A software design approach that keeps an application's core rules separate from databases, web interfaces, APIs, and other outside systems. It is also called Ports and Adapters and is related to Onion and Clean Architecture.

Use it to structure applications with technology-independent domain logic, interfaces called ports, and replaceable implementations called adapters.

It reduces the risk that business rules become tied to one database, interface, or external service, making the system easier to test and change.

hexagonal — Skill for Claude Code by Tyler-R-Kendrick/agent-skills

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.

Any agent

npx skills add Tyler-R-Kendrick/agent-skills --skill hexagonal

Clone the repo

git clone --depth 1 https://github.com/Tyler-R-Kendrick/agent-skills

Made for: Claude Code.

Or install agent-skills, the plugin that ships this one along with the rest of its 57 skills.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/tyler-r-kendrick/agent-skills/hexagonal/github.svg)](https://agentmods.dev/skills/tyler-r-kendrick/agent-skills/hexagonal)

Your own site

<a href="https://agentmods.dev/skills/tyler-r-kendrick/agent-skills/hexagonal"><img src="https://agentmods.dev/badge/skills/tyler-r-kendrick/agent-skills/hexagonal/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/tyler-r-kendrick/agent-skills/hexagonal"><img src="https://agentmods.dev/badge/skills/tyler-r-kendrick/agent-skills/hexagonal.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 98 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,291 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00098	$0.03291
Opus 5.5	$0.00039	$0.01316
Sonnet 5.5	$0.00020	$0.00658
Haiku 4.5	$0.00010	$0.00329

Measured 2mo ago against content hash 995e7890b32a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

hexagonal 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 2mo 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/dev/architecture/hexagonal/SKILL.md · 338 lines

How it starts

The opening of the file, as written. The whole thing — 338 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hexagonal Architecture (Ports and Adapters)

Overview

Hexagonal Architecture, introduced by Alistair Cockburn in 2005, organizes an application so that the core domain logic is isolated from external concerns (databases, APIs, UIs, message brokers) through ports (interfaces) and adapters (implementations). The goal is to make the application equally drivable by users, programs, automated tests, or batch scripts -- and equally connected to any external system.

The architecture is also known as Ports and Adapters. It shares the same fundamental principle as Onion Architecture (Jeffrey Palermo, 2008) and Clean Architecture (Robert C. Martin): dependencies point inward; the domain depends on nothing external.

The Hexagonal Diagram

                        Driving Side (Primary)
                     (things that USE the app)

                    REST    CLI    Tests   Events
                     │       │      │       │
                     ▼       ▼      ▼       ▼
               ┌─────────────────────────────────┐
               │        Primary Adapters          │
               │    (implement driving ports)      │
               │                                   │
         ┌─────┤─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─┤─────┐
         │     │        Primary Ports              │     │
         │     │    (interfaces the app exposes)   │     │
         │     │                                   │     │
         │     │     ┌───────────────────┐         │     │
         │     │     │                   │         │     │
         │     │     │   Domain Model    │         │     │
         │     │     │   (Pure Business  │         │     │
         │     │     │    Logic)         │         │     │
         │     │     │                   │         │     │
         │     │     └───────────────────┘         │     │
         │     │                                   │     │
         │     │       Secondary Ports             │     │
         │     │   (interfaces the app needs)      │     │
         └─────┤─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─┤─────┘
               │      Secondary Adapters           │
               │   (implement driven ports)        │
               └─────────────────────────────────┘
                     │       │       │       │
                     ▼       ▼       ▼       ▼
                  Postgres  Redis  Stripe  Kafka

                        Driven Side (Secondary)
                    (things the app USES)

Read the full file on GitHub · 338 lines

Files

What ships with it

13 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.

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.

2mo ago First seen · 338 lines · 98 tokens per session scan A 995e7890b32a

Subscribe to this mod's changes

hexagonal is a skill published in the GitHub repository Tyler-R-Kendrick/agent-skills (13 stars, last pushed 5mo ago), licensed MIT. It adds 98 tokens to every session and 3,291 once invoked, about $0.0004 per session on Opus 5.5. 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.

Backend and APIs

hexagonal next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
hexagonalTyler-R-Kendrick/agent-skills	Skill	13	5mo ago	MIT	A	98	Claude Code
mem0-oss-to-platformmem0ai/mem0	Skill	68k	2d ago	Apache-2.0	A	217	Claude Code, Codex
azure-mgmt-botservice-dotnetmicrosoft/skills	Skill	3.2k	yesterday	MIT	A	78	Claude Code
fastapi-router-pymicrosoft/skills	Skill	3.2k	yesterday	MIT	A	46	Claude Code
dev-runtimelangwatch/langwatch	Skill	5.0k	yesterday	Apache-2.0	A	172	Claude Code
api-designericrisco/rsc-harness	Skill	503	2d ago	MIT	A	105	Claude Code, Codex
migrate-segw-to-raparc-mcp/arc-1	Skill	252	yesterday	MIT	A	106	Claude Code