fettle-explain

fettle-explain is a command for coding agents from MilindGaharwar/fettle. It costs 12 tokens per session (142 once invoked), scanned A, original, Apache-2.0.

A project command that explains why Fettle blocked or warned about the most recent edit.

In plain words
What is it for?
Use it to inspect the hook, file, checker, specific violations, and suggested fixes or suppressions behind the latest warning.
Why use it?
It separates actual code-quality findings from infrastructure or tool problems and shows what caused the decision.

Command

Part of the fettle plugin — 34 commands, 4 hooks shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/milindgaharwar/fettle/fettle-explain
Clone the repo
git clone --depth 1 https://github.com/MilindGaharwar/fettle

Or install fettle, the plugin that ships this one along with the rest of its 34 commands, 4 hooks.

Wrote 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.

agentmods badge for fettle-explain

README.md
[![agentmods](https://agentmods.dev/badge/commands/milindgaharwar/fettle/fettle-explain.svg)](https://agentmods.dev/commands/milindgaharwar/fettle/fettle-explain)
Your own site
<a href="https://agentmods.dev/commands/milindgaharwar/fettle/fettle-explain"><img src="https://agentmods.dev/badge/commands/milindgaharwar/fettle/fettle-explain.svg" alt="Measured on agentmods" height="20"></a>
Per session 12 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 142 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00012 $0.00142
Opus 5 $0.00006 $0.00071
Sonnet 5 $0.00002 $0.00028
Haiku 4.5 $0.00001 $0.00014

Measured 3d ago against content hash b3a8f740ee60, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fettle-explain 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 3d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • explain — 97% identical, 5 lines differ
.opencode/commands/fettle-explain.md · 26 lines

What it actually says

/fettle:explain

Explain why Fettle blocked or warned about the last edit.

Usage

When the user invokes /fettle:explain:

fettle explain

Shows for each decision:

  • Which hook ran (PreToolUse, PostToolUse, Stop)
  • Which file was checked
  • Which tool found the issue (ruff, semgrep, or infrastructure error)
  • The specific violation(s)
  • How to fix or suppress

Helps users understand: "Was this a code quality issue or a Fettle bug?"

Changes

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.

  1. 3d ago First seen · 26 lines · 12 tokens per session scan A b3a8f740ee60

Subscribe to this mod's changes

fettle-explain is a command published in the GitHub repository MilindGaharwar/fettle (2 stars, last pushed 5d ago), licensed Apache-2.0. It adds 12 tokens to every session and 142 once invoked, about $0.0001 per session on Opus 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 2026-08-31.