Agent skill

Fablize

by fivetaku in fivetaku/fablize

A harness that makes Opus (or any Claude model) behave like Fable — it enforces seeing a task through to the end, with evidence and verification, as procedure.

MITAuto-check passedDevelopment

Install Fablize

skills CLI
$ npx skills add fivetaku/fablize --skill fablize -a claude-code

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

GitHub CLI
$ gh skill install fivetaku/fablize fablize --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/fivetaku/fablize.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/fablize .claude/skills/fablize && 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
fablize
GitHub stars
895
Token cost
~1.6k tokens
SKILL.md length
721 words
Files
1
Skills in repo
1
Repo updated
First seen
Licence
MIT

At a glance

A harness that makes Opus (or any Claude model) behave like Fable — it enforces seeing a task through to the end, with evidence and verification, as procedure.

  • Works in 5 steps: First run — set up automatically (once) → Multi-story loop (2+ sequential stories) → Deep investigation (debugging / unknown… → …
  • Starting a multi-step task (2+ sequential stories)
  • SKILL.md covers 0. First run — set up…, 1. Multi-story loop (2+…, 2. Deep investigation… and 3. Verification grounding…, plus 3 more sections
  • Calls python3 and bash

What it does

Fablize is an agent skill from fivetaku/fablize. A harness that makes Opus (or any Claude model) behave like Fable — it enforces seeing a task through to the end, with evidence and verification, as procedure. Use when starting a multi-step task (2+ sequential stories), long autonomous work, debugging or root-cause investigation, building render/executable artifacts (HTML, SVG, games, charts), or when the user says "fablize", "see it through", "verify as you go", "split into goals".

Its SKILL.md is about 1.6k 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 Development, covering Root cause analysis and Debugging. The repository describes itself as: A Claude Code plugin that makes Opus behave like Fable — completion, evidence, and verification enforced as procedure. Ships only what a Fable-vs-Opus comparison proved… The licence is MIT.

When your agent uses it

  • Starting a multi-step task (2+ sequential stories)
  • Long autonomous work
  • Root-cause investigation
  • Building render/executable artifacts (HTML

Example prompts

  • “fablize”
  • “see it through”
  • “verify as you go”
  • “/fablize”

Requirements

  • Python 3

Workflow steps

5 steps, taken from the step headings in SKILL.md.

  1. First run — set up automatically (once)
  2. Multi-story loop (2+ sequential stories)
  3. Deep investigation (debugging / unknown cause / review)
  4. Verification grounding (render/executable artifacts — always)
  5. At the capability ceiling (escalate)

What it can do on your machine

Read from SKILL.md and the folder at commit e221f32. 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

    Shell commands in SKILL.md call:

    • python3
    • bash

    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

Fablize loads about 1.6k tokens when it runs. Until then it costs about 111 tokens; SKILL.md has 721 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~111
When it runs · the whole SKILL.md, loaded when a task matches
~1.6k

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

The full file from fivetaku/fablize at commit e221f32, republished under its MIT licence (© fivetaku). 721 words, ~1,620 tokens.

Download SKILL.mdSave it as .claude/skills/fablize/SKILL.md (or your agent's skills folder).
name
fablize
description
A harness that makes Opus (or any Claude model) behave like Fable — it enforces seeing a task through to the end, with evidence and verification, as procedure. Use when starting a multi-step task (2+ sequential stories), long autonomous work, debugging or root-cause investigation, building render/executable artifacts (HTML, SVG, games, charts), or when the user says "fablize", "see it through", "verify as you go", "split into goals".

fablize — run Opus like Fable

Principle: a harness cannot raise a model's ceiling. It makes the model go all the way to its own ceiling — by enforcing verification, completion, and investigation as procedure. When the capability ceiling is the blocker (open-ended creative detail, self-driven discovery), escalate (§4).

Apply only what the task signals (smallest matching discipline; overlap only when genuinely multi-category). When installed always-on, this routing is automatic.

0. First run — set up automatically (once)

Before doing the requested task, check whether fablize has been onboarded on this machine:

bash
cat ~/.fablize/progress.json 2>/dev/null
  • If the file exists — skip onboarding, go straight to the task.
  • If it is missing — onboard once with a single AskUserQuestion. Phrase the question and options in the user's current conversation language (detect it from recent messages — Korean, English, Japanese, etc.).
    • Question (meaning, translate to the user's language): "Set up fablize?"
    • Options (meaning, translate): "Local — this project only (recommended)" / "Global — all projects" / "Skip".
    • On Local/Global — run setup (it injects the block and writes progress.json; it never stars anything by itself), then continue with the task:
      bash
      bash ${CLAUDE_PLUGIN_ROOT}/setup/setup.sh <local|global>
      After setup, run bash ${CLAUDE_PLUGIN_ROOT}/setup/setup.sh ask — if it prints STAR_ASK <lang>, ask once via AskUserQuestion (in the user's language) whether they'd like to give the repo an optional GitHub ⭐, then run setup.sh star yes or setup.sh star no accordingly. If it prints nothing, skip silently.
    • On Skip — record it so it won't ask again, then continue:
      bash
      mkdir -p ~/.fablize && printf '{"setup_done":false,"skipped":true}' > ~/.fablize/progress.json

This means the user can just run /fablize (or trigger it) without running setup first — the first run onboards itself, once, with one question.

1. Multi-story loop (2+ sequential stories)

Decompose into sequential stories and complete one at a time, producing evidence as you go. Self-contained — no external goal system required. Run from the repo root; state persists in ./.fablize/ (resume with status even across sessions).

bash
python3 ${CLAUDE_PLUGIN_ROOT}/scripts/goals.py create --brief "<summary>" \
  --goal "title::verifiable objective" --goal "title::..."   # the last goal must be a verification story
python3 ${CLAUDE_PLUGIN_ROOT}/scripts/goals.py next         # activate a story + handoff
# ... work that story only ...
python3 ${CLAUDE_PLUGIN_ROOT}/scripts/goals.py checkpoint --id G001 --status complete --evidence "<concrete evidence>"
# the final story is a verification gate: --verify-cmd "<command>" --verify-evidence "<result>" are required
python3 ${CLAUDE_PLUGIN_ROOT}/scripts/goals.py status       # first command when resuming

Rules: complete requires non-empty evidence; the final goal cannot complete without a verify command and its result (the engine refuses). If blocked, record --status blocked and report. Single-step tasks skip this loop.

2. Deep investigation (debugging / unknown cause / review)

Read and follow ${CLAUDE_PLUGIN_ROOT}/packs/investigation-protocol.txt: reproduce first → form 3+ competing hypotheses → gather evidence per hypothesis → trace the full causal chain (removing the symptom is not removing the defect) → verify before and after → report the hypotheses you rejected. For reviews, report everything including low-confidence findings and filter in a separate step.

3. Verification grounding (render/executable artifacts — always)

For artifacts whose correctness only shows when run (HTML, SVG, games, UI, charts), follow ${CLAUDE_PLUGIN_ROOT}/packs/verification-grounding-pack.txt: run it in the real renderer → observe the actual output → fix what the observation reveals → re-run. A static parse confirms well-formed, not correct.

Show full SKILL.md (282 more words)Show less

3-1. Working style (always)

Lead with the outcome. Stay within the requested scope (no incidental refactors or abstractions). Ground every completion claim in a tool result from this session. Confirm before destructive or hard-to-reverse actions.

4. At the capability ceiling (escalate)

Signals you have hit the model's ceiling: stuck on the same problem 2+ times; open-ended creation where detail itself is the value; deep review that needs out-of-spec discovery. These are capability, not procedure, and a harness cannot fill them. In order: (1) adaptive thinking already scales with difficulty — recommend /effort xhigh to the user to push the current model to its ceiling; (2) reactive effort delegation — if the blocker is a bounded, hard slice (not the whole task), delegate just that slice to a background Workflow with effort:'max' (model inherited): package the evidence (symptoms, attempts, failure point, repro, the specific sub-question) as the agent() prompt, force a structured return via schema, then resume with its result as authoritative. This is the only real per-task effort knob in a normal session — the Agent tool exposes model but no effort; only Workflow/Agent SDK do. Opt-in, and not yet proven on real work (the shadow layer in docs/MEASUREMENT_PROTOCOL.md measures whether it helps): use it for a genuinely stuck slice, not routinely, and never trigger it from risk/deep classification alone — that over-escalates simple high-risk tasks (false-escalate); (3) if still short, hand off to a stronger model in a fresh session with the same evidence package; (4) otherwise report the limit honestly and name where a human must step in.

Install (always-on, optional)

Run once: bash ${CLAUDE_PLUGIN_ROOT}/setup/setup.sh → choose local (recommended) or global. Uninstall: bash ${CLAUDE_PLUGIN_ROOT}/setup/uninstall.sh. The UserPromptSubmit router hook registers automatically when the plugin is installed.

© fivetaku, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/fablize of fivetaku/fablize.

Open the folder on GitHubat commit e221f32

Compare with similar skills

Fablize 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.

Fablize compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Fablize this skillfivetaku/fablize895—~1.6kAutomated safety check: PassMIT
OpenLogi macOS Permissions TriageAprilNEA/OpenLogi23k—~2.5kAutomated safety check: NotesApache-2.0
Bug Finder for daisyUIsaadeghi/daisyui43k—~2.3kAutomated safety check: PassMIT
Root Cause Debugginggarrytan/gstack136k—~1.4kAutomated safety check: PassMIT
Graph-Based Bug Tracingtirth8205/code-review-graph32k1 repos~287Automated safety check: PassMIT
Systematic DebuggingChrisWiles/claude-code-showcase6.1k3 repos~1.2kAutomated safety check: PassNone

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Categories

Questions about Fablize

What does Fablize do?

A harness that makes Opus (or any Claude model) behave like Fable — it enforces seeing a task through to the end, with evidence and verification, as procedure. Fablize is an agent skill from fivetaku/fablize. A harness that makes Opus (or any Claude model) behave like Fable — it enforces seeing a task through to the end, with evidence and verification, as procedure.

When should I use Fablize?

Fablize fits situations like: starting a multi-step task (2+ sequential stories); long autonomous work; root-cause investigation; building render/executable artifacts (HTML.

How do I install Fablize in Claude Code?

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

How do I install Fablize in Codex?

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

Can I use Fablize 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 fivetaku/fablize --skill fablize -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/fablize, .gemini/skills/fablize, .github/skills/fablize and .opencode/skills/fablize in your project.

What does Fablize need to run?

Going by SKILL.md and its folder, Fablize needs the command-line tools its instructions call (python3 and bash). Our summary lists: Python 3.

Does Fablize 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 Fablize 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 Fablize use?

Fablize is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Fablize use?

About 1.6k tokens (SKILL.md is roughly 6.5k 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 Fablize?

Skills that share tags, products or a category with Fablize: OpenLogi macOS Permissions Triage (AprilNEA/OpenLogi, 23k stars), Bug Finder for daisyUI (saadeghi/daisyui, 43k stars), Root Cause Debugging (garrytan/gstack, 136k stars) and Graph-Based Bug Tracing (tirth8205/code-review-graph, 32k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Fablize?

fivetaku (a GitHub user) maintains it in fivetaku/fablize, which has 895 GitHub stars. The repository was last updated on July 6, 2026.

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