> ## Documentation Index
> Fetch the complete documentation index at: https://docs.polygon.technology/llms.txt
> Use this file to discover all available pages before exploring further.

# Sign and verify with Swift

> Sign messages and typed data, then verify signatures with an active Swift wallet session.

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

## Sign and verify a message

```swift theme={null}
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.

```swift theme={null}
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.