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 johnrogers/claude-swift-engineering --skill composable-architecturegit clone --depth 1 https://github.com/johnrogers/claude-swift-engineeringWrote 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/johnrogers/claude-swift-engineering/composable-architecture)<a href="https://agentmods.dev/skills/johnrogers/claude-swift-engineering/composable-architecture"><img src="https://agentmods.dev/badge/skills/johnrogers/claude-swift-engineering/composable-architecture.svg" alt="Measured on agentmods" 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 | $0.00055 | $0.00829 |
| Opus 5 | $0.00028 | $0.00415 |
| Sonnet 5 | $0.00011 | $0.00166 |
| Haiku 4.5 | $0.00006 | $0.00083 |
Grade A, and why
composable-architecture 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 8d 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 — 42 lines — stays where its author put it; the contents beside it link to each section on GitHub.
The Composable Architecture (TCA)
TCA provides architecture for building complex, testable features through composable reducers, centralized state management, and side effect handling. The core principle: predictable state evolution with clear dependencies and testable effects.
Reference Loading Guide
ALWAYS load reference files if there is even a small chance the content may be required. It's better to have the context than to miss a pattern or make a mistake.
| Reference | Load When |
|---|---|
| Reducer Structure | Creating new reducers, setting up @Reducer, State, Action, or @ViewAction |
| Views - Binding | Using @Bindable, two-way bindings, store.send(), or .onAppear/.task |
| Views - Composition | Using ForEach with stores, scoping to child features, or optional children |
| Navigation - Basics | Setting up NavigationStack, path reducers, pushing/popping, or programmatic dismiss |
| Navigation - Advanced | Deep linking, recursive navigation, or combining NavigationStack with sheets |
| Shared State | Using @Shared, .appStorage, .withLock, or sharing state between features |
| Dependencies | Creating @DependencyClient, using @Dependency, or setting up test dependencies |
| Effects | Using .run, .send, .merge, timers, effect cancellation, or async work |
| Presentation | Using @Presents, AlertState, sheets, popovers, or the Destination pattern |
| Testing - Fundamentals | Setting up test suites, makeStore helpers, or understanding Equatable requirements |
| Testing - Patterns | Testing actions, state changes, dependencies, errors, or presentations |
| Testing - Advanced | Using TestClock, keypath matching, exhaustivity = .off, or time-based tests |
| Testing - Utilities | Test data factories, LockIsolated, ConfirmationDialogState testing, or @Shared testing |
| Performance | Optimizing state updates, high-frequency actions, memory, or store scoping |
What ships with it
14 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/dependencies.md 7.4 KB
- references/effects.md 5.4 KB
- references/navigation-advanced.md 4.3 KB
- references/navigation-basics.md 4.2 KB
- references/performance.md 7.6 KB
- references/presentation.md 8.4 KB
- references/reducer-structure.md 6.1 KB
- references/shared-state.md 5.2 KB
- references/testing-advanced.md 8.1 KB
- references/testing-fundamentals.md 4.8 KB
- references/testing-patterns.md 8.9 KB
- references/testing-utilities.md 7.2 KB
- references/views-binding.md 4.1 KB
- references/views-composition.md 4.2 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.
- 8d ago First seen · 42 lines · 55 tokens per session scan A 18f2fd008223
composable-architecture is a skill published in the GitHub repository johnrogers/claude-swift-engineering (228 stars, last pushed 7mo ago), licensed MIT. It adds 55 tokens to every session and 829 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 2026-08-30.
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