cqrs-event-sourcing

cqrs-event-sourcing is a skill for Claude Code from ivegamsft/basecoat. It costs 90 tokens per session (341 once invoked), scanned A, original, MIT.

A set of guidance for designing CQRS and event sourcing systems. CQRS separates changing data from reading it, while event sourcing records changes as a history of events.

In plain words
What is it for?
Use it to plan command handlers, event stores, read models, event replay, snapshots, and saga-based workflows in distributed services.
Why use it?
It helps when a system needs a detailed audit trail, separate scaling for reads and writes, or several views of the same data. It also explains when these patterns would add unnecessary complexity.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to plan command handlers, event stores, read models, event replay, snapshots, and saga-based workflows in distributed services.

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Install with agentmods
npx agentmods add skills/ivegamsft/basecoat/cqrs-event-sourcing
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 ivegamsft/basecoat --skill cqrs-event-sourcing
Clone the repo
git clone --depth 1 https://github.com/ivegamsft/basecoat

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.

agentmods badge for cqrs-event-sourcing

README.md
[![agentmods](https://agentmods.dev/badge/skills/ivegamsft/basecoat/cqrs-event-sourcing/github.svg)](https://agentmods.dev/skills/ivegamsft/basecoat/cqrs-event-sourcing)
Your own site
<a href="https://agentmods.dev/skills/ivegamsft/basecoat/cqrs-event-sourcing"><img src="https://agentmods.dev/badge/skills/ivegamsft/basecoat/cqrs-event-sourcing/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 cqrs-event-sourcing

Your own site · 80×15
<a href="https://agentmods.dev/skills/ivegamsft/basecoat/cqrs-event-sourcing"><img src="https://agentmods.dev/badge/skills/ivegamsft/basecoat/cqrs-event-sourcing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 90 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 341 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 $0.00090 $0.00341
Opus 5 $0.00045 $0.00170
Sonnet 5 $0.00018 $0.00068
Haiku 4.5 $0.00009 $0.00034

Measured 8d ago against content hash a83e73fba989, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

cqrs-event-sourcing 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.

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/cqrs-event-sourcing/SKILL.md · 38 lines

What it actually says

CQRS & Event Sourcing Patterns

Patterns for implementing CQRS and Event Sourcing in distributed systems.

Quick Navigation

Reference Contents
references/command-side.md Commands, command handlers, aggregate design
references/event-sourcing.md Event store, aggregate reconstruction, snapshots, versioning
references/read-side.md Queries, read models, event subscribers, eventual consistency
references/sagas-operations.md Saga pattern, event replay, monitoring, disaster recovery

Core Flow

User → Command → Handler → Event Store → Events → Event Bus
                                                       ↓
                                               Event Handlers → Read Models → User

When to Use

Use when an audit trail, independent read/write scaling, or multiple read-optimized views are needed. Avoid for simple CRUD with uniform load.

Files

What ships with it

5 files 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. 8d ago First seen · 38 lines · 90 tokens per session scan A a83e73fba989

Subscribe to this mod's changes

cqrs-event-sourcing is a skill published in the GitHub repository ivegamsft/basecoat (4 stars, last pushed yesterday), licensed MIT. It adds 90 tokens to every session and 341 once invoked, about $0.0005 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 2026-09-03.

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