event-contract-matrix

event-contract-matrix is a skill for Claude Code, Codex from arch3rPro/dsh-skills. It costs 55 tokens per session (591 once invoked), scanned A, original, MIT.

A documentation practice for tracking which parts of an event-driven system send each event and which parts receive it. Event-driven systems let modules communicate by publishing messages that other modules listen for.

In plain words
What is it for?
It helps document events in pub/sub systems, including events sent by several modules, received by several modules, or sent through an intentional bypass of the usual path.
Why use it?
It prevents event connections from being hidden across scattered code, making changes easier to check and reducing missed listeners or unexpected senders.

Skill for Claude CodeCodex

Written for Claude Code and Codex: shipped in a Claude Code plugin, but also agents/openai.yaml present.

Part of the dsh-skills plugin — 15 skills shipped together

Good fit It helps document events in pub/sub systems, including events sent by several modules, received by several modules, or sent through an intentional bypass of the usual path.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/arch3rpro/dsh-skills/event-contract-matrix
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 arch3rPro/dsh-skills --skill event-contract-matrix
Clone the repo
git clone --depth 1 https://github.com/arch3rPro/dsh-skills

Made for: Claude Code, Codex.

Or install dsh-skills, the plugin that ships this one along with the rest of its 15 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 event-contract-matrix

README.md
[![agentmods](https://agentmods.dev/badge/skills/arch3rpro/dsh-skills/event-contract-matrix/github.svg)](https://agentmods.dev/skills/arch3rpro/dsh-skills/event-contract-matrix)
Your own site
<a href="https://agentmods.dev/skills/arch3rpro/dsh-skills/event-contract-matrix"><img src="https://agentmods.dev/badge/skills/arch3rpro/dsh-skills/event-contract-matrix/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.

agentmods 80×15 button for event-contract-matrix

Your own site · 80×15
<a href="https://agentmods.dev/skills/arch3rpro/dsh-skills/event-contract-matrix"><img src="https://agentmods.dev/badge/skills/arch3rpro/dsh-skills/event-contract-matrix.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 591 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 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 5.1 $0.00055 $0.00591
Opus 5 $0.00028 $0.00296
Sonnet 5 $0.00011 $0.00118
Haiku 4.5 $0.00006 $0.00059

Measured 9d ago against content hash 494c0a152d7f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

event-contract-matrix 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 9d 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/documentation/event-contract-matrix/SKILL.md · 42 lines

How it starts

The opening of the file, as written. The whole thing — 42 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Event Contract Matrix

A discipline for documenting who produces and who consumes each event in an event-driven or pub/sub system. It keeps the event contracts a single source of truth, so a change to a producer or consumer is visible against the whole graph instead of being discovered per call site.

The defining constraint: the matrix records the many-to-many relationship — each event lists its dispatch sites and its listeners — and explicitly notes sites that deliberately bypass the normal emit path. An event contract is not just "this event exists"; it is who can hear it.

What the matrix records

  • One row (or entry) per event, listing:
    • the producer(s) that dispatch it — including any dispatch site that deliberately bypasses the standard emit path (e.g. containment-driven dispatch), so those are visible rather than a hidden surprise;
    • the listener(s) that receive it.
  • The relationship shape: many-to-many, so the matrix is a table of event → producers and event → listeners, not one large implicit graph.

A dense many-to-many relation is best presented as a table rather than a sprawling graph — one event per row, producers and listeners as columns.

Keeping it a single source of truth

  • Update the matrix in the same change that changes an event contract — a new event, a new producer, a new listener, or a new bypass site. Do not let the matrix drift from the code.
  • Treat the matrix as the contract's home. Where a contract is defined, link to the matrix; do not restate the producer/listener list in multiple places.
  • Review it like a contract. When a dispatch or listen site changes, verify the matrix still matches before merging.

Workflow

  1. Enumerate the events that cross module boundaries.
  2. For each event, record its producers and listeners — including bypass sites.
  3. Choose the presentation — a table for many-to-many relations, kept dense and readable.
  4. Update it with each contract change in the same change; link from the contract's definition.
  5. Verify the matrix matches the code before merging.

Read the full file on GitHub · 42 lines

Files

What ships with it

1 file 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.

  1. 9d ago First seen · 42 lines · 55 tokens per session scan A 494c0a152d7f

Subscribe to this mod's changes

event-contract-matrix is a skill published in the GitHub repository arch3rPro/dsh-skills (4 stars, last pushed 22d ago), licensed MIT. It adds 55 tokens to every session and 591 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 2026-08-31.