event-storming

event-storming is a skill for Codex from BlacklineCloud/agent-skills. It costs 78 tokens per session (551 once invoked), scanned A, original, MIT.

A facilitated EventStorming workflow for discovering a business domain and designing software around it. EventStorming is a workshop method for mapping business events, actions, rules, people, and systems.

In plain words
What is it for?
Use it to run or document Big Picture, Process Modelling, Software Design, or document-first EventStorming and produce a checked handoff.
Why use it?
It helps teams understand how the business works before choosing implementation details or arguing over software structure.

Skill for Codex

Written for Codex: agents/openai.yaml present.

Good fit Use it to run or document Big Picture, Process Modelling, Software Design, or document-first EventStorming and produce a checked handoff.

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Install with agentmods
npx agentmods add skills/blacklinecloud/agent-skills/event-storming
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 BlacklineCloud/agent-skills --skill event-storming
Clone the repo
git clone --depth 1 https://github.com/BlacklineCloud/agent-skills

Made for: Codex.

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-storming

README.md
[![agentmods](https://agentmods.dev/badge/skills/blacklinecloud/agent-skills/event-storming.svg)](https://agentmods.dev/skills/blacklinecloud/agent-skills/event-storming)
Your own site
<a href="https://agentmods.dev/skills/blacklinecloud/agent-skills/event-storming"><img src="https://agentmods.dev/badge/skills/blacklinecloud/agent-skills/event-storming.svg" alt="Measured on agentmods" height="20"></a>
Per session 78 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 551 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 $0.00078 $0.00551
Opus 5 $0.00039 $0.00275
Sonnet 5 $0.00016 $0.00110
Haiku 4.5 $0.00008 $0.00055

Measured 8d ago against content hash 84578480d653, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

event-storming 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 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/validate_output.py), 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.

skills/event-storming/SKILL.md · 40 lines

How it starts

The opening of the file, as written. The whole thing — 40 lines — stays where its author put it; the contents beside it link to each section on GitHub.

EventStorming

Use this skill to facilitate EventStorming for domain discovery and DDD-first software design across Big Picture, Process Modelling, Software Design, and document-first pre-work. Treat SKILL.md as the entrypoint: choose the format, collect minimum context, load only the references needed for the chosen run, and end with one canonical markdown handoff.

Workflow

  1. Choose the format or document-first pre-work based on the user's goal and the quality of available evidence.
  2. Collect minimum context:
    • business scope and target decision
    • participants or source documents
    • major actors and systems
    • main pain points, open questions, and constraints
  3. Load only the reference files needed for the chosen format.
  4. Model the business flow before implementation details and keep the discussion domain-first.
  5. Produce one canonical markdown handoff and run python3 scripts/validate_output.py <path-to-output> before treating it as final.

Guardrails

  • Discovery before design.
  • Use business language first.
  • Write domain events in past tense.
  • Model commands as intentional business actions.
  • Model policies as repeatable reactions in the form Whenever X, then Y.
  • Surface uncertainty explicitly with Fact, Assumption, Open question, Risk, and Decision.
  • Do not jump to APIs, schemas, or implementation structure before the business flow is coherent.

Reference Routing

Read the full file on GitHub · 40 lines

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. 8d ago First seen · 40 lines · 78 tokens per session scan A 84578480d653

Subscribe to this mod's changes

event-storming is a skill published in the GitHub repository BlacklineCloud/agent-skills (1 stars, last pushed yesterday), licensed MIT. It adds 78 tokens to every session and 551 once invoked, about $0.0004 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.