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 frontal-labs/mcp-server --skill architecture-patternsgit clone --depth 1 https://github.com/frontal-labs/mcp-serverWrote 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/frontal-labs/mcp-server/architecture-patterns)<a href="https://agentmods.dev/skills/frontal-labs/mcp-server/architecture-patterns"><img src="https://agentmods.dev/badge/skills/frontal-labs/mcp-server/architecture-patterns/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/frontal-labs/mcp-server/architecture-patterns"><img src="https://agentmods.dev/badge/skills/frontal-labs/mcp-server/architecture-patterns.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 | $0.00065 | $0.01630 |
| Opus 5.5 | $0.00026 | $0.00652 |
| Sonnet 5.5 | $0.00013 | $0.00326 |
| Haiku 4.5 | $0.00006 | $0.00163 |
Grade A, and why
architecture-patterns 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 yesterday.
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.
This is a copy
100% identical to architecture-patterns — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 165 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Architecture Patterns
Master proven backend architecture patterns including Clean Architecture, Hexagonal Architecture, and Domain-Driven Design to build maintainable, testable, and scalable systems.
Given: a service boundary or module to architect. Produces: layered structure with clear dependency rules, interface definitions, and test boundaries.
When to Use This Skill
- Designing new backend services or microservices from scratch
- Refactoring monolithic applications where business logic is entangled with ORM models or HTTP concerns
- Establishing bounded contexts before splitting a system into services
- Debugging dependency cycles where infrastructure code bleeds into the domain layer
- Creating testable codebases where use-case tests do not require a running database
- Implementing domain-driven design tactical patterns (aggregates, value objects, domain events)
Core Concepts
1. Clean Architecture (Uncle Bob)
Layers (dependency flows inward):
- Entities: Core business models, no framework imports
- Use Cases: Application business rules, orchestrate entities
- Interface Adapters: Controllers, presenters, gateways — translate between use cases and external formats
- Frameworks & Drivers: UI, database, external services — all at the outermost ring
Key Principles:
- Dependencies point inward only; inner layers know nothing about outer layers
- Business logic is independent of frameworks, databases, and delivery mechanisms
- Every layer boundary is crossed via an abstract interface
- Testable without UI, database, or external services
2. Hexagonal Architecture (Ports and Adapters)
Components:
- Domain Core: Business logic lives here, framework-free
- Ports: Abstract interfaces that define how the core interacts with the outside world (driving and driven)
- Adapters: Concrete implementations of ports (PostgreSQL adapter, Stripe adapter, REST adapter)
Benefits:
- Swap implementations without touching the core (e.g., replace PostgreSQL with DynamoDB)
- Use in-memory adapters in tests — no Docker required
- Technology decisions deferred to the edges
What ships with it
2 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.
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.
- yesterday First seen · 165 lines · 65 tokens per session scan A 350caf22b856
architecture-patterns is a skill published in the GitHub repository frontal-labs/mcp-server (1 stars, last pushed yesterday), licensed Apache-2.0. It adds 65 tokens to every session and 1,630 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to architecture-patterns, differing in 0 lines, and is treated as a copy.
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