SiriCardKit: Instructions file for Codex

Agent rules for building Siri cards

You are building an interactive Siri snippet card (iOS 26+ App Intents). This repo contains a working reference implementation in Sources/CardKit/. Follow these rules exactly; each one was paid for with device debugging time. When a rule here conflicts with your prior knowledge, this file wins.

Architecture (non-negotiable)

1. Three kinds of intent, three jobs:
   • The MAIN intent (DailyBriefIntent pattern): runs on the phrase, returns .result(dialog:snippetIntent:).
   • The SNIPPET intent (BriefSnippetIntent pattern): renders the card. Its perform() MUST be a pure read. The system re-runs it on every redraw. Set static var isDiscoverable: Bool { false }.
   • CONTROL intents (SnoozeIntent pattern): do the mutations. A background control returns plain .result() and the system re-runs the snippet intent automatically; never re-present the snippet from a control, and never point a button at the snippet intent itself.
2. The card view holds only plain values passed in by the snippet intent. No stores, no queries, no model calls inside the view.
3. Dialog is split: IntentDialog(full:supporting:). full is spoken, supporting is the one short line the sheet displays. Never let the sheet print a paragraph above a card that repeats it.
4. Execution modes: data-only intents are .background; intents whose point is opening the app are .foreground(.immediate). If the host app has live navigation state, route warm launches through it and use a UserDefaults courier ONLY for cold launch, drained once after first frame.

Rendering (non-negotiable)

1. NEVER use glassEffect, glassOrSolid, or any Liquid Glass API inside a snippet view. The Siri sheet is itself glass; nested glass makes real devices drop the whole card silently. The simulator will NOT show this failure. Use the kit's CardMaterial (plain gradients and strokes) instead. Transparency in the card reveals the system's own glass, which is the correct way to get a glass look; the kit's glass finish (finish: glass) is that way built in: a white frost, the whole foreground flipped to dark ink, zero glass API.
2. Design for the light platter. Siri hosts the card on a milk-colored material. Any region of the card that fades toward transparent must not have text over it. Use CardMaterial.inkStops(): the shaped fade holds ink through all type and reaches zero only under the action wells. If a design needs text low on the card, raise CardMaterial.floor to 0.88. The ink's hue may be tinted (ink:) but never lightened: the kit clamps ink to the dark register so light text always survives, and on the glass finish it flips the foreground to dark ink for the same reason.
3. Only Button(intent:) and Toggle(isOn:intent:) are interactive in a snippet. Button(action:) and gestures render but do nothing.
4. Keep the card under roughly 340 points tall so the actions stay above the sheet's fold. Excerpt long text by whole sentences with BriefStore.cardExcerpt (budget 140 characters); never truncate mid-sentence and never rely on lineLimit alone.
5. Fixed point sizes, not Dynamic Type styles: a snippet is a fixed canvas. Headline near 28 semibold, values 16 mono, labels 11 to 12 mono, body 15. Minimum text size is 11.
6. Composition: one headline wins the glance; metric rows are label, value, unit on shared rails with values right-aligned in monospaced digits; stat columns come as one block of at most three cells and are the only element allowed near the headline's scale; at most one sentence of prose; at most two action wells, always last; the accent color appears exactly once (the state chip wears it when one exists, the eyebrow otherwise, and that is decided by the kit, not configured).