Borrowing it
Nothing to install: this file belongs to Chachamaru127/codex-harness. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Chachamaru127/codex-harness/main/.codex/skills/planning/SKILL.mdgit clone --depth 1 https://github.com/Chachamaru127/codex-harnessWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/chachamaru127/codex-harness/planning)<a href="https://agentmods.dev/skills/chachamaru127/codex-harness/planning"><img src="https://agentmods.dev/badge/skills/chachamaru127/codex-harness/planning/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/chachamaru127/codex-harness/planning"><img src="https://agentmods.dev/badge/skills/chachamaru127/codex-harness/planning.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00065 | $0.00888 |
| Opus 5.5 | $0.00026 | $0.00355 |
| Sonnet 5.5 | $0.00013 | $0.00178 |
| Haiku 4.5 | $0.00006 | $0.00089 |
Grade A, and why
plan-with-agent scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Planning Skill
Organizes ideas and requirements, converting them into executable tasks in Plans.md.
Quick Reference
- "Create a plan" → this skill
- "Turn what we talked about into a plan" → extract from conversation
- "Want to organize what to build" → start with hearing
- "Plan with TDD" → force TDD adoption
- "CI/benchmark" →
--cimode
Deliverables
- Plans.md - Task list executable with
/work(required) - Feature priority matrix - Required/Recommended/Optional classification
Usage
/plan-with-agent # Interactive planning
/plan-with-agent --ci # CI mode (non-interactive)
Mode-specific Usage
| Mode | Command | Description |
|---|---|---|
| Solo mode | /plan-with-agent |
Claude Code alone: plan → execute → review |
| 2-agent mode | /plan-with-cc (Cursor) |
Plan with Cursor → Execute with Claude Code |
Feature Details
| Feature | Reference |
|---|---|
| Execution Flow | See references/execution-flow.md |
| TDD Adoption | See references/tdd-adoption.md |
| Priority Matrix | See references/priority-matrix.md |
Execution Flow Overview
- Step 0: Check conversation context (extract from previous conversation or start fresh)
- Step 1: Hearing what to build
- Step 2: Increase resolution (max 3 questions)
- Step 3: Technical research (WebSearch)
- Step 4: Extract feature list
- Step 5: Create priority matrix (Required/Recommended/Optional)
- Step 5.5: TDD adoption judgment and test design
- Step 6: Effort estimation (reference)
- Step 7: Generate Plans.md with quality markers
- Step 8: Guide next actions
Auto-invoke Skills
| Skill | When to Call |
|---|---|
setup |
Call first (executes adaptive setup) |
vibecoder-guide |
When user is non-technical |
Quality Markers (Auto-assigned)
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 85 lines · 65 tokens per session scan A 9689eb71e55b
plan-with-agent is a skill published in the GitHub repository Chachamaru127/codex-harness (2 stars, last pushed 8mo ago), licensed MIT. It adds 65 tokens to every session and 888 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
local-ai-agents
Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
next-cache-components-adoption
Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…
chat-pet-sprite-creation
Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.
cpu-profile-analysis
Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…
insight-error-page
Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…