills

Codex-compatible port of the implementation-skills workflow plugin. The plugin provides skills for shaping work, planning implementation slices, implementing tracker items, committing, opening PRs, reviewing, merging, delegating to local PI/Codex/Claude lanes, and applying long-horizon Codex work discipline.

Skill Families

• Workflow pipeline: prepare-work, plan-slices, implement-issues, requirements-checker, commit-and-push, pr-and-merge.
• Delegation lanes: dispatcher, codex-worker, use-pi, pi-delegate, use-claude.
• Codex discipline: codex-mindset, codex-long-horizon, codex-coding, codex-debugging, codex-research, codex-orchestration.
• Environment setup: configure-codex-roles installs and updates the workload-specific native Codex subagent roles in the user's Codex home.

OpenAI Model Routing

The delegation skills route only to models the selected engine actually offers. Current defaults follow the GPT-5.6 family:

Model	Use it for	Typical effort
GPT-5.6 Luna	Bounded, cost-sensitive, high-volume work, focused audits, and localized one-component implementation	low/medium
GPT-5.6 Terra	Routine or multi-component implementation, repo analysis, contained debugging, and ordinary review	medium/high
GPT-5.6 Sol	Complex coding, architecture, adversarial review, ambiguity, security/concurrency/data work, and broad changes	high/xhigh
GPT-5.6 Sol at max	The hardest quality-first work or repeated failed attempts	max

gpt-5.5 remains a compatibility fallback when the appropriate GPT-5.6 tier is not offered. The skills re-dispatch and report the fallback instead of silently changing model or provider.

GPT-5.6 in Codex requires Codex CLI 0.144.0 or newer and account/workspace access. PI routes GPT models only through its openai-codex provider; check the exact local offer with pi --list-models.

Install

Install directly from the Git repository:

codex plugin marketplace add https://git.samaschke.de/ksamaschke/implementation-skills-codex.git --ref main
codex plugin add implementation-skills@samaschke-codex-skills

From an existing local checkout, add the checkout root as a marketplace instead:

codex plugin marketplace add .
codex plugin add implementation-skills@samaschke-codex-skills

Configure Native Codex Roles

The plugin includes an optional configure-codex-roles skill. Ask Codex to "configure the recommended Codex subagent roles" after installation, or invoke the skill again after an update to reconcile the latest assignments. It manages only the six implementation-skills role names and their files under $CODEX_HOME/agents/ (~/.codex/agents/ by default), preserving unrelated Codex configuration.

The bundled script also supports deterministic provisioning:

python3 <skill-directory>/scripts/configure_roles.py apply \
  --codex-home "${CODEX_HOME:-$HOME/.codex}"

Use status instead of apply for a read-only drift check, or remove to remove the managed role definitions. Start a new Codex session after applying or removing roles.

After Updating

Codex loads skills when a session or process starts. Existing chat sessions, codex exec resume, T3 dedicated harnesses, and long-lived worker pools can keep using an older cached skill after codex plugin add. After updating this plugin, start a fresh Codex session/process or restart the harness pool before expecting changed skill behavior such as implement-issues parallel N.

Quick probe:

codex exec --ephemeral -C . 'Do not edit files or run commands. Report the path for implementation-skills:implement-issues and whether it mentions parallel N.'

Validation

This repo does not vendor Codex's plugin and skill validator helpers. They are provided by the local Codex system skills under $CODEX_HOME/skills/.system (~/.codex/skills/.system by default). Use the repo wrapper so release checks do not depend on remembering those absolute paths:

scripts/validate-plugin.sh

Optional Session Backends

The skills work without extra terminal tooling, but long-running subagent workers are easier to supervise with a session backend.

• Recommended: herdr for API/CLI-driven agent sessions, panes, waits, reads, sends, and worktree-aware workflows.
• Unix fallback: tmux on macOS/Linux when Herdr is unavailable.
• Portable fallback: raw background process supervision with .out/.exit sentinel files.

On macOS or Linux with Homebrew:

brew install herdr
brew install tmux

The plugin does not install system packages during plugin installation. On the first relevant skill use, an agent should run the session backend doctor and ask before installing Herdr or tmux. Noninteractive runs fall back to raw sentinel supervision unless the project config requires a specific backend.

Configuration

Codex skills read these files first:

• .codex/implementation-skills.md
• .codex/git-ops.md

The same configuration settings can also live in these shared paths for repos that are used by both Codex and Claude workflows:

• .claude/implement-issues.md
• .claude/git-ops.md

When both exist, .codex/* wins. Newly learned Codex settings are written to .codex/*.

Project rules may live in AGENTS.md, CODEX.md, CLAUDE.md, or CONTRIBUTING.md.