# Type Alias: SiwbbMessage

> **SiwbbMessage** = `string`

Defined in: [packages/bitbadgesjs-sdk/src/api-indexer/docs-types/interfaces.ts:74](https://github.com/BitBadges/bitbadgesjs/blob/master/packages/bitbadgesjs-sdk/src/api-indexer/docs-types/interfaces.ts#L74)

SiwbbMessage is the sign-in challenge strint to be signed by the user. It extends EIP 4361 Sign-In with Ethereum
and adds additional fields for cross-chain compatibility and native asset ownership verification.

For example, 'https://bitbadges.io wants you to sign in with your Ethereum address ...'