Axiom Uikit
Use when bridging UIKit and SwiftUI, modernizing UIKit apps (scene lifecycle, resizability), debugging Auto Layout, Combine, TextKit, PencilKit, or UIKit animations.
- Skill ID
- charleswiltgen/axiom/axiom-uikit
- Publisher
- charleswiltgen
- Repository
- axiom
- Installs
- 0
- Files
- 11
- License
- MIT
- Synced
- Sep 23, 2026
Open any RiverX project, open the Skills panel in the chat, and search for this identifier. The files are fetched from the source repository at install time.
charleswiltgen/axiom/axiom-uikitInstalls these files- SKILL.md
- skills/adaptive-layout.md
- skills/auto-layout-debugging.md
- skills/combine-patterns.md
- skills/pencilkit-paperkit-ref.md
- skills/pencilkit-paperkit.md
- skills/resize-auditor.md
- skills/textkit-ref.md
- skills/uikit-animation-debugging.md
- skills/uikit-bridging.md
- skills/uikit-modernization.md
What this skill tells the agent
UIKit & Bridging
You MUST use this skill for ANY UIKit bridging, Auto Layout, Combine, TextKit, or UIKit animation work.
<!-- AXIOM_AUDITOR_INLINE_BEGIN — auto-maintained by scripts/build-inlined-auditors.ts; do not hand-edit -->
Not on Claude Code? Where this router says "Launchsome-auditoragent", read that auditor's file in this suite and follow it inline — the same procedure, needing only file search and read. Available here:skills/resize-auditor.md. Agents that need Bash — builds, tests, simulators, crash symbolication — stay Claude Code-only; there is no inline equivalent for those.
<!-- AXIOM_AUDITOR_INLINE_END -->
Quick Reference
| Symptom / Task | Reference |
|---|---|
| UIViewRepresentable, UIViewControllerRepresentable | See skills/uikit-bridging.md |
| Embedding SwiftUI in UIKit (UIHostingController) | See skills/uikit-bridging.md |
| Coordinator pattern, updateUIView lifecycle | See skills/uikit-bridging.md |
| Building adaptive UIKit layout: guides, width-conditional constraints, compositional layout, self-sizing cells | See skills/adaptive-layout.md |
| "Unable to simultaneously satisfy constraints" | See skills/auto-layout-debugging.md |
| Constraint conflicts, ambiguous layout | See skills/auto-layout-debugging.md |
| Views not appearing, positioned incorrectly | See skills/auto-layout-debugging.md |
| CAAnimation completion handler not firing | See skills/uikit-animation-debugging.md |
| Spring physics wrong on device, duration mismatch | See skills/uikit-animation-debugging.md |
| Animation jank, CATransaction timing | See skills/uikit-animation-debugging.md |
| Combine publishers, AnyCancellable lifecycle | See skills/combine-patterns.md |
| @Published properties, Combine ↔ async/await | See skills/combine-patterns.md |
| When to use Combine vs async/await | See skills/combine-patterns.md |
UIScene lifecycle required, resizable apps, size classes, tab sidebar OS27 | See skills/uikit-modernization.md |
| iPhone Mirroring compat: indirect input, companion Face ID, portrait trap | See skills/uikit-modernization.md |
| Scene edges: teardown, activation requests, per-scene restoration, external display, activeAppearance | See skills/uikit-modernization.md |
Nav bar title and subtitle: UINavigationItem.subtitle, largeSubtitleView, attributedTitle/attributedSubtitle, subtitle text attributes (iOS 26) | See skills/uikit-modernization.md |
| Automated resize-readiness scan (scene lifecycle, UIScreen.main, fixed-canvas, Mirroring input, iPhone Duo) | Launch resize-auditor agent or /axiom:audit resize |
| iPhone Duo in UIKit: vertical bars, the fold, window requests on the outer display | See axiom-swiftui (skills/iphone-duo.md) — UIKit equivalents sit beside each SwiftUI API |
| TextKit 2 architecture, NSTextLayoutManager | See skills/textkit-ref.md |
| Writing Tools integration (iOS 26) | See skills/textkit-ref.md |
Viewport rendering surfaces, attachment reuse, collapsible text OS27 | See skills/textkit-ref.md |
| SwiftUI TextEditor, TextKit 1 migration | See skills/textkit-ref.md |
Grammar checking (UITextChecker), per-edge text-block borders OS27 | See skills/textkit-ref.md |
| PencilKit canvas, PKToolPicker, drawing persistence | See skills/pencilkit-paperkit.md |
| Apple Pencil Pro (squeeze, barrel roll, hover, haptics) | See skills/pencilkit-paperkit.md |
Handwriting recognition (PKStrokeRecognizer), stroke identity/slicing OS27 | See skills/pencilkit-paperkit-ref.md |
| PaperKit markup canvas (shapes, images, text + drawing) | See skills/pencilkit-paperkit-ref.md |
PaperKit programmatic markup model (subelements, adornments) OS27 | See skills/pencilkit-paperkit-ref.md |
Decision Tree
digraph uikit {
start [label="UIKit task" shape=ellipse];
what [label="What do you need?" shape=diamond];
start -> what;
what -> "skills/uikit-bridging.md" [label="wrap UIKit in SwiftUI\nor SwiftUI in UIKit"];
what -> "skills/adaptive-layout.md" [label="build adaptive layout\n(guides, constraint sets,\ncompositional)"];
what -> "skills/auto-layout-debugging.md" [label="constraint errors,\nlayout issues"];
what -> "skills/uikit-animation-debugging.md" [label="CAAnimation bugs,\nspring physics,\ncompletion handlers"];
what -> "skills/combine-patterns.md" [label="publishers, sinks,\n@Published,\nasync/await bridge"];
what -> "skills/textkit-ref.md" [label="text layout,\nWriting Tools,\nTextKit migration"];
what -> "skills/pencilkit-paperkit.md" [label="drawing canvas,\nApple Pencil,\nPaperKit markup"];
what -> "skills/uikit-modernization.md" [label="scene lifecycle (required 27),\nresizable apps,\nsize classes"];
}- Scene-lifecycle migration, "app won't launch on 27", resizability, size classes, tab sidebar? →
skills/uikit-modernization.md
0b. App misbehaves in iPhone Mirroring (gestures dead, Face ID blocked, layout stuck portrait)? → skills/uikit-modernization.md 0c. iPhone Duo / foldable iPhone (vertical bars, the fold, outer-display window requests)? → axiom-swiftui (skills/iphone-duo.md)
- UIViewRepresentable / UIViewControllerRepresentable / UIHostingController? →
skills/uikit-bridging.md - "Unable to simultaneously satisfy constraints" / layout bugs? →
skills/auto-layout-debugging.md
2b. Building a layout that adapts (layout guides, size-class constraint sets, compositional column math, self-sizing cells)? → skills/adaptive-layout.md
- CAAnimation completion missing / spring physics wrong / animation jank? →
skills/uikit-animation-debugging.md - Combine publishers / AnyCancellable / @Published / Combine ↔ async bridge? →
skills/combine-patterns.md - TextKit 2 / Writing Tools / TextEditor / TextKit 1 migration? →
skills/textkit-ref.md - PencilKit canvas / Apple Pencil / PaperKit markup? →
skills/pencilkit-paperkit.md - Pure SwiftUI view question (no UIKit bridging)? →
/skill axiom-swiftui - Design decisions, HIG, Liquid Glass, SF Symbols, typography? →
/skill axiom-design - Block retain cycles in UIKit callbacks? → See axiom-performance (
skills/objc-block-retain-cycles.md) - Memory leaks from Combine subscriptions? → Start with
skills/combine-patterns.md, then axiom-performance if leak persists
Conflict Resolution
uikit vs swiftui: When working with UI code:
- Use uikit when wrapping UIKit in SwiftUI or vice versa, or debugging UIKit-specific issues (Auto Layout, CAAnimation)
- Use swiftui for pure SwiftUI views, navigation, layout, animations
uikit vs concurrency: When Combine interacts with async/await:
- Use uikit (
skills/combine-patterns.md) for bridging Combine pipelines with async/await - Use concurrency for pure async/await patterns, actors, Sendable
uikit vs performance: When animations or layout cause performance issues:
- Try uikit FIRST — Most animation jank is CATransaction timing or layer state, not a profiling issue
- Only use performance if animation logic is correct but rendering is slow
uikit vs axiom-data: When @Published properties relate to data persistence:
- Use uikit for Combine publisher patterns and @Published lifecycle
- Use axiom-data for SwiftData/Core Data model layer concerns
Anti-Rationalization
| Thought | Reality |
|---|---|
| "I'll just use UIHostingController, it's simple" | Hosting has sizing, lifecycle, and navigation edge cases. skills/uikit-bridging.md covers the gotchas. |
| "Auto Layout error is just a warning, I'll ignore it" | Unsatisfied constraints cause unpredictable layout at runtime. Fix them now. |
| "I know how CAAnimation works" | 90% of CAAnimation bugs are CATransaction timing, not Core Animation. Check skills/uikit-animation-debugging.md. |
More from charleswiltgen
Use this skill in a project
Open any RiverX project, search the Skills panel for charleswiltgen/axiom/axiom-uikit, and install it in one click.
