plan

plan is a skill for Claude Code, Codex from melodic-software/claude-code-plugins. It costs 100 tokens per session (9,091 once invoked), scanned A, original, MIT.

A structured implementation-plan writer for software changes.

In plain words
What is it for?
It produces a plan document, assesses parallel work and blast radius, and pauses for user approval before implementation.
Why use it?
It makes the goal, approach, testing, risks, and affected areas explicit before code is written.

Skill for Claude CodeCodex

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the planning plugin — 10 skills shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/melodic-software/claude-code-plugins/plan
Any agent
npx skills add melodic-software/claude-code-plugins --skill plan
Clone the repo
git clone --depth 1 https://github.com/melodic-software/claude-code-plugins

Made for: Claude Code, Codex.

Or install planning, the plugin that ships this one along with the rest of its 10 skills.

Wrote 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.

agentmods badge for plan

README.md
[![agentmods](https://agentmods.dev/badge/skills/melodic-software/claude-code-plugins/plan.svg)](https://agentmods.dev/skills/melodic-software/claude-code-plugins/plan)
Your own site
<a href="https://agentmods.dev/skills/melodic-software/claude-code-plugins/plan"><img src="https://agentmods.dev/badge/skills/melodic-software/claude-code-plugins/plan.svg" alt="Measured on agentmods" height="20"></a>
Per session 100 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 9,091 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00100 $0.09091
Opus 5 $0.00050 $0.04546
Sonnet 5 $0.00020 $0.01818
Haiku 4.5 $0.00010 $0.00909

Measured yesterday against content hash f77c4e8b5d04, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plan 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 yesterday.

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.

plugins/planning/skills/plan/SKILL.md · 303 lines

How it starts

The opening of the file, as written. The whole thing — 303 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Pre-computed context

Current branch: !git branch --show-current 2>/dev/null || echo "unknown" Recent commits: !git log --oneline -5 2>/dev/null || echo "no commits" Working tree status (empty = clean): !{ git status --porcelain 2>/dev/null || echo "(git status unavailable)"; } | head -10

Variables

Arguments: $ARGUMENTS

Purpose

Plans fail when they skip rationale, ignore blast radius, or rush past approval gates. This skill structures the planning step so that every implementation starts with a clear design, with evidence, test strategy, and user sign-off, before a single line of code is written.

This is not Claude Code's built-in plan mode (shift+tab). That is a permission mode: read-only exploration. This skill is a planning discipline: the intellectual work of designing an approach, assessing risks, and getting approval. The two complement each other: use plan mode for safe exploration during planning, and this skill for the structured process around it.

This skill takes the outputs of the earlier stages, exploration (local understanding), research (external evidence), and /planning:design (types, contracts, module boundaries, package topology), and produces a plan the user approves before execution begins.

Philosophy: a 2-minute plan prevents a 20-minute rework cycle. The depth of planning should match the blast radius. A one-file fix gets a brief plan; a cross-cutting architecture change gets a full plan with stress-testing and research-iterate loops.

Emit checklist

For multi-step planning sessions (almost always: steps 1-5 of this skill), copy templates/checklist.md into the topic's memory slice as <memory_dir>/<topic-slug>/plan-checklist.md (default .work/). Tick each - [ ] as the corresponding step completes. Step 3 (Plan stress-test via fresh-context sub-agent) and Step 5 (Present for approval) are non-negotiable ticks. Stress-test before presenting, always.

Skip when: mid-flight review replan only. Append a dated scope-change note and revise the PLAN phases instead; do not spawn a second checklist file.

Read the full file on GitHub · 303 lines

Files

What ships with it

10 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.

Changes

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.

  1. yesterday First seen · 303 lines · 100 tokens per session scan A f77c4e8b5d04

Subscribe to this mod's changes

plan is a skill published in the GitHub repository melodic-software/claude-code-plugins (15 stars, last pushed today), licensed MIT. It adds 100 tokens to every session and 9,091 once invoked, about $0.0005 per session on Opus 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 2026-09-03.

Related

Other skills, from other repositories

parallel-orchestrator

Manage parallel Claude Code workstreams using git worktrees. Use when: splitting large tasks across multiple workers, coordinating parallel development, monitoring worker progress, integrating completed work, analyzing work item documents (code reviews, issue lists). Triggers: parallel, orchestrator, worktrees…

jimmc414/claude-code-plugin-marketplace · 78 tokens

parallel-worker

Execute focused implementation tasks in a parallel workflow. Use when: working on assigned files in a worktree, making checkpoint commits, signaling dependencies or blockers, completing orchestrator-assigned tasks. Triggers: worker, checkpoint, worktree, assigned scope, commit prefix, parallel task.

jimmc414/claude-code-plugin-marketplace · 59 tokens

generate-tree-structure

For tree/maze generation: spanning trees, random mazes, graph coverage. Uses frontier-based exploration with configurable traversal order.

jimmc414/claude-code-plugin-marketplace · 30 tokens

optimize-local-search

For NP-hard optimization: TSP, scheduling, assignment problems. Uses greedy construction + local improvement (2-opt, hill climbing).

jimmc414/claude-code-plugin-marketplace · 31 tokens

pass-function-as-arg

For generic algorithms: strategy pattern, callbacks, configurable behavior. Pass functions as parameters to customize algorithm behavior.

jimmc414/claude-code-plugin-marketplace · 27 tokens

solve-constraint-puzzle

For constraint satisfaction: Sudoku, scheduling, N-queens, logic puzzles, SAT-like problems, assignment problems. Uses propagate-then-search pattern.

jimmc414/claude-code-plugin-marketplace · 36 tokens