fable-mode — Claude Code skill: what it does, how to install
Enforces execution structure for deep tasks with mapped stages, subagent delegation, failable checks, and disciplined self-review.
npx skills add mrtooher/fable-mode --skill fable-mode -a claude-codeWhat fable-mode does
The skill structures how an agent executes multi-file work. It requires a numbered stage plan with explicit deliverables before any edits start. Churn is capped: no more than two structural replans are allowed per task. If a third reorganization is needed, the model must halt and prompt for user guidance.
When the host environment has agent tools and the user explicitly calls the skill, independent stages run concurrently via delegated workers. Indirect triggers keep execution in a single thread. Every stage must produce an artifact validated by a test that can actually fail, blocking lazy sign-offs.
The workflow tunes its overhead to the model tier. Stronger frontier models skip narrating the loop to focus on external checks, while lighter models face strict verification fences. Hitting a session budget limit of 75% or weekly 50% forces a pause to confirm next steps with the user.
What it helps with
- structure sprawling changes into sequential stages with clear outputs
- delegate disjoint implementation tasks to parallel subagents
- prevent fake completions through tests designed to expose flaws
- stop endless replanning loops on ambiguous requirements
Example prompts for the agent
- Run fable-mode to migrate the database schema and adapt all queries.
- Refactor the payment gateway using fable mode with strict verification.
- Apply fable-mode to split this monolithic service into modular handlers.
How to install fable-mode
1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-mode -a claude-code2Manually: put the files in place
~/.claude/skills/fable-mode/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/fable-mode/
1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-mode -a codex2Manually: put the files in place
.agents/skills/fable-mode/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-mode -a cursor2Manually: put the files in place
.cursor/skills/fable-mode/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install mrtooher/fable-mode fable-mode2Manually: put the files in place
.github/skills/fable-mode/SKILL.md1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-mode -a gemini-cli2Platform CLI
gemini skills install https://github.com/mrtooher/fable-modeManually: put the files in place
.devin/skills/fable-mode/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-mode -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: How to install skills in Claude Code: five ways
Questions about fable-mode
How to install fable-mode in Claude Code?
Run npx skills add mrtooher/fable-mode --skill fable-mode -a claude-code or save the definition directly to ~/.claude/skills/fable-mode/SKILL.md.
What does fable-mode do?
It provides an execution framework for complex development tasks. The skill enforces upfront stage mapping, parallel subagent spawns where supported, and failable verification gates.
When are subagents allowed to spawn?
Spawning requires an explicit invocation by name or slash command. Autonomous activations or generic prompts like "be thorough" restrict the entire process to run inline.
