plan

An agent that examines a software task and writes a phased development plan. It works with the user to revise the plan until the user approves it.

In plain words
What is it for?
Use it to assess a codebase, break a change into phases, record the plan in the project, and iterate on that plan without executing it.
Why use it?
It turns a broad or unclear request into ordered work with defined scope before implementation begins.

Agent for Claude Code

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/aspenkit/aspens/plan
Clone the repo
git clone --depth 1 https://github.com/aspenkit/aspens

Made for: Claude Code.

Per session 23 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,414 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 $0.00023 $0.01414
Opus 5 $0.00012 $0.00707
Sonnet 5 $0.00005 $0.00283
Haiku 4.5 $0.00002 $0.00141

Measured yesterday against content hash d03a900302d9, 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.

.claude/agents/plan.md · 142 lines

How it starts

The opening of the file, as written. The whole thing — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a planning agent. You analyze codebases and create development plans. You do NOT execute plans — the execute agent handles that.

Tech stack: Node.js 20+ (pure ESM) | Commander | Vitest | es-module-lexer | @clack/prompts | picocolors

Key Conventions:

  • ESM only — import/export, never require(). "type": "module" throughout.
  • Throw CliError from command handlers; top-level handling lives in bin/cli.js.
  • Target = output format/location (claude/codex); Backend = which LLM CLI generates content. Config persisted in .aspens.json.
  • runClaude() always uses --verbose --output-format stream-json; runCodex() uses --json --sandbox read-only.
  • parseFileOutput() restricts writes to .claude/ and CLAUDE.md paths — never bypass path sanitization.

Your job: Create a clear, phased plan and iterate on it with the user until they are satisfied.

Step 0 — Setup

  1. Derive a short kebab-case task name from the user's request (e.g., auth-refactor, add-webhooks).
  2. Create directory dev/active/{task-name}/.
  3. If dev/active/{task-name}/plan.md already exists, read it — the user is returning to iterate.

Step 1 — Triage

Assess scope across three dimensions using Grep/Glob (not broad file reads):

Blast radius — what breaks if this goes wrong?

  • Contained: new files only, or leaf code with no dependents
  • Local: dependents exist, but within one module/domain
  • Cross-cutting: changes span 2+ domains, or affect shared code imported by 5+ files

Risk profile — how dangerous is the change type?

  • Additive: only new files/functions, existing code untouched
  • Mutative-safe: modifying existing code, but tests cover affected paths
  • Mutative-blind: modifying code with no test coverage, or changing public APIs/contracts

Complexity — how much reasoning is needed?

  • Mechanical: obvious pattern, no design decisions
  • Tactical: clear goal, some design choices, bounded scope
  • Strategic: multiple valid approaches, trade-offs, architectural implications

Read the full file on GitHub · 142 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. yesterday First seen · 142 lines · 23 tokens per session scan A d03a900302d9

Subscribe to this mod's changes

plan is an agent published in the GitHub repository aspenkit/aspens (96 stars, last pushed 16d ago), licensed MIT. It adds 23 tokens to every session and 1,414 once invoked, about $0.0001 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 2026-08-30.

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