WalletConnect Pay via WalletKit - Swift

Integrate WalletConnect Pay through WalletKit for a unified payment experience in your iOS wallet.

This documentation covers integrating WalletConnect Pay through WalletKit. This approach provides a unified API where Pay is automatically configured when you configure WalletKit, simplifying the integration for wallet developers.

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Requirements

• iOS 13.0+
• Swift 5.7+
• Xcode 14.0+
• WalletKit (ReownWalletKit)

Pre-Requisites

In order to use your WalletConnect Pay, you need to obtain an App ID for your project from the WalletConnect Dashboard.

How to obtain an App ID

1. Navigate to the WalletConnect Dashboard.
2. Select the project that is associated with your wallet (as in, the projectId that is being used for your wallet’s WalletConnect integration).

3. Click on the “Get Started” button to get an App ID associated with your project.
4. The Dashboard will now show the App ID associated with your project.
5. Click on the three dots on the right of the App ID and select “Copy App ID”. You will be using this for your wallet’s WalletConnect Pay integration.

Installation

Swift Package Manager

Add ReownWalletKit to your Package.swift:

dependencies: [
    .package(url: "https://github.com/reown-com/reown-swift", from: "1.0.0")
]

Then add ReownWalletKit to your target dependencies:

.target(
    name: "YourApp",
    dependencies: ["ReownWalletKit"]
)

WalletConnectPay is automatically included as a dependency of WalletKit.

Check the GitHub releases for the latest version.

Configuration

When using WalletKit, Pay is automatically configured using your project’s Networking.projectId. No separate configuration is needed.

import ReownWalletKit

func application(_ application: UIApplication, didFinishLaunchingWithOptions...) {
    // Configure WalletKit - Pay is automatically configured
    WalletKit.configure(
        metadata: AppMetadata(
            name: "My Wallet",
            description: "A crypto wallet",
            url: "https://mywallet.com",
            icons: ["https://mywallet.com/icon.png"]
        ),
        crypto: DefaultCryptoProvider(),
        payLogging: true  // Enable Pay debug logging
    )
}

Payment Link Detection

Use the static isPaymentLink method to detect payment links before processing:

// Static method - can be called before configure()
if WalletKit.isPaymentLink(scannedString) {
    startPaymentFlow(paymentLink: scannedString)
}

// Or via the instance
if WalletKit.instance.Pay.isPaymentLink(scannedString) {
    startPaymentFlow(paymentLink: scannedString)
}

The isPaymentLink utility method detects WalletConnect Pay links by checking for:

• pay. hosts (e.g., pay.walletconnect.com)
• pay= parameter in WalletConnect URIs
• pay_ prefix in bare payment IDs

Payment Flow

The payment flow consists of five main steps:

Detect Payment Link -> Get Options -> Get Actions -> Sign Actions -> Confirm Payment

1. Get Payment Options

   When a user scans a payment QR code or opens a payment link, fetch available payment options:

   // 1. Get payment options
   let options = try await WalletKit.instance.Pay.getPaymentOptions(
       paymentLink: paymentLink,
       accounts: ["eip155:1:\(address)", "eip155:137:\(address)"]
   )
   
   // Display merchant info
   if let info = options.info {
       print("Merchant: \(info.merchant.name)")
       print("Amount: \(info.amount.display.assetSymbol) \(info.amount.value)")
   }
   
   // Show available payment options to user
   for option in options.options {
       print("Pay with \(option.amount.display.assetSymbol) on \(option.amount.display.networkName ?? "Unknown")")
   }
   
   // Check which options require data collection
   for option in options.options {
       if option.collectData != nil {
           print("Option \(option.id) requires info capture")
       }
   }
   
2. Get Required Actions

   After the user selects a payment option, get the signing actions:

   // 2. Get required actions for selected option
   let actions = try await WalletKit.instance.Pay.getRequiredPaymentActions(
       paymentId: options.paymentId,
       optionId: selectedOption.id
   )
   
3. Sign Actions

   Each action contains a walletRpc with EIP-712 typed data that needs to be signed:

   // 3. Sign each action and collect signatures
   var signatures: [String] = []
   for action in actions {
       let signature = try await sign(action.walletRpc)
       signatures.append(signature)
   }
   

   Signing Implementation

   private func signTypedData(
       action: Action,
       walletAddress: String,
       signer: YourSignerProtocol
   ) async throws -> String {
       let rpc = action.walletRpc
       
       // Parse params: ["address", "typedDataJson"]
       guard let paramsData = rpc.params.data(using: .utf8),
             let params = try JSONSerialization.jsonObject(with: paramsData) as? [Any],
             params.count >= 2,
             let typedDataJson = params[1] as? String else {
           throw PaymentError.invalidParams
       }
       
       return try await signer.signTypedData(
           data: typedDataJson,
           address: walletAddress
       )
   }
   

   Signatures must be in the same order as the actions array.

4. Collect User Data (If Required)

   If the selected option has collectData set, you must collect user information before confirming:

   WebView-Based Data Collection

   When a payment requires user information (e.g., for Travel Rule compliance), the SDK returns a collectData field on individual payment options. Each option may independently require data collection — some options may require it while others don’t.

   Recommended Flow (Per-Option)

   The recommended approach is to display all payment options upfront, then handle data collection only when the user selects an option that requires it:

   1. Call getPaymentOptions and display all available options to the user
   2. Show a visual indicator (e.g., “Info required” badge) on options where option.collectData is present
   3. When the user selects an option, check selectedOption.collectData
   4. If present, open selectedOption.collectData.url in a WebView within your wallet
   5. Optionally append a prefill=<base64-json> query parameter with known user data (e.g., name, date of birth, address). Use proper URL building to handle existing query parameters.
   6. Listen for JS bridge messages: IC_COMPLETE (success) or IC_ERROR (failure)
   7. On IC_COMPLETE, proceed to confirmPayment() without passing collectedData — the WebView submits data directly to the backend

   Decision Matrix

   Response collectData	option.collectData	Behavior
   present	present	Option requires IC — use option.collectData.url
   present	null	Option does NOT require IC (others might) — skip IC for this option
   null	null	No IC needed for any option

   The collectData also includes a schema field — a JSON schema string describing the required fields. The required list in this schema tells you which fields the form expects. Wallets can use these field names as keys when building the prefill JSON object. For example, if the schema’s required array contains ["fullName", "dob", "pobAddress"], you can prefill with {"fullName": "...", "dob": "...", "pobAddress": "..."}.

   The top-level collectData on the payment options response is still available for backward compatibility. However, the per-option collectData is the recommended approach as it provides more granular control over the flow.

   When using the WebView approach, do not pass collectedData to confirmPayment(). The WebView handles data submission directly.

   // Check per-option data collection requirement after user selects an option
   if let collectData = selectedOption.collectData, let url = collectData.url {
       // Use the "required" list from collectData.schema to determine which fields to prefill
       let prefillData: [String: String] = [
           "fullName": "John Doe",
           "dob": "1990-01-15",
           "pobAddress": "123 Main St, New York, NY 10001"
       ]
       let jsonData = try JSONSerialization.data(withJSONObject: prefillData)
       let prefillBase64 = jsonData.base64EncodedString()
       var components = URLComponents(string: url)!
       var queryItems = components.queryItems ?? []
       queryItems.append(URLQueryItem(name: "prefill", value: prefillBase64))
       components.queryItems = queryItems
       let webViewUrl = components.string!
   
       // Show WebView for this specific option and wait for IC_COMPLETE message
       showWebView(url: webViewUrl)
   }
   

   WebView Message Types

   The WebView communicates with your wallet through JavaScript bridge messages. The message payload is a JSON string with the following structure:

   Message Type	Payload	Description
   IC_COMPLETE	{ "type": "IC_COMPLETE", "success": true }	User completed the form successfully. Proceed to payment confirmation.
   IC_ERROR	{ "type": "IC_ERROR", "error": "..." }	An error occurred. Display the error message and allow the user to retry.

   Platform-Specific Bridge Names

   Platform	Bridge Name	Handler
   Kotlin (Android)	AndroidWallet	@JavascriptInterface onDataCollectionComplete(json: String)
   Swift (iOS)	payDataCollectionComplete	WKScriptMessageHandler.didReceive(message:)
   Flutter	ReactNativeWebView (injected via JS bridge)	JavaScriptChannel.onMessageReceived
   React Native	ReactNativeWebView (native)	WebView.onMessage prop

5. Confirm Payment

   Submit the signatures and collected data to complete the payment:

   // 4. Confirm payment
   let result = try await WalletKit.instance.Pay.confirmPayment(
       paymentId: options.paymentId,
       optionId: selectedOption.id,
       signatures: signatures,
       collectedData: collectedData
   )
   
   switch result.status {
   case .succeeded:
       print("Payment successful!")
   case .processing:
       print("Payment is being processed...")
   case .failed:
       print("Payment failed")
   case .expired:
       print("Payment expired")
   case .requiresAction:
       print("Additional action required")
   }
   

WebView Implementation

When a selected option has collectData.url present, display the URL in a WKWebView. The WebView handles form rendering, validation, and T&C acceptance.

import WebKit
import SwiftUI

struct PayDataCollectionWebView: UIViewRepresentable {
    let url: URL
    let onComplete: () -> Void
    let onError: (String) -> Void

    func makeCoordinator() -> Coordinator {
        Coordinator(onComplete: onComplete, onError: onError)
    }

    func makeUIView(context: Context) -> WKWebView {
        let config = WKWebViewConfiguration()
        config.userContentController.add(
            context.coordinator,
            name: "payDataCollectionComplete"
        )

        let webView = WKWebView(frame: .zero, configuration: config)
        webView.navigationDelegate = context.coordinator
        webView.load(URLRequest(url: url))
        return webView
    }

    func updateUIView(_ uiView: WKWebView, context: Context) {}

    class Coordinator: NSObject, WKScriptMessageHandler, WKNavigationDelegate {
        let onComplete: () -> Void
        let onError: (String) -> Void

        init(onComplete: @escaping () -> Void, onError: @escaping (String) -> Void) {
            self.onComplete = onComplete
            self.onError = onError
        }

        func userContentController(
            _ userContentController: WKUserContentController,
            didReceive message: WKScriptMessage
        ) {
            guard let body = message.body as? String,
                  let data = body.data(using: .utf8),
                  let json = try? JSONSerialization.jsonObject(with: data) as? [String: Any],
                  let type = json["type"] as? String else { return }

            DispatchQueue.main.async {
                switch type {
                case "IC_COMPLETE":
                    self.onComplete()
                case "IC_ERROR":
                    let error = json["error"] as? String ?? "Unknown error"
                    self.onError(error)
                default:
                    break
                }
            }
        }

        func webView(
            _ webView: WKWebView,
            decidePolicyFor navigationAction: WKNavigationAction,
            decisionHandler: @escaping (WKNavigationActionPolicy) -> Void
        ) {
            guard let url = navigationAction.request.url else {
                decisionHandler(.allow)
                return
            }
            if let host = url.host, !host.contains("pay.walletconnect.com") {
                UIApplication.shared.open(url)
                decisionHandler(.cancel)
                return
            }
            decisionHandler(.allow)
        }
    }
}

Complete Example

Here’s a complete implementation using WalletKit:

import ReownWalletKit

class PaymentManager {
    
    func processPayment(
        paymentLink: String,
        walletAddress: String,
        signer: YourSignerProtocol
    ) async throws {
        
        // 1. Get payment options
        let accounts = [
            "eip155:1:\(walletAddress)",
            "eip155:137:\(walletAddress)",
            "eip155:8453:\(walletAddress)"
        ]
        
        let optionsResponse = try await WalletKit.instance.Pay.getPaymentOptions(
            paymentLink: paymentLink,
            accounts: accounts
        )
        
        guard !optionsResponse.options.isEmpty else {
            throw PaymentError.noOptionsAvailable
        }
        
        // 2. Let user select an option (simplified - use first option)
        let selectedOption = optionsResponse.options[0]
        
        // 3. Get required actions
        let actions = try await WalletKit.instance.Pay.getRequiredPaymentActions(
            paymentId: optionsResponse.paymentId,
            optionId: selectedOption.id
        )
        
        // 4. Sign all actions
        var signatures: [String] = []
        for action in actions {
            let signature = try await signTypedData(
                action: action,
                walletAddress: walletAddress,
                signer: signer
            )
            signatures.append(signature)
        }
        
        // 5. Collect data via WebView if required for selected option
        if let collectData = selectedOption.collectData, let url = collectData.url {
            try await showDataCollectionWebView(url: url)
        }

        // 6. Confirm payment
        let result = try await WalletKit.instance.Pay.confirmPayment(
            paymentId: optionsResponse.paymentId,
            optionId: selectedOption.id,
            signatures: signatures
        )
        
        guard result.status == .succeeded else {
            throw PaymentError.paymentFailed(result.status)
        }
    }
    
    private func signTypedData(
        action: Action,
        walletAddress: String,
        signer: YourSignerProtocol
    ) async throws -> String {
        let rpc = action.walletRpc
        
        // Parse params: ["address", "typedDataJson"]
        guard let paramsData = rpc.params.data(using: .utf8),
              let params = try JSONSerialization.jsonObject(with: paramsData) as? [Any],
              params.count >= 2,
              let typedDataJson = params[1] as? String else {
            throw PaymentError.invalidParams
        }
        
        return try await signer.signTypedData(
            data: typedDataJson,
            address: walletAddress
        )
    }
}

Deep Link Handling

To handle payment links opened from outside your app:

// In SceneDelegate or AppDelegate
func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
    guard let url = URLContexts.first?.url else { return }
    
    // Use isPaymentLink for reliable detection
    if WalletKit.isPaymentLink(url.absoluteString) {
        startPaymentFlow(paymentLink: url.absoluteString)
    }
}

QR Code Scanning

Payment links can be encoded as QR codes. Use the isPaymentLink utility for detection:

func handleScannedQR(_ content: String) {
    if WalletKit.isPaymentLink(content) {
        // WalletConnect Pay QR code
        startPaymentFlow(paymentLink: content)
    }
}

API Reference

WalletKit Integration

When using WalletKit, Pay methods are accessed via WalletKit.instance.Pay.*.

Static Methods

Method	Description
WalletKit.isPaymentLink(_:)	Check if a string is a payment link (can call before configure())

Instance Methods (WalletKit.instance.Pay)

Method	Description
isPaymentLink(_:)	Check if a string is a payment link
getPaymentOptions(paymentLink:accounts:includePaymentInfo:)	Fetch available payment options
getRequiredPaymentActions(paymentId:optionId:)	Get signing actions for a payment option
confirmPayment(paymentId:optionId:signatures:maxPollMs:)	Confirm and execute the payment

Data Types

PaymentOptionsResponse

struct PaymentOptionsResponse {
    let paymentId: String              // Unique payment identifier
    let info: PaymentInfo?             // Merchant and amount details
    let options: [PaymentOption]       // Available payment methods
    let collectData: CollectDataAction? // Required user data fields (travel rule)
    let resultInfo: PaymentResultInfo? // Transaction result details (present when payment already completed)
}

struct PaymentResultInfo {
    let txId: String                   // Transaction ID
    let optionAmount: PayAmount        // Token amount details
}

PaymentInfo

struct PaymentInfo {
    let status: PaymentStatus          // Current payment status
    let amount: PayAmount              // Requested payment amount
    let expiresAt: Int64               // Expiration timestamp
    let merchant: MerchantInfo         // Merchant details
    let buyer: BuyerInfo?              // Buyer info if available
}

PaymentOption

struct PaymentOption {
    let id: String                     // Option identifier
    let amount: PayAmount              // Amount in this asset
    let etaS: Int64                    // Estimated time to complete (seconds)
    let actions: [Action]              // Required signing actions
    let collectData: CollectDataAction? // Per-option data collection (nil if not required)
}

PayAmount

struct PayAmount {
    let unit: String                   // Asset unit (e.g., "USDC")
    let value: String                  // Raw value in smallest unit
    let display: AmountDisplay         // Human-readable display info
}

struct AmountDisplay {
    let assetSymbol: String            // Token symbol (e.g., "USDC")
    let assetName: String              // Token name (e.g., "USD Coin")
    let decimals: Int64                // Token decimals
    let iconUrl: String?               // Token icon URL
    let networkName: String?           // Network name (e.g., "Base")
}

Action & WalletRpcAction

struct Action {
    let walletRpc: WalletRpcAction     // RPC call to sign
}

struct WalletRpcAction {
    let chainId: String                // Chain ID (e.g., "eip155:8453")
    let method: String                 // RPC method (eth_signTypedData_v4)
    let params: String                 // JSON-encoded parameters
}

CollectDataAction

struct CollectDataAction {
    let url: String                    // WebView URL for data collection
    let schema: String?                // JSON schema describing required fields
}

ConfirmPaymentResultResponse

struct ConfirmPaymentResultResponse {
    let status: PaymentStatus          // Final payment status
    let isFinal: Bool                  // Whether status is final
    let pollInMs: Int64?               // Suggested poll interval
}

PaymentStatus

enum PaymentStatus {
    case requiresAction                // Additional action needed
    case processing                    // Payment in progress
    case succeeded                     // Payment completed
    case failed                        // Payment failed
    case expired                       // Payment expired
}

Error Handling

The SDK throws specific error types for different failure scenarios:

GetPaymentOptionsError

Error	Description
.paymentNotFound	Payment ID doesn’t exist
.paymentExpired	Payment has expired
.invalidRequest	Invalid request parameters
.invalidAccount	Invalid account format
.complianceFailed	Compliance check failed
.http	Network error
.internalError	Server error

GetPaymentRequestError

Error	Description
.optionNotFound	Selected option doesn’t exist
.paymentNotFound	Payment ID doesn’t exist
.invalidAccount	Invalid account format
.http	Network error

ConfirmPaymentError

Error	Description
.paymentNotFound	Payment ID doesn’t exist
.paymentExpired	Payment has expired
.invalidOption	Invalid option ID
.invalidSignature	Signature verification failed
.routeExpired	Payment route expired
.http	Network error

Best Practices

1. Use WalletKit Integration: If your wallet already uses WalletKit, prefer the WalletKit.instance.Pay.* access pattern for automatic configuration

2. Use isPaymentLink() for Detection: Use the utility method instead of manual URL parsing for reliable payment link detection

3. Account Format: Always use CAIP-10 format for accounts: eip155:{chainId}:{address}

4. Multiple Chains: Provide accounts for all supported chains to maximize payment options

5. Signature Order: Maintain the same order of signatures as the actions array

6. Error Handling: Always handle errors gracefully and show appropriate user feedback

7. Loading States: Show loading indicators during API calls and signing operations

8. Expiration: Check paymentInfo.expiresAt and warn users if time is running low

9. User Data: Only collect data when collectData is present on the selected payment option and you don’t already have the required user data. If you already have the required data, you can submit this without collecting from the user. You must make sure the user accepts WalletConnect Terms and Conditions and Privacy Policy before submitting user information to WalletConnect.

10. WebView Data Collection: When selectedOption.collectData?.url is present, display the URL in a WKWebView rather than building native forms. The WebView handles form rendering, validation, and T&C acceptance.

11. Per-Option Data Collection: When displaying payment options, check each option’s collectData field. Show a visual indicator (e.g., “Info required” badge) on options that require data collection. Only open the WebView when the user selects an option with collectData present — use the option’s collectData.url which is already scoped to that option’s account.