Evolutionary Modular Architecture
tech-leads-club/agent-skills
Guides design of modular-monolith platforms with DDD, flat-by-aggregate modules, anti-corruption layers, outbox events and resilience, plus an architecture document with SVG diagrams.
Event sourcing patterns for functional TypeScript — persist state as an append-only log of past events and rebuild it by folding them.
Install Event Sourcing
$ npx skills add citypaul/.dotfiles --skill event-sourcing -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install citypaul/.dotfiles event-sourcing --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .claude/skills && cp -r skills-src/claude/.claude/skills/event-sourcing .claude/skills/event-sourcing && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "event-sourcing" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/event-sourcing into .claude/skills/event-sourcing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "event-sourcing", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/event-sourcingType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add citypaul/.dotfiles --skill event-sourcing -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install citypaul/.dotfiles event-sourcing --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .agents/skills && cp -r skills-src/claude/.claude/skills/event-sourcing .agents/skills/event-sourcing && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "event-sourcing" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/event-sourcing into .agents/skills/event-sourcing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "event-sourcing", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add citypaul/.dotfiles --skill event-sourcing -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install citypaul/.dotfiles event-sourcing --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/claude/.claude/skills/event-sourcing .cursor/skills/event-sourcing && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "event-sourcing" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/event-sourcing into .cursor/skills/event-sourcing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "event-sourcing", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/citypaul/.dotfiles.git --path claude/.claude/skills/event-sourcing--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add citypaul/.dotfiles --skill event-sourcing -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install citypaul/.dotfiles event-sourcing --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/claude/.claude/skills/event-sourcing .gemini/skills/event-sourcing && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "event-sourcing" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/event-sourcing into .gemini/skills/event-sourcing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "event-sourcing", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install citypaul/.dotfiles event-sourcingInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add citypaul/.dotfiles --skill event-sourcing -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .github/skills && cp -r skills-src/claude/.claude/skills/event-sourcing .github/skills/event-sourcing && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "event-sourcing" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/event-sourcing into .github/skills/event-sourcing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "event-sourcing", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add citypaul/.dotfiles --skill event-sourcing -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install citypaul/.dotfiles event-sourcing --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/citypaul/.dotfiles.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/claude/.claude/skills/event-sourcing .opencode/skills/event-sourcing && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "event-sourcing" agent skill from https://github.com/citypaul/.dotfiles/tree/main/claude/.claude/skills/event-sourcing into .opencode/skills/event-sourcing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "event-sourcing", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
event-sourcing- GitHub stars
- 740
- Token cost
- ~7.8k tokens
- SKILL.md length
- 3,101 words
- Files
- 10
- Skills in repo
- 44
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Event sourcing patterns for functional TypeScript — persist state as an append-only log of past events and rebuild it by folding them.
- Works in 4 steps: Events are the source of truth. They are… → State is a left fold of events. There is… → The stream is the consistency boundary.… → …
- Implementing a Decider write model
- SKILL.md covers When to Use Event Sourcing, Core Mental Model, The Decider Is the Write Model and The Command Handler Loop, plus 7 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Event Sourcing is an agent skill from citypaul/.dotfiles. Event sourcing patterns for functional TypeScript — persist state as an append-only log of past events and rebuild it by folding them. Use when implementing a Decider write model, an event store, projections and read models, event versioning, or snapshots. Builds on the Decider from domain-driven-design and the ports/adapters from hexagonal-architecture. Do NOT reach for it on CRUD, or when an audit log or the outbox pattern already suffices.
Its SKILL.md is about 7.8k tokens, which your agent loads only when the skill is triggered. The skill folder holds 10 other files (for example `resources/decider-and-rehydration.md`, `resources/event-store.md` and `resources/event-versioning.md`).
It sits in Backend & APIs, covering Event-driven systems and Domain-driven design. It works with TypeScript.
When your agent uses it
- Implementing a Decider write model
- Projections and read models
- Event versioning
Example prompts
- “/event-sourcing”
Workflow steps
4 steps, taken from the first numbered list in SKILL.md.
- Events are the source of truth. They are immutable facts, named in the past tense, that record what happened and why. You never UPDATE or…
- State is a left fold of events. There is no stored "current state". You rebuild it on demand by folding the evolve function over the…
- The stream is the consistency boundary. One aggregate instance maps to exactly one stream (e.g. account-4f3c…). All invariants for that…
- Read models are disposable derivations. Because state is fold(events), any read-optimised view is just a different fold. You can delete a…
What it can do on your machine
Read from SKILL.md and the folder at commit cd4028d. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are typescript).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Event Sourcing loads about 7.8k tokens when it runs. Until then it costs about 115 tokens; SKILL.md has 3,101 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 3,101 words (~7,807 tokens).
“Event sourcing stores every change to application state as an immutable, append-only sequence of past-tense domain events. The current state is never stored directly — it is a left fold of the events: state = events.reduce(evolve, initialState). The event log…”
- name
- event-sourcing
Files
SKILL.md and 9 other files in claude/.claude/skills/event-sourcing of citypaul/.dotfiles.
- SKILL.md
- resources/decider-and-rehydration.md
- resources/event-store.md
- resources/event-versioning.md
- resources/modelling-events.md
- resources/production-concerns.md
- resources/projections-and-read-models.md
- resources/references.md
- resources/testing-event-sourced-systems.md
- resources/when-to-use-event-sourcing.md
Open the folder on GitHubat commit cd4028d
Compare with similar skills
Event Sourcing next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Event Sourcing this skillcitypaul/.dotfiles | 740 | — | ~7.8k | Automated safety check: Pass | Custom licence | |
| Evolutionary Modular Architecturetech-leads-club/agent-skills | 7k | — | ~3.7k | Automated safety check: Pass | CC-BY-4.0 | |
| Dynamic Consistency BoundariesAxonIQ/AxonFramework | 3.6k | — | ~1.9k | Automated safety check: Pass | Apache-2.0 | |
| NestJS Modular Monolith Architecttech-leads-club/agent-skills | 7k | — | ~3.9k | Automated safety check: Pass | CC-BY-4.0 | |
| AWS Serverless Edazxkane/aws-skills | 367 | 4 repos | ~3.2k | Automated safety check: Pass | MIT | |
| Migration PathAxonIQ/AxonFramework | 3.6k | — | ~594 | Automated safety check: Pass | Apache-2.0 |
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Related
Works with
Categories
Questions about Event Sourcing
What does Event Sourcing do?
Event sourcing patterns for functional TypeScript — persist state as an append-only log of past events and rebuild it by folding them. dotfiles. Event sourcing patterns for functional TypeScript — persist state as an append-only log of past events and rebuild it by folding them.
When should I use Event Sourcing?
Event Sourcing fits situations like: implementing a Decider write model; projections and read models; event versioning.
How do I install Event Sourcing in Claude Code?
Run `npx skills add citypaul/.dotfiles --skill event-sourcing -a claude-code`. Or copy the skill folder (claude/.claude/skills/event-sourcing in citypaul/.dotfiles) into .claude/skills/event-sourcing in your project. Claude Code loads it when a task matches its description.
How do I install Event Sourcing in Codex?
Run `npx skills add citypaul/.dotfiles --skill event-sourcing -a codex`. Or copy the skill folder (claude/.claude/skills/event-sourcing in citypaul/.dotfiles) into .agents/skills/event-sourcing in your project. Codex loads it when a task matches its description.
Can I use Event Sourcing in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add citypaul/.dotfiles --skill event-sourcing -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/event-sourcing, .gemini/skills/event-sourcing, .github/skills/event-sourcing and .opencode/skills/event-sourcing in your project.
What does Event Sourcing need to run?
SKILL.md names no scripts, command-line tools or credentials: Event Sourcing is instructions for the agent only.
Does Event Sourcing access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Event Sourcing safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Event Sourcing use?
Event Sourcing has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Event Sourcing use?
About 7.8k tokens (SKILL.md is roughly 31k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Event Sourcing?
Skills that share tags, products or a category with Event Sourcing: Evolutionary Modular Architecture (tech-leads-club/agent-skills, 7k stars), Dynamic Consistency Boundaries (AxonIQ/AxonFramework, 3.6k stars), NestJS Modular Monolith Architect (tech-leads-club/agent-skills, 7k stars) and AWS Serverless Eda (zxkane/aws-skills, 367 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Event Sourcing?
citypaul (a GitHub user) maintains it in citypaul/.dotfiles, which has 740 GitHub stars. The repository holds 44 skills in this directory. The repository was last updated on October 9, 2026.
Source: citypaul/.dotfiles on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.