New: 98,000+ skills indexed from GitHub repos with 100+ stars · every skill safety-checkedBrowse top skillsTop skills
Esc to closeBrowse all skills
Submit a skillBrowse skills
Submit a skillBrowse skills

Agent skill

Fable Sonnet

by mrtooher in mrtooher/fable-mode

Run fable-mode execution discipline on Claude Sonnet. An agent skill from mrtooher/fable-mode.

No licenceAuto-check passedProductivity & Automation

Install Fable Sonnet

skills CLI
$ npx skills add mrtooher/fable-mode --skill fable-sonnet -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install mrtooher/fable-mode fable-sonnet --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/mrtooher/fable-mode.git skills-src && mkdir -p .claude/skills && cp -r skills-src/fable-sonnet .claude/skills/fable-sonnet && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
fable-sonnet
GitHub stars
870
Token cost
~531 tokens
SKILL.md length
220 words
Files
1
Skills in repo
7
Repo updated
First seen
Licence
None found

At a glance

Run fable-mode execution discipline on Claude Sonnet. An agent skill from mrtooher/fable-mode.

  • Works in 6 steps: Confirm fable-worker-sonnet appears in… → Spawn @fable-worker-sonnet via the Task… → For independent sub-parts, spawn… → …
  • The user explicitly asks for thorough/systematic/deep work handling on Sonnet (fable on sonnet
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
  • Stage this on sonnet

What it does

Fable Sonnet is an agent skill from mrtooher/fable-mode. Run fable-mode execution discipline on Claude Sonnet. Routes the task to the @fable-worker-sonnet agent, whose definition carries the staged loop with step-3 verification enforced hardest (Sonnet's known gap), optionally followed by a cold @fable-verifier pass. Trigger when the user explicitly asks for thorough/systematic/"deep work" handling on Sonnet ("fable on sonnet", "stage this on sonnet", "deep work mode, sonnet"). The balanced default between Haiku (cheap/fast) and Opus/Fable (peak reasoning). Do NOT use…

Its SKILL.md is about 530 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Productivity & Automation, covering Focus and ADHD support. The repository describes itself as: A Claude skill that activates Fable-style agentic behavior: explicit multi-stage planning, sub-agent delegation, and self-verification.

When your agent uses it

  • The user explicitly asks for thorough/systematic/deep work handling on Sonnet (fable on sonnet
  • Stage this on sonnet
  • Ordinary single-pass tasks

Example prompts

  • “deep work”
  • “fable on sonnet”
  • “stage this on sonnet”
  • “/fable-sonnet”

Workflow steps

6 steps, taken from the first numbered list in SKILL.md.

  1. Confirm fable-worker-sonnet appears in the available agent types. If not,
  2. Spawn @fable-worker-sonnet via the Task tool (`subagent_type
  3. For independent sub-parts, spawn multiple workers concurrently and merge.
  4. For high-stakes deliverables, follow with @fable-verifier, briefed with
  5. Relay results and anything marked unverified.
  6. Mandatory delivery gate: before presenting the result to the user, invoke

What it can do on your machine

Read from SKILL.md and the folder at commit a368f94. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Fable Sonnet loads about 531 tokens when it runs. Until then it costs about 141 tokens; SKILL.md has 220 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~141
When it runs · the whole SKILL.md, loaded when a task matches
~531

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

Without a licence we can't republish the file, so here is its outline and opening line. It has 220 words (~531 tokens).

“v3 change: the worker is a real agent definition (agents/fable-worker-sonnet.md) invoked by name, not a prose briefing the model can soft-ignore. Its system prompt carries the loop and the operational rules; this skill only routes.”

— opening of SKILL.md by mrtooher
name
fable-sonnet

Read the full SKILL.md on GitHub

Files

Just SKILL.md in fable-sonnet of mrtooher/fable-mode.

Open the folder on GitHubat commit a368f94

Compare with similar skills

Fable Sonnet next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Fable Sonnet compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Fable Sonnet this skillmrtooher/fable-mode870—~531Automated safety check: PassNone
I Have AdhdTanStack/ai3.2k5 repos~1.8kAutomated safety check: PassMIT
Attention Kindalexgreensh/attention-span1.4k—~2kAutomated safety check: PassAGPL-3.0
Remind Meshaheer-00/claude-adhd104—~1.1kAutomated safety check: PassNone
Daily Focus Boardgithub/awesome-copilot40k—~3kAutomated safety check: PassMIT
Attention Controlaaddrick/attention-control118—~3.6kAutomated safety check: PassMIT

Similar skills

  • I Have Adhd

    TanStack/ai

    A skill your agent uses when the user invokes /i-have-adhd, says they have ADHD, or asks for ADHD-friendly output.

    3.2k GitHub starsUsed in 5 repos~1.8k tokens
    Productivity & AutomationAuto-check passed

  • Attention Kind

    alexgreensh/attention-span

    Answer in the ADHD-friendly Attention-kind style for the rest of this chat.

    1.4k GitHub stars~2k tokensUpdated 1 mo ago
    Productivity & AutomationAuto-check passed

  • Remind Me

    shaheer-00/claude-adhd

    Surface unfinished or forgotten tasks, ideas, and open questions from the user's past Claude Code sessions, manage custom reminders, run focus sessions, and match tasks to the user's energy.

    104 GitHub stars~1.1k tokensUpdated 28 days ago
    Productivity & AutomationAuto-check passed

  • Daily Focus Board

    github/awesome-copilot

    Official

    Builds a warm, browser-based daily focus board the user updates by talking to their agent, with Eisenhower priorities, a brain-dump box and kind not-today carryover.

    40k GitHub stars~3k tokensUpdated yesterday
    Productivity & AutomationAuto-check passed

  • Attention Control

    aaddrick/attention-control

    Shape output for a reader with ADHD, then write each sentence in controlled English: action first, one word one meaning, active voice, simple tenses, state restated every turn.

    118 GitHub stars~3.6k tokensUpdated 2 mo ago
    Productivity & AutomationAuto-check passed

  • Chief Of Staff

    jdpolasky/ai-chief-of-staff

    Personal Chief of Staff system for ADHD-ish operators. An agent skill from jdpolasky/ai-chief-of-staff.

    104 GitHub stars~1.1k tokensUpdated 6 days ago
    Productivity & AutomationAuto-check passed

More from mrtooher/fable-mode

  • Double Check

    mrtooher/fable-mode

    Automatic final verification pass on completed deliverables.

    870 GitHub stars~1.9k tokensUpdated 1 mo ago
    Auto-check passed

  • Execution Guardrails

    mrtooher/fable-mode

    Always-on operational guardrails, model-independent. An agent skill from mrtooher/fable-mode.

    870 GitHub stars~1k tokensUpdated 1 mo ago
    Auto-check passed

  • Fable Fable

    mrtooher/fable-mode

    Run fable-mode execution discipline on Claude Fable 5.1 — the top of the escalation ladder and the strongest staged run available.

    870 GitHub stars~1.1k tokensUpdated 1 mo ago
    Auto-check passed

  • Fable Mode

    mrtooher/fable-mode

    Enforces staged execution discipline on large tasks: a written stage plan, delegation to named fable agents where the runtime supports it, a failable verification check at each stage, and a…

    870 GitHub stars~1k tokensUpdated 1 mo ago
    Auto-check passed

  • Fable Opus

    mrtooher/fable-mode

    Run fable-mode execution discipline on Claude Opus — one rung below Fable 5.1 on the escalation ladder.

    870 GitHub stars~868 tokensUpdated 1 mo ago
    Auto-check passed

  • Fable Haiku

    mrtooher/fable-mode

    Run fable-mode execution discipline on Claude Haiku. An agent skill from mrtooher/fable-mode.

    870 GitHub stars~565 tokensUpdated 1 mo ago
    Auto-check passed

Categories

Questions about Fable Sonnet

What does Fable Sonnet do?

Run fable-mode execution discipline on Claude Sonnet. An agent skill from mrtooher/fable-mode. Fable Sonnet is an agent skill from mrtooher/fable-mode. Run fable-mode execution discipline on Claude Sonnet.

When should I use Fable Sonnet?

Fable Sonnet fits situations like: the user explicitly asks for thorough/systematic/deep work handling on Sonnet (fable on sonnet; stage this on sonnet; ordinary single-pass tasks.

How do I install Fable Sonnet in Claude Code?

Run `npx skills add mrtooher/fable-mode --skill fable-sonnet -a claude-code`. Or copy the skill folder (fable-sonnet in mrtooher/fable-mode) into .claude/skills/fable-sonnet in your project. Claude Code loads it when a task matches its description.

How do I install Fable Sonnet in Codex?

Run `npx skills add mrtooher/fable-mode --skill fable-sonnet -a codex`. Or copy the skill folder (fable-sonnet in mrtooher/fable-mode) into .agents/skills/fable-sonnet in your project. Codex loads it when a task matches its description.

Can I use Fable Sonnet in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mrtooher/fable-mode --skill fable-sonnet -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/fable-sonnet, .gemini/skills/fable-sonnet, .github/skills/fable-sonnet and .opencode/skills/fable-sonnet in your project.

What does Fable Sonnet need to run?

SKILL.md names no scripts, command-line tools or credentials: Fable Sonnet is instructions for the agent only.

Does Fable Sonnet access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Fable Sonnet safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Fable Sonnet use?

No licence was found for Fable Sonnet or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.

How many tokens does Fable Sonnet use?

About 531 tokens (SKILL.md is roughly 2.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Fable Sonnet?

Skills that share tags, products or a category with Fable Sonnet: I Have Adhd (TanStack/ai, 3.2k stars), Attention Kind (alexgreensh/attention-span, 1.4k stars), Remind Me (shaheer-00/claude-adhd, 104 stars) and Daily Focus Board (github/awesome-copilot, 40k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Fable Sonnet?

mrtooher (a GitHub user) maintains it in mrtooher/fable-mode, which has 870 GitHub stars. The repository holds 7 skills in this directory. The repository was last updated on September 2, 2026.

Source: mrtooher/fable-mode on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.