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.
npx skills add garrettw/php-arch-skills --skill domain-modelinggit clone --depth 1 https://github.com/garrettw/php-arch-skillsWrote 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.
[](https://agentmods.dev/skills/garrettw/php-arch-skills/domain-modeling)<a href="https://agentmods.dev/skills/garrettw/php-arch-skills/domain-modeling"><img src="https://agentmods.dev/badge/skills/garrettw/php-arch-skills/domain-modeling/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.
<a href="https://agentmods.dev/skills/garrettw/php-arch-skills/domain-modeling"><img src="https://agentmods.dev/badge/skills/garrettw/php-arch-skills/domain-modeling.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00054 | $0.02963 |
| Opus 5 | $0.00027 | $0.01482 |
| Sonnet 5 | $0.00011 | $0.00593 |
| Haiku 4.5 | $0.00005 | $0.00296 |
Grade A, and why
domain-modeling 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.
How it starts
The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Domain Modeling for PHP Apps
When to Use (and When NOT to)
DDD adds ceremony that must justify its cost. Use DDD when the project has a complex business domain with many rules and will be maintained for years by a team. Skip DDD for prototyping, MVPs, solo-developer projects, or simple CRUD with few business rules.
| Use DDD For | Use Simpler Patterns For |
|---|---|
| Complex business domain with many invariants | Simple CRUD, few business rules |
| Long-lived system (years of maintenance) | Prototype, MVP, throwaway code |
| Team of multiple developers | Solo developer or tiny team (1-2) |
| Multiple entry points (API, CLI, events) | Single entry point, simple API |
| Need to swap infrastructure (DB, broker) | Fixed infrastructure, unlikely to change |
| High test coverage required | Quick scripts, internal tools |
Start simple. Evolve complexity only when needed. Most systems do not need full DDD. For libraries, packages, or SDKs that have no user-facing behavior, plain PSR-4 classes with clear names are usually sufficient. For simple CRUD, lean ORM entities are preferable to rich domain objects.
Note: the choices below (Transaction Script, Table Module, Domain Model) are about how business rules are organized. The Application (or Service) Layer sits above this spectrum — it defines the application's boundary and coordinates whichever domain-logic style you pick. See the application-layer skill for Service Layer definition and the overuse anti-pattern (Controller → Service → Repository → Entity with an anemic domain).
You do not pick one style for the whole codebase
An application does not have to commit to a single domain-modeling style everywhere. Different areas of a system have different complexity, and the right pattern varies by area:
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.
- references/behavioral-structural-patterns.md 5.7 KB
- references/clean-code-foundations.md 6.7 KB
- references/code-taste.md 3.1 KB
- references/decision-flowchart.md 4.8 KB
- references/php-domain-idioms.md 5.0 KB
- references/solid-principles.md 6.4 KB
- references/special-case.md 2.9 KB
- references/table-module.md 6.0 KB
- references/transaction-script.md 4.3 KB
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.
- 9d ago First seen · 121 lines · 54 tokens per session scan A b1ccb9bc5d73
domain-modeling is a skill published in the GitHub repository garrettw/php-arch-skills (12 stars, last pushed 1mo ago), licensed MPL-2.0. It adds 54 tokens to every session and 2,963 once invoked, about $0.0003 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 2026-08-31.
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