A minimal ObjC shim (no .xcodeproj) that links any native_sdk.addMobileLib static library and shows its canvas scene on the iOS simulator. Presentation: a CADisplayLink pumps native_sdk_app_frame, and each frame whose canvas revision changed is rendered over the ABI (native_sdk_app_render_pixels, CPU reference renderer, RGBA8), swizzled to BGRA, uploaded with MTLTexture replaceRegion, and blit-copied to the CAMetalLayer drawable — mirroring the macOS raster path in src/platform/macos/appkit_host.m. Input: UITouch sequences forward through the ABI touch/scroll exports (tap presses widgets, over-slop pans scroll through the existing scroll reconciliation), the system keyboard shows/hides off native_sdk_app_text_input_state (textbox focus = first responder), and UITextInput marked text maps onto the native_sdk_app_ime composition path desktop hosts use. Layout: the shim reports the view's safe-area insets through native_sdk_app_viewport and the runtime insets widget layout by them (the canvas still paints edge to edge), so content stays clear of the Dynamic Island / home indicator and relayouts on rotation. Text metrics: a CoreText measure callback registered via native_sdk_app_set_text_measure gives layout real typographic widths (glyph rendering stays the reference renderer's shapes); launch with --estimator-text-metrics to keep the deterministic estimator.

Run

# mobile-canvas on an "iPhone 15" simulator, screenshot + non-blank check
./run.sh

# ui-inbox through the same shim
./run.sh --example-dir ../../ui-inbox --build-arg -Dmobile=true

# options
./run.sh --device "iPhone 15 Pro"   # pick a simulator
./run.sh --build-only               # stop after the .app bundle
./run.sh --shutdown                 # shut the simulator down afterwards

The script cross-compiles the example's embed library (zig build lib -Dtarget=aarch64-ios-simulator), compiles main.m with the simulator SDK, assembles build/<name>/<name>.app, installs + launches it, and fails unless a screenshot samples as non-blank.

Verify input (hardware-true)

# ui-inbox: injected tap grows the list, textbox focus raises the system
# keyboard, typed text lands in the model, drag-scroll moves the offset
./verify_input.sh
./verify_input.sh --device "iPhone 15 Pro" --shutdown

verify_input.sh launches the app with NATIVE_SDK_AUTOMATION=1 (the shim points the runtime's automation snapshots into the app's data container via native_sdk_app_set_automation_dir), compiles InputUITests.m into an XCUITest bundle hosted by the stock XCTRunner.app (generated .xctestrun, xcodebuild test-without-building — still no .xcodeproj), injects real system touch/keyboard events, and asserts model state between steps against snapshot.txt.

Verify layout (safe areas, rotation, scale)

# ui-inbox: widgets lie inside the portrait safe areas, a real rotation
# (XCUITest, no simctl rotate exists) relayouts against the landscape
# insets, and the screenshot pixel/point ratio equals the device scale
./verify_layout.sh
./verify_layout.sh --device "iPhone 15 Pro" --shutdown

Files

main.m — UIWindow + CAMetalLayer view + display link + blit presenter + touch forwarding + UIKeyInput/UITextInput keyboard and IME bridge + CoreText measure callback.
native_sdk_app.h — the ABI subset the shim drives (layouts mirror src/embed/types.zig).
Info.plist.in — bundle plist template (__APP_NAME__/__BUNDLE_ID__ substituted by run.sh).
run.sh — build, bundle, install, launch, screenshot, verify.
InputUITests.m / verify_input.sh — real input injection + snapshot-asserted M3 verification.
verify_layout.sh — snapshot-asserted M4 verification (safe-area insets, rotation relayout, device scale).