Harness for Codex

A language-agnostic repository harness for OpenAI Codex, coding agents, Claude Code, and Cursor. It provides durable AGENTS.md instructions, standard automation entrypoints, task templates, verification scripts, and lightweight workflow docs for agent-driven software work.

Use this repository as a Codex harness, AGENTS.md template, or reusable coding-agent project scaffold when you want every future task to start from a predictable baseline:

• one place for agent instructions through AGENTS.md
• one bootstrap command
• one check command
• one test command
• one full evaluation command
• optional hooks and devcontainer metadata
• lightweight documentation for decisions and tasks

Use Cases

• Start a new repository with Codex-ready agent instructions.
• Standardize coding-agent workflows across OpenAI Codex, Claude Code, and Cursor.
• Give automation agents stable commands for setup, checks, tests, and handoff evaluation.
• Keep project decisions and task briefs in predictable locations.
• Add a language stack later without replacing the harness contract.

Quick Start

scripts/bootstrap
scripts/check
scripts/doctor

What This Provides

• AGENTS.md: repository-local operating instructions for Codex and compatible agents.
• CLAUDE.md: Claude Code bridge that imports the shared AGENTS.md guidance.
• scripts/bootstrap: dependency preparation when a known stack is present.
• scripts/check: lint, format, type, and test checks when available.
• scripts/test: focused test-suite entrypoint.
• scripts/eval: complete handoff verification through doctor, bootstrap, and check.
• tasks/TEMPLATE.md: task brief template for work that needs durable context.
• docs/decisions.md: durable decisions future agents should preserve.

Workflow

1. Write the task brief in tasks/ when the work needs context.
2. Implement changes in the relevant project files.
3. Record durable decisions in docs/decisions.md.
4. Run scripts/check before finishing.

Automation Entrypoints

• scripts/bootstrap: install or prepare dependencies when a known stack is present.
• scripts/check: run formatting, linting, type checks, and tests when available.
• scripts/test: run the test suite when available.
• scripts/eval: run doctor, bootstrap, and check as a handoff gate.
• scripts/doctor: print repository and tooling readiness.
• scripts/hooks: install optional local hooks through pre-commit.

If you use just, the same commands are exposed in justfile:

just check
just eval

These scripts are safe defaults for an empty or early-stage repository. Extend them as the project grows.

Compatible Agents

• OpenAI Codex reads AGENTS.md for repository instructions.
• Cursor can use AGENTS.md as shared project guidance.
• Claude Code reads CLAUDE.md, which imports the same shared instructions.

Keep shared rules in AGENTS.md so agent behavior stays consistent across tools. Add tool-specific notes only when a tool requires a different bridge.

Harness Metadata

harness.yml records the canonical command names, expected documentation files, and task-loop stages. Keep it aligned with AGENTS.md and the scripts in this repository.

Optional Environment

The repository includes a minimal dev container that runs scripts/bootstrap after creation. It is optional; local development works without Docker.