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

# SignatureService

> Swift Protocol

**Protocol**

```swift theme={null}
protocol SignatureService : Sendable
```

## Instance Methods

### approveSignature(\_:)

```swift theme={null}
func approveSignature(_ request: SignRequest) async throws(SignatureError)
```

### createSignature(\_:)

```swift theme={null}
func createSignature(_ request: CreateSignatureRequest) async throws(SignatureError) -> any SignatureApiModel
```

### fetchSignature(\_:chainType:)

```swift theme={null}
func fetchSignature(_ signatureId: String, chainType: ChainType) async throws(SignatureError) -> any SignatureApiModel
```