plan

A planning guide for breaking software work into clear phases, tasks, dependencies, and verification steps before coding.

In plain words
What is it for?
Use it for feature design, architecture decisions, multi-file changes, and work where several implementation approaches are possible.
Why use it?
It helps decide when planning is worthwhile and provides a repeatable way to understand an existing codebase before changing it.

Skill for Claude CodeCodex

Part of the implementation-planner plugin — 3 skills, 3 commands, 3 agents, 1 hook 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/anilcancakir/claude-code-plugins/plan
Any agent
npx skills add anilcancakir/claude-code-plugins --skill plan
Clone the repo
git clone --depth 1 https://github.com/anilcancakir/claude-code-plugins

Made for: Claude Code, Codex.

Or install implementation-planner, the plugin that ships this one along with the rest of its 3 skills, 3 commands, 3 agents, 1 hook.

Per session 60 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 569 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 $0.00060 $0.00569
Opus 5 $0.00030 $0.00284
Sonnet 5 $0.00012 $0.00114
Haiku 4.5 $0.00006 $0.00057

Measured 2d ago against content hash 7dae1e395164, 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 2d 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.

implementation-planner/skills/plan/SKILL.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implementation Planning Skill

Guidelines for creating effective implementation plans.

When to Use Planning

Plan When

  • Feature spans multiple files/components
  • Architecture decisions needed
  • Multiple valid approaches exist
  • Dependencies need coordination
  • Risk of rework is high

Skip Planning When

  • Single file change
  • Bug fix with clear solution
  • Following existing pattern exactly
  • Simple CRUD operation

Planning Phases

1. Requirements Clarification

  • What exactly needs to be built?
  • What are the acceptance criteria?
  • What constraints exist? (performance, security, compatibility)
  • Is TDD expected?

2. Codebase Analysis

  • Explore existing structure
  • Find similar implementations
  • Identify patterns and conventions
  • Map dependencies

3. Solution Design

  • Break into logical phases
  • Order by dependencies
  • Define atomic tasks
  • Add verification steps

4. Documentation

  • Save structured plan
  • Include specific file paths
  • Add verification commands

Plan File Location

.claude/plans/{YYYYMMDD}-{HHMMSS}-{slug}.md

Analysis Strategies

Standard Analysis

  1. Read CLAUDE.md for conventions
  2. Use Grep/Glob to find similar code
  3. Read key files to understand patterns
  4. Map where new code should live

Serena-Enhanced Analysis

  1. get_symbols_overview() - file structure
  2. find_symbol() - locate classes/functions
  3. find_referencing_symbols() - dependency mapping
  4. read_memory() - project knowledge

Task Granularity

Good task:

### Task 1.1: Create User Model
- **File**: app/Models/User.php
- **Action**: Create
- **Verification**: `php artisan tinker` → `new User()` works

Too vague:

### Task 1.1: Set up user system
- **Action**: Create everything for users

Verification Types

Type Example
Command php artisan test --filter=UserTest
File Check File exists at expected path
Syntax No errors when loading file
Manual User confirms behavior

Read the full file on GitHub · 103 lines

Files

What ships with it

1 file 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. 2d ago First seen · 103 lines · 60 tokens per session scan A 7dae1e395164

Subscribe to this mod's changes

plan is a skill published in the GitHub repository anilcancakir/claude-code-plugins (6 stars, last pushed 7mo ago), licensed MIT. It adds 60 tokens to every session and 569 once invoked, about $0.0003 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 2026-08-31.

Related

Other skills, from other repositories