lean-debt

lean-debt is a command for coding agents from MilindGaharwar/fettle. It costs 0 tokens per session (186 once invoked), scanned A, original, Apache-2.0.

A command that reports deliberate simplifications marked with fettle:lean comments and the conditions for revisiting them.

In plain words
What is it for?
Find lean-debt markers, review their upgrade triggers, and identify simplifications that may need reconsideration as the project grows.
Why use it?
It helps teams remember where code was intentionally kept simple and avoids unnecessary abstraction. Missing upgrade conditions are flagged as possible maintenance risks.

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/lean-debt
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 lean-debt

README.md
[![agentmods](https://agentmods.dev/badge/commands/milindgaharwar/fettle/lean-debt.svg)](https://agentmods.dev/commands/milindgaharwar/fettle/lean-debt)
Your own site
<a href="https://agentmods.dev/commands/milindgaharwar/fettle/lean-debt"><img src="https://agentmods.dev/badge/commands/milindgaharwar/fettle/lean-debt.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 186 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 $0.00000 $0.00186
Opus 5 $0.00000 $0.00093
Sonnet 5 $0.00000 $0.00037
Haiku 4.5 $0.00000 $0.00019

Measured 3d ago against content hash 30977756786d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

lean-debt 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.

commands/lean-debt.md · 31 lines

What it actually says

/fettle:lean-debt

Report all fettle:lean: markers in the project — deliberate simplifications and their upgrade triggers.

Usage

python3 -m fettle.lean_debt

Convention

Mark intentional simplifications with:

# fettle:lean: <what>, upgrade when: <trigger>

Examples:

# fettle:lean: flat dict dispatch, upgrade when: >5 handlers
# fettle:lean: inline validation, upgrade when: shared across 3+ files
// fettle:lean: manual retry, upgrade when: need backoff/jitter

Markers without "upgrade when:" are flagged as rot risks.

Purpose

Answers: "Where did we choose simple intentionally, and when should we reconsider?" Prevents future agents from over-abstracting code that was deliberately kept lean.

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 · 31 lines · 0 tokens per session scan A 30977756786d

Subscribe to this mod's changes

lean-debt is a command published in the GitHub repository MilindGaharwar/fettle (2 stars, last pushed today), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 186 tokens. 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.