architecture-paradigm-cqrs-es

architecture-paradigm-cqrs-es is a skill for Claude Code from athola/claude-night-market. It costs 39 tokens per session (953 once invoked), scanned A, original, MIT.

A software design approach that separates changing data from the operations that read it, while recording every state change as a permanent event. The event history can be used to rebuild current views or inspect past states.

In plain words
What is it for?
Use it to design command and query flows, event histories, audit trails, rebuildable data views, and systems with complex business rules.
Why use it?
It provides a detailed audit trail and supports systems where reading and writing have different performance or scaling needs. It also makes historical queries and rebuilding data views possible.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions Claude Code.

Part of the archetypes plugin — 15 skills shipped together

Good fit Use it to design command and query flows, event histories, audit trails, rebuildable data views, and systems with complex business rules.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/athola/claude-night-market/architecture-paradigm-cqrs-es
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 athola/claude-night-market --skill architecture-paradigm-cqrs-es
Clone the repo
git clone --depth 1 https://github.com/athola/claude-night-market

Made for: Claude Code.

Or install archetypes, 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 architecture-paradigm-cqrs-es

README.md
[![agentmods](https://agentmods.dev/badge/skills/athola/claude-night-market/architecture-paradigm-cqrs-es/github.svg)](https://agentmods.dev/skills/athola/claude-night-market/architecture-paradigm-cqrs-es)
Your own site
<a href="https://agentmods.dev/skills/athola/claude-night-market/architecture-paradigm-cqrs-es"><img src="https://agentmods.dev/badge/skills/athola/claude-night-market/architecture-paradigm-cqrs-es/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 architecture-paradigm-cqrs-es

Your own site · 80×15
<a href="https://agentmods.dev/skills/athola/claude-night-market/architecture-paradigm-cqrs-es"><img src="https://agentmods.dev/badge/skills/athola/claude-night-market/architecture-paradigm-cqrs-es.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 953 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00039 $0.00953
Opus 5 $0.00019 $0.00477
Sonnet 5 $0.00008 $0.00191
Haiku 4.5 $0.00004 $0.00095

Measured 9d ago against content hash 3817d275afb7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

architecture-paradigm-cqrs-es 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.

plugins/archetypes/skills/architecture-paradigm-cqrs-es/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The CQRS and Event Sourcing Paradigm

When To Use

  • Designing event-sourced systems with complex domain logic
  • Systems requiring full audit trails of state changes

When NOT To Use

  • Simple CRUD applications without complex domain logic
  • Small projects where event sourcing adds unnecessary complexity

When to Employ This Paradigm

  • When read and write workloads have vastly different performance characteristics or scaling requirements.
  • When all business events must be captured in a durable, immutable history or audit trail.
  • When a business needs to rebuild projections of data or support temporal queries (e.g., "What did the state of this entity look like yesterday?").

Adoption Steps

  1. Identify Aggregates: Following Domain-Driven Design principles, specify the bounded contexts and the business invariants that each command must enforce on an aggregate.
  2. Model Commands and Events: Define the schemas and validation rules for all commands and the events they produce. Document a clear strategy for versioning and schema evolution.
  3. Implement the Write Side (Command Side): Command handlers are responsible for loading an aggregate's event stream, executing business logic, and atomically appending new events to the stream.
  4. Build Projections to the Read Side: Create separate read models (projections) that are fed by subscriptions to the event stream. Implement back-pressure and retry policies for these subscriptions.
  5. validate Full Observability: Implement detailed logging that includes event IDs, sequence numbers, and metrics for tracking the lag time of each projection.

Key Deliverables

  • An Architecture Decision Record (ADR) detailing the aggregates, the chosen event store technology, the projection strategy, and the expected data consistency model (e.g., eventual consistency SLAs).
  • A suite of tests for command handlers that use in-memory event streams, complemented by integration tests for the projections.
  • Operational tooling for replaying events, taking state snapshots for performance, and managing schema migrations.

Read the full file on GitHub · 85 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. 9d ago First seen · 85 lines · 39 tokens per session scan A 3817d275afb7

Subscribe to this mod's changes

architecture-paradigm-cqrs-es is a skill published in the GitHub repository athola/claude-night-market (337 stars, last pushed yesterday), licensed MIT. It adds 39 tokens to every session and 953 once invoked, about $0.0002 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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