Archon: Command for Claude Code

.claude/commands/plan-feature.md

plan-feature is a command for Claude Code from coleam00/Archon. It costs 10 tokens per session (1,275 once invoked), scanned A, original, MIT.

A command for creating a detailed implementation plan for an Archon feature. Archon is the software project whose packages, interfaces, and workflows the plan examines.

In plain words
What is it for?
Use it before implementation to investigate the codebase, identify files and packages involved, coordinate research, and save a plan for the execute command.
Why use it?
It turns a feature request into defined goals, affected code, boundaries, interfaces, and checks for deciding whether the work is complete.

Command for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: mentions subagents.

This is coleam00/Archon's own configuration. It tells Claude Code how to work on Archon itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything Archon configures →

About the project

Archon is a workflow engine for AI coding agents that turns development processes into YAML-defined sequences with phases, validation gates, and artifacts. Developers use it to run repeatable processes such as planning, implementation, testing, code review, and pull-request creation across projects. The catalogue entries provide commands, agents, skills, hooks, instructions, and settings for working with Archon.

coleam00/Archon · 23,704 stars · on GitHub · archon.diy

Reuse

Borrowing it

Nothing to install: this file belongs to coleam00/Archon. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/coleam00/Archon/dev/.claude/commands/plan-feature.md
Clone the repo
git clone --depth 1 https://github.com/coleam00/Archon

Made for: Claude Code.

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-feature

README.md
[![agentmods](https://agentmods.dev/badge/commands/coleam00/archon/plan-feature/github.svg)](https://agentmods.dev/commands/coleam00/archon/plan-feature)
Your own site
<a href="https://agentmods.dev/commands/coleam00/archon/plan-feature"><img src="https://agentmods.dev/badge/commands/coleam00/archon/plan-feature/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.

agentmods 80×15 button for plan-feature

Your own site · 80×15
<a href="https://agentmods.dev/commands/coleam00/archon/plan-feature"><img src="https://agentmods.dev/badge/commands/coleam00/archon/plan-feature.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,275 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00010 $0.01275
Opus 5.5 $0.00004 $0.00510
Sonnet 5.5 $0.00002 $0.00255
Haiku 4.5 $0.00001 $0.00128

Measured 2d ago against content hash 7ae1a7cd5864, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

plan-feature scanned grade A with 1 finding 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

5. Manual test: {specific curl command or UI steps to verify the feature}
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.claude/commands/plan-feature.md · 169 lines

How it starts

The opening of the file, as written. The whole thing — 169 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plan Feature: Comprehensive Archon Implementation Planning

Objective

Produce a detailed, actionable implementation plan for: $ARGUMENTS

The plan will be saved to .claude/archon/plans/{kebab-case-name}.md and is designed to be consumed by the /execute command.


Phase 1: Feature Understanding

Restate the feature request in your own words. Identify:

  1. Problem being solved — What user pain point or capability gap does this address?
  2. Success criteria — What does "done" look like? How will we verify it works?
  3. Scope boundaries — What is explicitly in scope vs. out of scope?
  4. Package impact — Which workspace packages are affected? Read the root package.json and .archon/architecture.md for the current package map and boundaries.
  5. Interface changes — Does this touch IPlatformAdapter, IAgentProvider, IDatabase, or IWorkflowStore? New interfaces needed?

Phase 2: Codebase Intelligence

Use subagents to perform targeted codebase research in parallel. Spawn separate subagents for:

Subagent A — Affected package deep-dive: Read all relevant source files in the affected packages. Map the current data flow. Identify every file that will need to change.

Subagent B — Interface and type contracts: Read packages/core/src/types/ and relevant index.ts exports. Understand what interfaces exist and how they're consumed across packages.

Subagent C — Test patterns: Find existing test files similar to the area of change:

find packages/ -name "*.test.ts" | head -30

Read 2-3 representative test files to understand mocking patterns, assertion style, and mock.module() isolation requirements per package.

Subagent D — Related prior work:

git log --oneline --all | head -20

Read recent commits touching relevant files to understand change patterns.

Synthesize findings: current state, gaps, constraints.


Phase 3: External Research (if needed)

If the feature involves external APIs, new libraries, or unfamiliar patterns, use web search to research:

Read the full file on GitHub · 169 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 Changed · -1 lines 7ae1a7cd5864
  2. 4d ago Changed · -1 lines 21010c22029c
  3. 1mo ago First seen · 171 lines · 10 tokens per session scan A 2d824ce16c7f

Subscribe to this mod's changes

plan-feature is a command published in the GitHub repository coleam00/Archon (23,704 stars, last pushed today), licensed MIT. It adds 10 tokens to every session and 1,275 once invoked, about $0.0000 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.