A collection of reusable implementation patterns that can be applied automatically when a task matches their context. The description does not specify which patterns it contains.

Use it for backend work when an existing pattern matches the request.

It is intended to avoid repeating the same implementation guidance for recurring tasks.

backend — Skill by RublerubitZ

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/rublerubitz/duing/backend

Any agent

npx skills add RublerubitZ/duing --skill backend

Clone the repo

git clone --depth 1 https://github.com/RublerubitZ/duing

Made for: Claude Code, Codex.

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,490 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin unknown 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.

Model	Per session	Once invoked
Fable 5	$0.00000	$0.02490
Opus 5	$0.00000	$0.01245
Sonnet 5	$0.00000	$0.00498
Haiku 4.5	$0.00000	$0.00249

Measured 2d ago against content hash b5f118527e91, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

backend 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 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (gradlew.bat), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

backend/SKILL.md · 290 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

60 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

2d ago First seen · 290 lines · 0 tokens per session scan A b5f118527e91

Subscribe to this mod's changes

backend is a skill published in the GitHub repository RublerubitZ/duing (2 stars, last pushed 2d ago), with no licence file. It costs nothing until one of its globs matches a file; then it loads 2,490 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.

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