What is event-sourcing?

A functional TypeScript pattern for event sourcing, where an application stores an append-only history of events and rebuilds current state from that history. It covers decision logic, event stores, read models, projections, versioning, and snapshots.

Use it to implement event-sourced write models, event storage, projections, read models, event version changes, and snapshots.

It preserves what happened instead of storing only the latest state, making past changes available for rebuilding or reviewing application state.

event-sourcing — Skill for Claude Code by citypaul/.dotfiles

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 citypaul/.dotfiles --skill event-sourcing

Clone the repo

git clone --depth 1 https://github.com/citypaul/.dotfiles

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/citypaul/.dotfiles/event-sourcing/github.svg)](https://agentmods.dev/skills/citypaul/.dotfiles/event-sourcing)

Your own site

<a href="https://agentmods.dev/skills/citypaul/.dotfiles/event-sourcing"><img src="https://agentmods.dev/badge/skills/citypaul/.dotfiles/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/citypaul/.dotfiles/event-sourcing"><img src="https://agentmods.dev/badge/skills/citypaul/.dotfiles/event-sourcing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 6,952 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 unknown 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.

Model	Per session	Once invoked
Fable 5.1	$0.00096	$0.06952
Opus 5.5	$0.00038	$0.02781
Sonnet 5.5	$0.00019	$0.01390
Haiku 4.5	$0.00010	$0.00695

Measured 2mo ago against content hash fe4e9301cf53, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

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 2mo 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.

claude/.claude/skills/event-sourcing/SKILL.md · 421 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

9 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.

2mo ago First seen · 421 lines · 96 tokens per session scan A fe4e9301cf53

Subscribe to this mod's changes

event-sourcing is a skill published in the GitHub repository citypaul/.dotfiles (757 stars, last pushed 4d ago), with no licence file. It adds 96 tokens to every session and 6,952 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-08-30.

Backend and APIs Languages TypeScript

event-sourcing next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
event-sourcingcitypaul/.dotfiles	Skill	757	4d ago	none	A	96	Claude Code
stripe-projectse2b-dev/E2B	Skill	15k	yesterday	Apache-2.0	A	51	Claude Code, Codex
nestjs-expertJeffallan/claude-skills	Skill	12k	8d ago	MIT	A	107	Claude Code
chat-sdkvercel-labs/open-agents	Skill	5.9k	2mo ago	MIT	A	191	Claude Code, Codex
nestjsericrisco/rsc-harness	Skill	529	3d ago	MIT	A	81	Claude Code, Codex
azure-web-pubsub-tsbenjaminasterA/antigravity-awesome-skills	Skill	465	yesterday	MIT	A	51	Claude Code, Codex
better-authsecondsky/claude-skills	Skill	247	7d ago	MIT	A	53	Claude Code