build-rule

build-rule is a skill for Claude Code from GobbyAI/gobby. It costs 39 tokens per session (3,553 once invoked), scanned A, original, no licence file.

A guided way to write Gobby rule definitions in YAML, a text format for structured settings.

In plain words
What is it for?
Use it to create, write, add, or enforce Gobby rules.
Why use it?
It helps turn a request to create or enforce a rule into a defined process, instead of leaving the rule format unclear.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the code-navigator plugin — 43 skills shipped together

Good fit Use it to create, write, add, or enforce Gobby rules.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/gobbyai/gobby/build-rule
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.

Any agent
npx skills add GobbyAI/gobby --skill build-rule
Clone the repo
git clone --depth 1 https://github.com/GobbyAI/gobby

Made for: Claude Code.

Or install code-navigator, the plugin that ships this one along with the rest of its 43 skills.

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 build-rule

README.md
[![agentmods](https://agentmods.dev/badge/skills/gobbyai/gobby/build-rule.svg)](https://agentmods.dev/skills/gobbyai/gobby/build-rule)
Your own site
<a href="https://agentmods.dev/skills/gobbyai/gobby/build-rule"><img src="https://agentmods.dev/badge/skills/gobbyai/gobby/build-rule.svg" alt="Measured on agentmods" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,553 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00039 $0.03553
Opus 5 $0.00019 $0.01776
Sonnet 5 $0.00008 $0.00711
Haiku 4.5 $0.00004 $0.00355

Measured 7d ago against content hash 7a646a9b5057, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

build-rule 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 7d 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.

src/gobby/install/shared/skills/build-rule/SKILL.md · 472 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 7d ago First seen · 472 lines · 39 tokens per session scan A 7a646a9b5057

Subscribe to this mod's changes

build-rule is a skill published in the GitHub repository GobbyAI/gobby (19 stars, last pushed 5d ago), with no licence file. It adds 39 tokens to every session and 3,553 once invoked, about $0.0002 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.