iOS SDK

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Installation

Add package LinkSDK in your project’s Package Dependencies or download LinkSDK.xcframework.

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Get Link token

Link token should be obtained from the POST /api/v1/linktoken endpoint. API reference for this request is available here. The request must be performed from the server side because it requires the client’s secret. You will get the response in the following format:

Set up GetFrontLinkSDK with the linkToken

{
  "content": {
    "linkToken": "{linkToken}"
  },
  "status": "ok",
  "message": ""
}

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Launch Link

Create a LinkConfiguration instance with the linkToken and the callbacks:

let configuration = LinkConfiguration(
    linkToken: linkToken,
    settings: LinkSettings?,
    onIntegrationConnected: onIntegrationConnected,
    onTransferFinished: onTransferFinished,
    onEvent: onEvent,
    onExit: onExit)

The callback onIntegrationConnected is called with LinkPayload once an integration has been connected.

let onIntegrationConnected: (LinkPayload)->() = { linkPayload in
    switch linkPayload {
    case .accessToken(let accessTokenPayload):
        print(accessTokenPayload)
    case .delayedAuth(let delayedAuthPayload):
        print(delayedAuthPayload)
    }
}

The callback onTransferFinished callback is called once a crypto transfer has been executed or failed. The parameter is either success(TransferFinishedSuccessPayload) or error(TransferFinishedErrorPayload).

The callback onEvent is called to provide more details on the user’s progress while interacting with the Link. This is a list of possible event types, some of them may have additional parameters:

• loaded
• integrationConnectionError
• integrationSelected
• credentialsEntered
• transferStarted
• transferPreviewed
• transferPreviewError
• transferExecutionError

The callback onExit is called once a user exits the Link flow. It might be used to dismiss the Link view controller in case the app manages its life cycle (see LinkHandler.create())

Callback closures are optional, but either onIntegrationConnected or onTransferFinished must be provided.

Create a LinkHandler instance by calling createHandler() function, or handle an error. The following errors can be returned:

• Invalid linkToken
• Either onIntegrationConnected or onTransferFinished callback must be provided

let result = configuration.createHandler()
switch result {
case .failure(let error):
    print(error)
case .success(let handler):
    handler.present(in: self)
}

In case of success, you can call LinkHandler.present (in viewController) function to let LinkSDK modally present the Link view controller and dismiss it on exit, or get the reference to a view controller by calling LinkHandler.create() if you prefer your app to manage its life cycle.

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Adding URL Schemes to Info.plist

To enable our SDK to interact with specific apps, please add the following URL schemes to your info plist file

• Open your info.plist located in the ‘ios’ directory of your React Native project
• Add the following XML snippet within the <dict></dict> tag.

<key>LSApplicationQueriesSchemes</key>
<array>
    <string>trust</string>
    <string>robinhood</string>
    <string>metamask</string>
    <string>rainbow</string>
    <string>uniswap</string>
    <string>exodus</string>
    <string>robinhood-wallet</string>
    <string>blockchain-wallet</string>
    <string>1inch</string>
    <string>cryptowallet<string>
    <string>okx</string>
    <string>bitkeep</string>
</array>