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Query Parameter Passthrough

Instead of creating a link per entity, create one opt-in link and append query parameters per use. They reach your app on open and after a deferred install.

Setup​

Create (or update) the link with passthrough enabled:

curl -X POST https://api.ulink.ly/sdk/links \
  -H "x-api-key: $ULINK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "dynamic",
    "slug": "orders",
    "iosFallbackUrl": "https://apps.apple.com/app/your-app/id0000000000",
    "androidFallbackUrl": "https://play.google.com/store/apps/details?id=com.yourapp",
    "fallbackUrl": "https://yourstore.com/orders",
    "allowQueryPassthrough": true
  }'

Use it​

Append parameters in your emails — no API call per order:

https://x.ulink.ly/orders?orderId=123&coupon=SUMMER

Receive it in the app​

The params arrive in the resolved link's parameters, on every path:

// Flutter
ulink.onLink.listen((data) {
  final orderId = data.parameters?['orderId']; // "123"
});
// Android
ulink.onLink.collect { data ->
  val orderId = data.parameters?.jsonObject?.get("orderId")?.jsonPrimitive?.content
}
// iOS
ulink.onLink.sink { data in
  let orderId = data.parameters?["orderId"] as? String
}

Rules & limits​

  • Override: appended params override stored parameters with the same key, and always arrive as strings.
  • Opt-in: only links created with allowQueryPassthrough: true forward params; others ignore appended query strings.
  • Limits: keys [A-Za-z0-9_-]{1,64}, ≤ 25 params, ≤ 1024 chars/value, ≤ 4 KB total; invalid params are dropped. debug is reserved.