Sign and verify with Swift - Polygon Developer Docs

Signing produces a signature without preparing or submitting a transaction. Signing and verification require an active wallet session.

Sign and verify a message

let message = "Approve login for example.com"

let signature = try await omsWallet.wallet.signMessage(
    network: .polygonAmoy,
    message: message
)

if let walletAddress = omsWallet.wallet.walletAddress {
    let isValid = try await omsWallet.wallet.isValidMessageSignature(
        network: .polygonAmoy,
        walletAddress: walletAddress,
        message: message,
        signature: signature
    )

    print("Valid:", isValid)
}

signMessage returns a hex-encoded signature. Verification returns Bool.

Sign and verify typed data

Represent EIP-712 typed data with public JSONValue cases.

let typedData: JSONValue = .object([
    "domain": .object([
        "name": .string("Example"),
        "version": .string("1"),
        "chainId": .integer(80002)
    ]),
    "types": .object([
        "Message": .array([
            .object([
                "name": .string("contents"),
                "type": .string("string")
            ])
        ])
    ]),
    "primaryType": .string("Message"),
    "message": .object([
        "contents": .string("Approve login for example.com")
    ])
])

let signature = try await omsWallet.wallet.signTypedData(
    network: .polygonAmoy,
    typedData: typedData
)

if let walletAddress = omsWallet.wallet.walletAddress {
    let isValid = try await omsWallet.wallet.isValidTypedDataSignature(
        network: .polygonAmoy,
        walletAddress: walletAddress,
        typedData: typedData,
        signature: signature
    )

    print("Valid:", isValid)
}

Use the same network and exact payload for signing and verification.

Understand verification context

Both verification methods accept an explicit walletAddress, so you can choose the address checked by the service. They still use the active wallet ID as OMS verification context. The Swift SDK does not expose these methods as unauthenticated verification for arbitrary wallets. If no wallet is active, signing and verification throw a session error. Indexer reads are different: they accept any address without an active wallet session.

​Sign and verify a message

​Sign and verify typed data

​Understand verification context

Sign and verify a message

Sign and verify typed data

Understand verification context