Event Sourcing Testing

Event Sourcing Testing is a skill for Claude Code, Codex from PramodDutta/qaskills. It costs 27 tokens per session (823 once invoked), scanned A, a copy of axe-core Accessibility Automation, MIT.

A guide to testing event sourcing, a design where application changes are saved as a sequence of events and current views are rebuilt from them.

In plain words
What is it for?
Use it to test event stores, projections, saga workflows, and support for older event versions.
Why use it?
It helps detect invalid stored events, incorrect rebuilt views, broken workflows, and compatibility problems when event formats change.

Skill for Claude CodeCodex

Which agent this was written for is unclear — built for aider. Also seen: mentions Codex; built for aider.

Good fit Use it to test event stores, projections, saga workflows, and support for older event versions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/pramoddutta/qaskills/event-sourcing-testing
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 PramodDutta/qaskills --skill event-sourcing-testing
Clone the repo
git clone --depth 1 https://github.com/PramodDutta/qaskills

Made for: Claude Code, 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 Sourcing Testing

README.md
[![agentmods](https://agentmods.dev/badge/skills/pramoddutta/qaskills/event-sourcing-testing.svg)](https://agentmods.dev/skills/pramoddutta/qaskills/event-sourcing-testing)
Your own site
<a href="https://agentmods.dev/skills/pramoddutta/qaskills/event-sourcing-testing"><img src="https://agentmods.dev/badge/skills/pramoddutta/qaskills/event-sourcing-testing.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 823 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 86% copy Near-identical to another mod 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 $0.00027 $0.00823
Opus 5 $0.00014 $0.00411
Sonnet 5 $0.00005 $0.00165
Haiku 4.5 $0.00003 $0.00082

Measured 4d ago against content hash 32ab3892b784, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

Event Sourcing Testing 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.

Origin

This is a copy

86% identical to axe-core Accessibility Automation — 44 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

seed-skills/event-sourcing-testing/SKILL.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Event Sourcing Testing

You are an expert QA engineer specializing in event sourcing testing. When the user asks you to write, review, debug, or set up event-sourcing related tests or configurations, follow these detailed instructions.

Core Principles

  1. Quality First — Ensure all event-sourcing implementations follow industry best practices and produce reliable, maintainable results.
  2. Defense in Depth — Apply multiple layers of verification to catch issues at different stages of the development lifecycle.
  3. Actionable Results — Every test or check should produce clear, actionable output that developers can act on immediately.
  4. Automation — Prefer automated approaches that integrate seamlessly into CI/CD pipelines for continuous verification.
  5. Documentation — Ensure all event-sourcing configurations and test patterns are well-documented for team understanding.

When to Use This Skill

  • When setting up event-sourcing for a new or existing project
  • When reviewing or improving existing event-sourcing implementations
  • When debugging failures related to event-sourcing
  • When integrating event-sourcing into CI/CD pipelines
  • When training team members on event-sourcing best practices

Implementation Guide

Setup & Configuration

When setting up event-sourcing, follow these steps:

  1. Assess the project — Understand the tech stack (typescript, java, csharp) and existing test infrastructure
  2. Choose the right tools — Select appropriate event-sourcing tools based on project requirements
  3. Configure the environment — Set up necessary configuration files and dependencies
  4. Write initial tests — Start with critical paths and expand coverage gradually
  5. Integrate with CI/CD — Ensure tests run automatically on every code change

Best Practices

  • Keep tests focused — Each test should verify one specific behavior or requirement
  • Use descriptive names — Test names should clearly describe what is being verified
  • Maintain test independence — Tests should not depend on execution order or shared state
  • Handle async operations — Properly await async operations and use appropriate timeouts
  • Clean up resources — Ensure test resources are properly cleaned up after execution

Read the full file on GitHub · 89 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. 4d ago First seen · 89 lines · 27 tokens per session scan A 32ab3892b784

Subscribe to this mod's changes

Event Sourcing Testing is a skill published in the GitHub repository PramodDutta/qaskills (218 stars, last pushed 8d ago), licensed MIT. It adds 27 tokens to every session and 823 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to axe-core Accessibility Automation, differing in 44 lines, and is treated as a copy.

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