system-architect

A guide for designing software systems and making architecture decisions. It explains choices such as one application versus multiple services, data and API structure, scaling, security, and migration plans.

In plain words
What is it for?
Use it to design new systems, review architecture, plan refactoring or migrations, choose technologies, model data, design APIs, and document technical decisions.
Why use it?
It helps clarify trade-offs before building or changing a system, and helps identify issues such as tightly connected code, bottlenecks, or growing technical debt.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/data-wise/craft/architecture
Any agent
npx skills add Data-Wise/craft --skill architecture
Clone the repo
git clone --depth 1 https://github.com/Data-Wise/craft

Made for: Claude Code, Codex.

Per session 61 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 397 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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.

ModelPer sessionOnce invoked
Fable 5 $0.00061 $0.00397
Opus 5 $0.00030 $0.00198
Sonnet 5 $0.00012 $0.00079
Haiku 4.5 $0.00006 $0.00040

Measured 2d ago against content hash 1a4e758491e6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

system-architect 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 2d 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.

skills/architecture/SKILL.md · 79 lines

What it actually says

System Architect Skill

Expert in software architecture, system design, and technical decision-making.

When to Use

Use this skill when:

  • Designing new systems or features
  • Making architectural decisions
  • Reviewing architecture changes
  • Planning refactoring or migrations
  • Evaluating technical trade-offs

Capabilities

Architecture Patterns

  • Microservices vs monolith decisions
  • Event-driven architecture
  • Domain-driven design (DDD)
  • Clean/hexagonal architecture
  • CQRS and event sourcing

System Design

  • Scalability planning
  • Performance optimization
  • Security architecture
  • Data modeling
  • API design

Technical Leadership

  • Technology selection
  • Build vs buy decisions
  • Technical debt management
  • Migration strategies
  • Documentation standards

Pattern Recognition

  • Anti-pattern detection
  • Coupling/cohesion analysis
  • SOLID principle application
  • Design pattern recommendations

Example Prompts

"Design a scalable architecture for a real-time chat application"
"Should we use microservices or stay with our monolith?"
"Review this architecture for potential bottlenecks"
"How do I refactor this tightly coupled code?"
"What's the best pattern for handling async operations here?"

Outputs

  • Architecture diagrams (Mermaid)
  • Design documents
  • Trade-off analyses
  • Implementation recommendations
  • Migration plans

Integration

Works with:

  • /craft:arch:analyze - Codebase analysis
  • /craft:arch:plan - Architecture planning
  • /craft:arch:review - Architecture review
  • /craft:arch:diagram - Diagram generation
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. 2d ago First seen · 79 lines · 61 tokens per session scan A 1a4e758491e6

Subscribe to this mod's changes

system-architect is a skill published in the GitHub repository Data-Wise/craft (4 stars, last pushed 16d ago), licensed MIT. It adds 61 tokens to every session and 397 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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