fable-opus — Claude Code skill: what it does, how to install
This skill applies fable-mode discipline to Claude Opus when a user asks for thorough, systematic handling of a task.
npx skills add mrtooher/fable-mode --skill fable-opus -a claude-codeWhat fable-opus does
fable-opus turns an explicit request for deep work on Claude Opus into a staged execution flow. The main thread coordinates the work, can start workers through the Agent tool, and waits for every returned result before delivery checks begin.
The skill carries unresolved stages, uncovered scope, and planning ambiguity back to the user. It then runs the double-check skill once on the main thread; high-stakes work can receive an extra verifier when the Agent tool is available. If the task exceeds Opus's capability, the report says so instead of handing it to another tier.
When Opus or the Agent tool is unavailable, stages run inline and sequentially on the current thread. That fallback changes execution, while the delivery gate still applies.
What it helps with
- break a demanding task into checkable stages
- run stage work through Opus and available worker models
- wait for every worker before delivery checks
- surface unverified work and uncovered scope
- run a final double-check on the deliverable
Example prompts for the agent
- Run
fable-opuson this task and handle it as deep work on Opus. - Use
fable on opusfor this request, with a check after each stage. - Apply
stage this on opusand report every part that remains unverified.
How to install fable-opus
1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-opus -a claude-code2Manually: put the files in place
~/.claude/skills/fable-opus/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/fable-opus/
1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-opus -a codex2Manually: put the files in place
.agents/skills/fable-opus/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-opus -a cursor2Manually: put the files in place
.cursor/skills/fable-opus/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install mrtooher/fable-mode fable-opus2Manually: put the files in place
.github/skills/fable-opus/SKILL.md1Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-opus -a gemini-cli2Platform CLI
gemini skills install https://github.com/mrtooher/fable-mode --path fable-opusManually: put the files in place
.devin/skills/fable-opus/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add mrtooher/fable-mode --skill fable-opus -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-opus
How do I install fable-opus in Claude Code?
Run npx skills add mrtooher/fable-mode --skill fable-opus -a claude-code, then check ~/.claude/skills/fable-opus/SKILL.md.
What does fable-opus do?
It applies fable-mode to Claude Opus by coordinating staged work, waiting for agents, returning open issues to the user, and running a final double-check.
What happens when Opus is unavailable?
The skill reports that the Opus pin cannot be used and runs the stages sequentially in the current thread. A task beyond Opus's capability is reported to the user rather than escalated further.
