decompose-gates

decompose-gates is a skill for Claude Code, Codex from happier-dev/happier. It costs 58 tokens per session (1,151 once invoked), scanned A, original, MIT.

A planning method for breaking a difficult task into independently checkable claims, each with a clear test or verification step. It orders the work around the assumptions and risks most likely to cause failure.

In plain words
What is it for?
Use it to plan complex engineering work, define subtask briefs, choose verification steps, and sequence work by risk and information gained.
Why use it?
It prevents large tasks from being treated as one unverified block and exposes risky assumptions early.

Skill for Claude CodeCodex

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 skills/happier-dev/happier/decompose-gates
Any agent
npx skills add happier-dev/happier --skill decompose-gates
Clone the repo
git clone --depth 1 https://github.com/happier-dev/happier

Made for: Claude Code, Codex.

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 decompose-gates

README.md
[![agentmods](https://agentmods.dev/badge/skills/happier-dev/happier/decompose-gates.svg)](https://agentmods.dev/skills/happier-dev/happier/decompose-gates)
Your own site
<a href="https://agentmods.dev/skills/happier-dev/happier/decompose-gates"><img src="https://agentmods.dev/badge/skills/happier-dev/happier/decompose-gates.svg" alt="Measured on agentmods" height="20"></a>
Per session 58 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,151 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 $0.00058 $0.01151
Opus 5 $0.00029 $0.00575
Sonnet 5 $0.00012 $0.00230
Haiku 4.5 $0.00006 $0.00115

Measured 4d ago against content hash a9e303df8088, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

decompose-gates 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 4d 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.

skills/decompose-gates/SKILL.md · 40 lines

How it starts

The opening of the file, as written. The whole thing — 40 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Decompose With Gates

Turn a hard task into pieces that can each pass or fail on their own, ordered so the riskiest assumption is tested first. Full doctrine: docs/agent-craft.md §2–§3.

Procedure

  1. Split along verification boundaries, not implementation convenience. Each piece must have its own pass/fail check that does not depend on the other pieces being right. If checking B assumes A is correct, A+B is one piece, not two.
  2. State each piece as a falsifiable claim, not a task. "The watermark advances only after server ack" (checkable) — not "update watermark logic" (a task). Attach to each claim the concrete check that decides it: a test slice, a log observation, a live replay, a measurement.
  3. Name the risk spots before sequencing. Write the two or three "if I'm wrong anywhere, it's here" spots — silent failure modes, irreversible steps, boring mechanical stretches — and design a specific verification for each. Generic suite runs are uniform effort against non-uniform risk.
  4. Order by information yield. Test first the smallest shared assumption whose failure would invalidate repeated downstream units. This gates only dependent replication: keep independent work moving and expand the rolling window as soon as the assumption holds. Skip the ramp when prior evidence or a deterministic tool already proves the unit shape.
  5. Relay dependency context, not only order. State the upstream contract and evidence each piece consumes. Those assumptions are themselves claims to check; most integration failures live at the interfaces.
  6. Right-size. A piece owns a whole responsibility end to end: analysis, change, tests, validation. Too small to fail meaningfully is overhead — micro-slicing (one-boolean extractions) provably grew the god-files it was meant to shrink. Too big to check independently is not decomposed yet.
  7. Prefer consumed verticals over horizontal spines. The first implementation slice should connect a real entry point through its canonical owner to an observable outcome. Do not split protocol/schema/producer/consumer into weeks of dormant layers whose correctness can only be known after activation. When compatibility forces phases, each phase names its active reader/consumer and removal condition.
  8. Firewall live-path corrections. If gated or dormant work exposes a live dispatch, lifecycle, persistence, migration, or startup defect, handle that correction as its own complete vertical at the live owner. Do not partially activate the dormant design to fix the production path.

Read the full file on GitHub · 40 lines

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. 4d ago First seen · 40 lines · 58 tokens per session scan A a9e303df8088

Subscribe to this mod's changes

decompose-gates is a skill published in the GitHub repository happier-dev/happier (1,615 stars, last pushed today), licensed MIT. It adds 58 tokens to every session and 1,151 once invoked, about $0.0003 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 2026-08-30.

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