Output format·Databases

Event Store Design

Design and implement event stores for event-sourced systems.

You say
Install this skill Read the source first Free Written by wshobson · unverified publisher
Context cost
3.9k tokensestimated from the bundle, loaded when it triggers
Bundle
2 files · 15.5 kBtext throughout, nothing executable
Licence
MITfree to use
Last change
no release on file
Servers it uses
Noneruns standalone

What it does

Design and implement event stores for event-sourced systems. Use when building event sourcing infrastructure, choosing event store technologies, or implementing event persistence patterns.

Installed, it changes the agent in these ways.

What this skill changes about the agent is not written down here yet. The listing was collected from its source, and the description is in its own SKILL.md.

Output format

Produces one artefact, exactly shaped.

database
Filed under

Databases

The skill itself

This is the whole product. A skill is instructions the model reads, so there is nothing behind the listing you cannot see first — the front matter loads with every session, and the body below it loads when the skill triggers.

SKILL.md4.1 kB · 81 lines
--- name: event-store-design description: Design and implement event stores for event-sourced systems. Use when building event sourcing infrastructure, choosing event store technologies, or implementing event persistence patterns. ---
6# Event Store Design
7
8Comprehensive guide to designing event stores for event-sourced applications.
9
10## When to Use This Skill
11
12- Designing event sourcing infrastructure
13- Choosing between event store technologies
14- Implementing custom event stores
15- Optimizing event storage and retrieval
16- Setting up event store schemas
17- Planning for event store scaling
18
19## Core Concepts
20
21### 1. Event Store Architecture
22
23```
24┌─────────────────────────────────────────────────────┐
25│ Event Store │
26├─────────────────────────────────────────────────────┤
27│ ┌─────────────┐ ┌─────────────┐ ┌─────────────┐ │
28│ │ Stream 1 │ │ Stream 2 │ │ Stream 3 │ │
29│ │ (Aggregate) │ │ (Aggregate) │ │ (Aggregate) │ │
30│ ├─────────────┤ ├─────────────┤ ├─────────────┤ │
31│ │ Event 1 │ │ Event 1 │ │ Event 1 │ │
32│ │ Event 2 │ │ Event 2 │ │ Event 2 │ │
33│ │ Event 3 │ │ ... │ │ Event 3 │ │
34│ │ ... │ │ │ │ Event 4 │ │
35│ └─────────────┘ └─────────────┘ └─────────────┘ │
36├─────────────────────────────────────────────────────┤
37│ Global Position: 1 → 2 → 3 → 4 → 5 → 6 → ... │
38└─────────────────────────────────────────────────────┘
39```
40
41### 2. Event Store Requirements
42
43| Requirement | Description |
44| ----------------- | ---------------------------------- |
45| **Append-only** | Events are immutable, only appends |
46| **Ordered** | Per-stream and global ordering |
47| **Versioned** | Optimistic concurrency control |
48| **Subscriptions** | Real-time event notifications |
49| **Idempotent** | Handle duplicate writes safely |
50
51## Technology Comparison
52
53| Technology | Best For | Limitations |
54| ---------------- | ------------------------- | -------------------------------- |
55| **EventStoreDB** | Pure event sourcing | Single-purpose |
56| **PostgreSQL** | Existing Postgres stack | Manual implementation |
57| **Kafka** | High-throughput streaming | Not ideal for per-stream queries |
58| **DynamoDB** | Serverless, AWS-native | Query limitations |
59| **Marten** | .NET ecosystems | .NET specific |
60
61## Templates and detailed worked examples
62
63Full template library and detailed worked examples live in references/details.md. Read that file when you need the concrete templates.
64
65## Best Practices
66
67### Do's
68
69- **Use stream IDs that include aggregate type** - Order-{uuid}
70- **Include correlation/causation IDs** - For tracing
71- **Version events from day one** - Plan for schema evolution
72- **Implement idempotency** - Use event IDs for deduplication
73- **Index appropriately** - For your query patterns
74
75### Don'ts
76
77- **Don't update or delete events** - They're immutable facts
78- **Don't store large payloads** - Keep events small
79- **Don't skip optimistic concurrency** - Prevents data corruption
80- **Don't ignore backpressure** - Handle slow consumers
81
In the file
SKILL.md442 words
Files2
LicenceMIT
Why you can read it

Nothing in a skill executes. The client loads the text and the model follows it, so a skill can be audited the way a runbook is — by reading it.

What it costs in context

Skills are not billed by the call. They are paid for in context: every token the instructions occupy is a token your code, your diff and your conversation cannot use. Here is what this one takes and when it takes it.

≈60
always loaded
The name and description, so the model knows the skill exists and when to reach for it.
3,815
on trigger
The instruction body and 1 supporting file, read only when the skill fires.
1.9%
of a 200k window
Ten skills this size would take about 19% of the window before you open a file.
050k100k150k200k context window

3.9k tokens, estimated from the bundle at four bytes to the token, held for the rest of the session once it triggers. Middling. Fine to keep on in a project where you use it weekly, worth unloading in one where you never do.

Servers bill, skills cost

A server charges by the month. A skill charges once per session, in context, and then keeps charging it for as long as the session lives.

Before and after

The same question, put to the same model twice: once as it comes, and once with these instructions loaded.

No worked example has been published for this skill yet.

Adoption
Installsnone yet
Ratingno reviews yet

The procedure it runs

The procedure has not been published here. It is in the skill’s own SKILL.md, which its author has not sent to the marketplace yet.

Prose, not code

These steps are written for a model to follow, not executed by a runtime. It can still be told to skip one, and it will say so when it does.

Servers it uses

None. This skill calls no MCP servers at all.

Everything it needs is in the instructions, so it works in a project with nothing connected — the model reads the file and changes how it works with what it can already reach.

It writes no files and reaches no network. All it changes is how the model reasons and writes.

What it asks for
Writes filesno
Network accessno

Read from the allowed-tools line of this skill’s own SKILL.md. A skill grants no permissions of its own — it can only ask for tools your client already has.

What it will not do

Every skill is narrow, and the useful ones say where they stop. These are the jobs this one is the wrong tool for.

What this skill is not for has not been published here. Nothing is implied by that: it is a section the author has not filled in.

What is in the bundle

2 files, 15.5 kB on disk. A bundle is text throughout: the instructions the model reads, plus the templates it fills in.

  • SKILL.md4.1 kB
  • references/details.md11.4 kB
What is not in it

No dependencies and nothing executable: a skill is text the agent reads, so the bundle is 2 files you can review in full before installing. The MIT licence covers the templates and examples as well as the instructions.

Install

Installing copies the bundle into your project. Nothing runs at install time — the files sit on disk until the model reads them.

# Event Store Design · 3.9k tokens when loaded npx mcprush@latest skill add wshobson/event-store-design

Writes to .claude/skills/event-store-design/ in the current project. Add --global to put it in your home directory instead, for every project.

Which clients pick it up on their own

A skill is a folder of text. A client with a skills folder reads it without being told; everywhere else the same text works, it is just handed to the model rather than found.

Claude Code.claude/skills/
Claude Desktop
ChatGPT
Cursor.cursor/skills/
VS Code.github/skills/
Codex CLI.agents/skills/
Gemini CLI.gemini/skills/
Grok.grok/skills/
Zed.agents/skills/
Windsurf.windsurf/skills/
Agent SDK.claude/skills/
HTTP / API
This release
Versionnot versioned
Publishedno release date on file
PriceFree
Referencewshobson/event-store-design

Versions

Its author publishes no version number, so there is nothing here to pin to: what you install is the folder as it stands today. Instructions change more often than APIs do — a skill can be rewritten entirely without anything it depends on moving.

v
  • No earlier releases have been published to the marketplace.
Pinning

Nothing to pin to: this skill carries no version number of its own. What you install is what the folder holds on the day you install it.

Reviews

no reviews yet · no installs yet

Nobody has reviewed this skill yet. The rating is the mean of the reviews written here, so there is none until somebody writes the first.

Who can post

Only accounts that have had the skill installed for fourteen days, so a review is written after living with it rather than after reading it. Publishers may reply once.

Publisher
Servers0