Fire the call inside your add-to-cart action handler — after the cart state is updated locally. Don't pass the SKU, price, quantity, or variant; your commerce backend has all of them.
▸Install the Swift (iOS) SDK
// Package.swift
dependencies: [
.package(url: "https://github.com/respectlytics/respectlytics-swift.git", from: "3.0.0")
]
// Or via Xcode → File → Add Packages → paste the URL above.The SDK ships only via Swift Package Manager. CocoaPods and Carthage are not published — fewer integration paths means fewer surfaces to keep audited.
▸Initialize Respectlytics in Swift (iOS)
import Respectlytics
@main
struct MyApp: App {
init() {
Respectlytics.configure(appKey: "<YOUR_APP_KEY>")
}
var body: some Scene { WindowGroup { ContentView() } }
}Call configure once at app launch — typically in your App struct's init. No Info.plist keys are required: the SDK does not call ATTrackingManager and does not request the IDFA, so NSUserTrackingUsageDescription should NOT be added.
▸Track the event in Swift (iOS)
import Respectlytics
func addToCart(productID: String, quantity: Int) {
cart.add(productID: productID, quantity: quantity)
Respectlytics.track("add_to_cart")
// No SKU, no price, no quantity passed.
}
func removeFromCart(productID: String) {
cart.remove(productID: productID)
Respectlytics.track("remove_from_cart")
}If you have a small fixed set of top-level categories worth segmenting, use distinct event names: add_to_cart_apparel, etc.
✦Privacy & implementation notes
Your commerce platform (Shopify, BigCommerce, your own service) is the authoritative cart system — it has SKU, price, quantity, variant, with proper retention and access policies. Mirroring cart contents into product analytics duplicates a system of record and produces drift the moment products are renamed or repriced.
Most product decisions about add-to-cart are about rate changes — "did the new product detail page move our DE iOS add-to-cart rate?". That question doesn't require knowing what specific items got added; it requires knowing the count of add_to_cart events relative to product_detail_view.
Apple rejected approximately 3% of apps in 2024 for incorrectly omitting NSUserTrackingUsageDescription when ATT was required by the SDKs they shipped. Respectlytics doesn't trigger ATT. The corollary is also true: do not add the key on Respectlytics's account — its presence implies you track across apps, even if your code never calls requestTrackingAuthorization.
Internally the Swift SDK uses Swift Concurrency: events are queued in an actor-isolated buffer (RAM-only), flushed on a 30-second timer and on UIApplication.willResignActiveNotification. Force-quit before flush drops queued events — by design. There is no UserDefaults or file backing.
⇋How this compares to other analytics SDKs
| Add-to-cart event | Firebase Analytics | Mixpanel | Respectlytics |
|---|---|---|---|
| SKU / variant ID | Recommended | Recommended | Out of scope |
| Price / currency / quantity | Recommended | Recommended | Rejected by API |
| Cart total at this step | Recommended | Recommended | Out of scope |
| Per-user cart abandonment recovery | Yes | Yes | Out of scope (use cart backend) |
| Add-to-cart *rate* by country / platform | Yes | Yes | Yes |
❓Frequently asked questions
How do we know what's in users' carts without storing items?
Your commerce backend already has authoritative cart state per user. Respectlytics tells you the add-to-cart rate and how it correlates with checkout completion at the session level. Per-user abandoned-cart recovery is a marketing-automation use case, handled by your cart backend's webhooks (Shopify Plus, Klaviyo, etc.).
What about category-level adds (apparel vs electronics)?
If you have a small fixed set of top-level categories (under 8), distinct event names: add_to_cart_apparel, add_to_cart_electronics. Past that, skip the breakdown — your commerce backend has the granular data.
Should we instrument every cart-line edit (quantity changes, removals)?
Removals: yes, distinct event name remove_from_cart — the rate of removals near checkout is a UX signal. Quantity changes: not usually; they don't carry much product signal at the aggregate.
What if the same user adds and removes the same item rapidly?
Both events fire — Respectlytics doesn't dedupe. The rate of remove_from_cart shortly after add_to_cart is itself a UX signal (price reveal, shipping shock, etc.). Bucketing rates over country / platform makes those patterns visible without per-user tracking.