A guide for adding or splitting event handlers, which coordinate work by calling systems and publishing events. It defines their responsibilities, priority, and subscription setup without putting business rules inside them.

Adding handlers, splitting handlers, routing events, registering subscriptions, and choosing handler priority.

It helps keep event handlers small and prevents domain logic from being mixed into event coordination.

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-handler/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-handler/github.svg)](https://agentmods.dev/skills/dmbyer/hedron/add-handler)

Your own site

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

Per session 66 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,243 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.

Model	Per session	Once invoked
Fable 5.1	$0.00066	$0.01243
Opus 5.5	$0.00026	$0.00497
Sonnet 5.5	$0.00013	$0.00249
Haiku 4.5	$0.00007	$0.00124

Measured 4d ago against content hash d565f23d7dea, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

add-handler 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.

.claude/skills/add-handler/SKILL.md · 71 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.

4d ago Changed d565f23d7dea
2mo ago First seen · 71 lines · 66 tokens per session scan A 82a92b436976

Subscribe to this mod's changes

add-handler is a skill published in the GitHub repository dmbyer/Hedron (11 stars, last pushed 2d ago), with no licence file. It adds 66 tokens to every session and 1,243 once invoked, about $0.0003 per session on Opus 5.5. 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.

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

add-handler next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
add-handlerdmbyer/Hedron	Skill	11	2d ago	none	A	66	Claude Code
azure-maps-search-dotnetmicrosoft/skills	Skill	3.2k	yesterday	MIT	A	91	Claude Code
azure-mgmt-apicenter-dotnetmicrosoft/skills	Skill	3.2k	yesterday	MIT	A	97	Claude Code
azure-ai-voicelive-dotnetmicrosoft/skills	Skill	3.2k	yesterday	MIT	A	92	Claude Code
omnistudio-callable-apex-generateforcedotcom/sf-skills	Skill	1.1k	2d ago	Apache-2.0	A	176	Claude Code, Codex
akka-hosting-actor-patternsAaronontheweb/dotnet-skills	Skill	1.3k	9d ago	MIT	A	51	Claude Code
clean-architecturecodewithmukesh/dotnet-claude-kit	Skill	805	2d ago	MIT	A	75	Claude Code

Hedron: Skill for Claude Code