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 agentmods add skills/phase-rs/phase/add-frontend-componentnpx skills add phase-rs/phase --skill add-frontend-componentgit clone --depth 1 https://github.com/phase-rs/phaseWhat 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 | $0.00047 | $0.05552 |
| Opus 5 | $0.00023 | $0.02776 |
| Sonnet 5 | $0.00009 | $0.01110 |
| Haiku 4.5 | $0.00005 | $0.00555 |
Grade A, and why
add-frontend-component 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 3d 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 — 392 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Adding a Frontend Component
Hard rules — all frontend work must respect these (see CLAUDE.md § Design Principles):
- The frontend is a display layer, not a logic layer. It renders engine-provided state and dispatches user actions — nothing more. It must never compute, derive, filter, or re-interpret game data. If a component needs a value the engine doesn't expose, the fix is to add it to the engine's output — not to calculate it client-side. Any "smart" frontend code is a bug.
- CR-correctness is non-negotiable. The frontend must never contradict the Comprehensive Rules. If it displays information (legal targets, valid choices, game state), that information must come directly from the engine, which is the CR-validated source of truth. Never approximate engine logic in TypeScript.
- Build reusable component patterns. New overlays and modals should follow existing patterns (CardChoiceModal, ModeChoiceModal). Extract shared behavior into composable components rather than duplicating across one-off implementations.
- All frontend-authored text is internationalized. Every user-facing string the frontend authors (titles, labels, buttons, tooltips, placeholders, log templates, status messages) MUST go through
t()viareact-i18next— never a hardcoded literal in JSX. The boundary rule: a string getst()if and only if the frontend authored it. Engine/card-database pass-through (card names, Oracle text, interpolated enum strings like phase/mana/counter type) stays raw — it is localized by a separate MTGJSON content pipeline, nott(). Seeclient/src/i18n/README.md(the authority) before adding any string.
The React/TypeScript frontend communicates with the Rust engine through a transport-agnostic adapter layer. Game state flows from engine → adapter → Zustand stores → React components. Player actions flow in reverse via dispatch(). This skill covers wiring new UI components into this pipeline.
Before you start: Trace how ScryChoice works end-to-end. The current path is: WaitingFor::ScryChoice in Rust → TypeScript type in adapter/types.ts → GamePage.tsx renders CardChoiceModal → CardChoiceModal routes to ScryModal → dispatch({ type: "SelectCards", data: { cards } }).
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.
- 3d ago First seen · 392 lines · 47 tokens per session scan A e809cb9d00ae
add-frontend-component is a skill published in the GitHub repository phase-rs/phase (259 stars, last pushed 3d ago), licensed Apache-2.0. It adds 47 tokens to every session and 5,552 once invoked, about $0.0002 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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