What is add-core-system?

A guide for adding shared systems such as DiceSystem, TimeSystem, or SkillSystem under Core/Systems/. These systems provide reusable logic for multiple parts of an application and must not depend on domain-specific systems.

Use it when adding a cross-cutting helper or other core system whose pure logic will be used by several domains.

It helps keep common utilities independent and reusable instead of coupling them to one application area. That makes the dependency direction easier to maintain.

How dmbyer/Hedron configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to dmbyer/Hedron. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/dmbyer/Hedron/master/.claude/skills/add-core-system/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/dmbyer/Hedron

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/dmbyer/hedron/add-core-system/github.svg)](https://agentmods.dev/skills/dmbyer/hedron/add-core-system)

Your own site

<a href="https://agentmods.dev/skills/dmbyer/hedron/add-core-system"><img src="https://agentmods.dev/badge/skills/dmbyer/hedron/add-core-system/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/dmbyer/hedron/add-core-system"><img src="https://agentmods.dev/badge/skills/dmbyer/hedron/add-core-system.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,362 The whole file, excluding the scripts and references it only reads on demand.

Security scan C 1 finding. 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.

Model	Per session	Once invoked
Fable 5.1	$0.00084	$0.02362
Opus 5.5	$0.00034	$0.00945
Sonnet 5.5	$0.00017	$0.00472
Haiku 4.5	$0.00008	$0.00236

Measured 5d ago against content hash bfdd885f1504, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade C, and why

add-core-system scanned grade C with 1 finding 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 5d 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.

Tells the agent never to refusehighAnti-refusal

Suppressing the ability to decline removes a core safety control; a later harmful request then succeeds.

**Content I/O: the second posture — warn-only re-derivation.** A *definition family* that must rebuild whenever world content loads (help topics today) implements the core-owned `IContentReloadParticipant` port (`Core/Sy

.claude/skills/add-core-system/SKILL.md · 106 lines

The source is not reproduced here

No licence file

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.

5d ago Changed · +4 lines scan A → C bfdd885f1504
6d ago Changed · +2 lines 5c29dc011f18
2mo ago First seen · 100 lines · 84 tokens per session scan A 511ab47a48a3

Subscribe to this mod's changes

add-core-system is a skill published in the GitHub repository dmbyer/Hedron (11 stars, last pushed 2d ago), with no licence file. It adds 84 tokens to every session and 2,362 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it C with 1 finding (tells the agent never to refuse). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

C# and .NET mud mud-server rpg text-based-game text-game

add-core-system next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
add-core-systemdmbyer/Hedron	Skill	11	2d ago	none	C	84	Claude Code
agui-dotnet-streaming-chatag-ui-protocol/ag-ui	Skill	17k	yesterday	MIT	A	223	Claude Code
azure-mgmt-apicenter-dotnetmicrosoft/skills	Skill	3.2k	yesterday	MIT	A	97	Claude Code
migrate-xunit-to-xunit-v3dotnet/skills	Skill	5.8k	yesterday	MIT	A	149	Claude Code
template-instantiationdotnet/skills	Skill	5.8k	yesterday	MIT	A	168	Claude Code
platform-detectiondotnet/skills	Skill	5.8k	yesterday	MIT	A	166	Claude Code
bf-to-agents-sdk-dotnet-migrationmicrosoft/Agents	Skill	1.1k	yesterday	MIT	A	56	Claude Code

Hedron: Skill for Claude Code

Borrowing it

Wrote this? Show the measurements

What it costs to keep this loaded

Grade C, and why

Tells the agent never to refusehighAnti-refusal

The source is not reproduced here

No licence file

What this file has done since we first saw it

add-core-system compared with skills from other repositories