# `isValidSignature`

Checks if a signature is valid by calling the [`isValidSignature`](https://github.com/safe-global/safe-smart-account/blob/main/contracts/handler/CompatibilityFallbackHandler.sol#L57) method in the `CompatibilityFallbackHandler` contract.

## Usage


<Tabs items={['example.ts', 'setup.ts']}>
  <Tabs.Tab>
    ```typescript
    import { hashSafeMessage } from '@safe-global/protocol-kit'
    import { EIP712TypedData } from '@safe-global/types-kit'
    import { protocolKit } from './setup.ts'

    const rawMessage: string | EIP712TypedData = 'Example message'
    const messageHash = hashSafeMessage(rawMessage)
    const safeMessageHash = await protocolKit.getSafeMessageHash(messageHash)

    const signature = '0x...'

    const isValidSignature = await protocolKit.isValidSignature(
      safeMessageHash,
      signature
    )
    ```
  </Tabs.Tab>
  <Tabs.Tab>
    ```typescript
    import Safe from '@safe-global/protocol-kit'

    export const protocolKit = Safe.init({
      provider,
      signer,
      safeAddress: '0x...'
    })
    ```
  </Tabs.Tab>
</Tabs>


## Parameters

### `safeMessageHash`

- **Type**: `string`

The Safe message hash.

```typescript focus=2
const isValidSignature = await protocolKit.isValidSignature(
  '0x...', 
  '0x...'
)
```

### `signature`

- **Type**: [`SafeSignature[]`](https://github.com/safe-global/safe-core-sdk/blob/main/packages/types-kit/src/types.ts#L46-L52) | `string`

The signature to be validated.

- `SafeSignature[]` to validate multiple Safe signatures.
- `string` to validate one or multiple signatures concatenated.
- `0x` to validate an on-chain message ([`approvedHashes`](https://github.com/safe-global/safe-smart-account/blob/main/contracts/Safe.sol#L69) in the Safe contract).

```typescript focus=3
const isValidSignature = await protocolKit.isValidSignature(
  '0x...', 
  '0x...'
)
```

## Returns

`Promise<boolean>`

The boolean value that indicates if the signature is valid.