> For the complete documentation index, see [llms.txt](https://docs.onside.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.onside.io/sdk/reference/errors.md).

# Error Reference

OnsideKit reports failures with small typed enums. Switch over the cases — they are not `LocalizedError`, so `localizedDescription` is generic.

## Common causes

Many cases share a meaning across error types:

<table><thead><tr><th width="260">Case</th><th>Meaning</th></tr></thead><tbody><tr><td><code>loginDiscarded</code></td><td>The user dismissed a required login screen.</td></tr><tr><td><code>cancelled</code></td><td>The operation was cancelled (by the user or <code>stop()</code>).</td></tr><tr><td><code>presentationFailed</code></td><td>OnsideKit couldn't present the purchase UI — no active window scene was available (e.g. the app was backgrounded). The purchase never started; retry once the app is in the foreground.</td></tr><tr><td><code>connectionError</code></td><td>Network failure — usually retryable.</td></tr><tr><td><code>serviceUnavailable</code></td><td>Server returned 5xx — retry later.</td></tr><tr><td><code>appNotRegistered</code></td><td>The app/install isn't recognized by Onside (HTTP 404) — check your app registration/configuration.</td></tr><tr><td><code>invalidProductIdentifier</code></td><td>The products request was rejected (HTTP 422).</td></tr><tr><td><code>internalError</code></td><td>Parsing or other unexpected error.</td></tr><tr><td><code>notLoggedIn</code></td><td>The operation requires an authenticated user.</td></tr><tr><td><code>notSupportedInLocalTesting</code></td><td>Unavailable while running with a <code>.storekit</code> configuration.</td></tr></tbody></table>

## Errors by type

<table><thead><tr><th width="360">Error type</th><th>Cases</th></tr></thead><tbody><tr><td><code>OnsideLoginError</code></td><td><code>loginDiscarded</code></td></tr><tr><td><code>OnsideProductsRequestError</code></td><td><code>cancelled</code>, <code>connectionError</code>, <code>appNotRegistered</code>, <code>invalidProductIdentifier</code>, <code>serviceUnavailable</code>, <code>internalError</code></td></tr><tr><td><code>OnsideSignedInAppsHistoryRequestError</code></td><td><code>notLoggedIn</code>, <code>notSupportedInLocalTesting</code>, <code>cancelled</code>, <code>connectionError</code>, <code>appNotRegistered</code>, <code>serviceUnavailable</code>, <code>internalError</code></td></tr><tr><td><code>OnsidePaymentMethodsManagerError</code></td><td><code>loginDiscarded</code>, <code>notSupportedInLocalTesting</code></td></tr><tr><td><code>OnsidePaymentQueueAddProductError</code></td><td><code>loginDiscarded</code></td></tr><tr><td><code>OnsidePaymentQueueRequestRestoreError</code></td><td><code>loginDiscarded</code></td></tr><tr><td><code>OnsidePaymentTransactionError</code></td><td><code>cancelled</code>, <code>presentationFailed</code></td></tr><tr><td><code>OnsideTransactionsRestoreError</code></td><td><code>cancelled</code>, <code>connectionError</code>, <code>appNotRegistered</code>, <code>serviceUnavailable</code>, <code>internalError</code></td></tr><tr><td><code>OnsideAttributionMetadataError</code></td><td><code>connectionError</code>, <code>appNotRegistered</code>, <code>serviceUnavailable</code>, <code>internalError</code></td></tr></tbody></table>

## Where each is delivered

* `OnsideLoginError` — `Onside.requestLogin(completion:)`
* `OnsideProductsRequestError` — `OnsideProductsRequestDelegate.onsideProductsRequest(_:didFailWithError:)`
* `OnsideSignedInAppsHistoryRequestError` — `Onside.makeSignedInAppsHistoryRequest()` result and its request delegate
* `OnsidePaymentMethodsManagerError` — `Onside.presentPaymentMethodsManager(completion:)`
* `OnsidePaymentQueueAddProductError` — `OnsidePaymentQueue.add(_:completion:)`
* `OnsidePaymentQueueRequestRestoreError` — `OnsidePaymentQueue.restoreCompletedTransactions(completion:)` (pre-flight)
* `OnsidePaymentTransactionError` — `OnsidePaymentTransaction.error` on a `.failed` transaction
* `OnsideTransactionsRestoreError` — `onsidePaymentQueue(_:restoreCompletedTransactionsFailedWithError:)`
* `OnsideAttributionMetadataError` — `Onside.getAttributionMetadata(completion:)`


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