fableplan

A Claude Code skill that delegates implementation planning to a Fable 5 planning subagent, then builds from that plan in your main session — and, when a GitHub issue is referenced, posts the vetted plan to the issue as a comment.

The idea: let a dedicated planning model (Fable 5) produce a concrete, ordered implementation plan before any code is written, review it against the real codebase, preserve it on the tracker, and only then build — in an isolated git worktree so your working tree is never touched.

What it does

Trigger it with /fableplan, "fableplan this", or "plan this with fable", plus a task description and optionally a GitHub issue (#N, a full URL, or owner/repo#N).

The skill then runs a 7-step flow:

1. Resolve the GitHub issue (only if one is referenced) so the planner works from the real requirements, not a paraphrase.
2. Dispatch the Fable 5 Plan subagent, confirm it made no edits, and save the plan verbatim to a scratch file.
3. Sanity-check the plan against the actual codebase (files, symbols, conventions). It stops and asks you if the plan is structurally wrong rather than silently re-planning.
4. Post the vetted plan to the GitHub issue as a comment (only if one was referenced).
5. Present the plan to you.
6. Set up an isolated git worktree so the build never touches your current workspace.
7. Build the task from the plan, inside that worktree.

Install

As a plugin (recommended)

This repo is a Claude Code plugin marketplace. Inside any Claude Code session:

/plugin marketplace add richkuo/fableplan
/plugin install fableplan@fableplan

The skill is picked up automatically from the plugin's skills/ directory, and updates flow through the plugin system.

With npx (npm)

Published to npm as @fableplan/fableplan. One command copies the skill into ~/.claude/skills/:

npx @fableplan/fableplan

Add --project to install into the current repo's .claude/skills/ instead of your personal directory.

Ask Claude Code to install it

Paste this straight into a Claude Code prompt:

Install the fableplan skill from https://github.com/richkuo/fableplan into ~/.claude/skills — fetch skills/fableplan/SKILL.md and place it at ~/.claude/skills/fableplan/SKILL.md

With npx skills

If you use Vercel Labs' skills CLI, it discovers the skills/fableplan/SKILL.md layout automatically:

npx skills add richkuo/fableplan

This installs into .claude/skills/ (and any other agents it detects). It's a third-party tool, separate from the official plugin marketplace above.

Manual (single file)

A Claude Code skill is just a directory containing a SKILL.md, so you can also install it with one command — no clone needed:

mkdir -p ~/.claude/skills/fableplan && curl -fsSL https://raw.githubusercontent.com/richkuo/fableplan/master/skills/fableplan/SKILL.md -o ~/.claude/skills/fableplan/SKILL.md

This puts it in your personal skills directory (~/.claude/skills/), available in every project. To scope it to a single project instead, put the file at <repo>/.claude/skills/fableplan/SKILL.md.

Verify

Start a new Claude Code session (or restart the current one), then run:

/fableplan <task to plan>

Requirements

• Claude Code with access to the fable model for the planning subagent.
• gh (GitHub CLI), authenticated, if you want the issue-comment step.
• A git repository for the build step (the skill stops and asks if the working directory isn't one).

Notes

• The planning subagent always runs on Fable 5 regardless of your main session's model.
• The skill adapts to the target repo's conventions (e.g. its CLAUDE.md); behavior isn't hardcoded to any one project.

License

MIT — see LICENSE.