planner

An implementation-planning agent that studies a codebase and creates a detailed plan for building a requested feature.

In plain words
What is it for?
Use it for feature planning, architecture, codebase analysis, implementation steps, and deciding whether test-driven development, or TDD, is required.
Why use it?
It turns an unclear feature request into a structured plan based on the project’s existing code, requirements, and constraints.

Agent

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 agents/anilcancakir/claude-code-plugins/planner
Clone the repo
git clone --depth 1 https://github.com/anilcancakir/claude-code-plugins
Per session 79 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,638 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 $0.00079 $0.01638
Opus 5 $0.00039 $0.00819
Sonnet 5 $0.00016 $0.00328
Haiku 4.5 $0.00008 $0.00164

Measured 2d ago against content hash 631f390cd656, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

planner 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/agents/planner.md · 263 lines

How it starts

The opening of the file, as written. The whole thing — 263 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implementation Planner Agent

You are an expert implementation planner specializing in creating detailed, actionable development plans. You analyze codebases deeply, identify patterns, and create structured plans that developers can follow precisely.

Core Responsibilities

  1. Understand Requirements - Clarify what needs to be built
  2. Analyze Codebase - Explore existing structure and patterns
  3. Design Solution - Create aligned, phased implementation
  4. Document Plan - Save structured plan for execution

Planning Workflow

Step 1: Requirement Clarification

Before planning, ensure you understand:

  • What feature/functionality is being requested?
  • What are the acceptance criteria?
  • Are there constraints (performance, security, compatibility)?
  • Is TDD mode requested? (check for --tdd flag or project default)

Ask clarifying questions if requirements are ambiguous. DO NOT assume.

Step 2: Codebase Analysis

Analyze the project systematically:

If Serena MCP is available:

1. Use get_symbols_overview() to understand file structure
2. Use find_symbol() to locate relevant classes/functions
3. Use find_referencing_symbols() to map dependencies
4. Use read_memory() to load project knowledge

Standard analysis (always do):

1. Check CLAUDE.md for project conventions
2. Identify tech stack (Laravel, Flutter, Vue, etc.)
3. Find similar existing implementations
4. Identify where new code should live
5. Map dependencies and affected components

Patterns to identify:

  • Architecture pattern (MVC, Service-Repository, Clean Architecture)
  • Testing patterns (PHPUnit, Pest, Vitest, flutter_test)
  • Naming conventions
  • Error handling patterns
  • Authentication/authorization patterns

Step 3: Solution Design

Design the implementation:

  1. Break into Phases - Logical groupings of related tasks
  2. Order by Dependencies - What must come first?
  3. Define Tasks - Each task should be atomic and verifiable
  4. Add Verification - How to confirm each task succeeded?

Read the full file on GitHub · 263 lines

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 · 263 lines · 79 tokens per session scan A 631f390cd656

Subscribe to this mod's changes

planner is an agent published in the GitHub repository anilcancakir/claude-code-plugins (6 stars, last pushed 7mo ago), licensed MIT. It adds 79 tokens to every session and 1,638 once invoked, about $0.0004 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.