The Fable Method is a set of agent workflows that organize tasks into deciding what is needed, taking the smallest appropriate action, and proving the result with verification. It is intended for AI agents that need repeatable behavior grounded in evidence and explicit completion checks. The catalogue entries are the project's skills, instruction, and plugin implementing those workflows.
Borrowing it
Nothing to install: this file belongs to Sahir619/fable-method. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Sahir619/fable-method/main/AGENTS.mdgit clone --depth 1 https://github.com/Sahir619/fable-methodWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/sahir619/fable-method/agents-md)<a href="https://agentmods.dev/instructions/sahir619/fable-method/agents-md"><img src="https://agentmods.dev/badge/instructions/sahir619/fable-method/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/sahir619/fable-method/agents-md"><img src="https://agentmods.dev/badge/instructions/sahir619/fable-method/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.03676 | $0.03676 |
| Opus 5.5 | $0.01470 | $0.01470 |
| Sonnet 5.5 | $0.00735 | $0.00735 |
| Haiku 4.5 | $0.00368 | $0.00368 |
Grade A, and why
fable-method AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md - The Fable Method
Portable version for any coding agent or harness (Codex, Cursor, aider, a raw system prompt). Identical method to SKILL.md; paste this file into your agent instructions or drop it at your repo root as AGENTS.md.
A mid-tier model that follows this loop beats a stronger model that free-styles: the quality lives in the structure, the evidence, and the honesty, not in the model. The loop is self-contained. Follow it literally. The steps structure your work, never your output: do not narrate step numbers or step headers in anything the user reads.
Usage
/fable-method <task> full loop on the task (default)
/fable-method plan <task> Steps 0-3 only: classify, define done, gather evidence, deliver the plan, stop
/fable-method audit grade the work already done in this conversation against the loop (see Modes)
/fable-method report rewrite the answer you were about to send per Step 6
Deeper material loads on demand: references/failure-modes.md (symptom to step map for 18 common agent failures), references/examples.md (full worked examples for every ask shape), references/domains/ (domain adapters for non-code work: marketing, research, data analysis, business/ops, finance, legal, design, devops/infrastructure; an adapter changes only the nouns, never the loop, and its minimum evidence set is binding).
Triviality gate (run first). A task is trivial only if ALL of these are true: one file, under ~10 changed lines, no new behavior, and you already know exactly what to change without searching. If trivial: make the change, confirm it with the one obvious check (re-read the changed span, or run the build/lint/command it affects), and report in one or two sentences. Everything else, and anything you are unsure about, gets the full loop.
Fit gate (run next, before Step 0). This loop turns judgment problems into evidence problems whenever the answer is reachable; it cannot supply judgment that lives only in your own head. So first locate where the answer is, and route:
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 124 lines · 3,676 tokens per session scan A 8237d3aea887
fable-method AGENTS.md is an instructions file published in the GitHub repository Sahir619/fable-method (2,304 stars, last pushed 17d ago), licensed MIT. It adds 3,676 tokens to every session, about $0.0147 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.