# PullSource

> **PullSource** = `string` \| (`pieceCid`) => `string`

Defined in: [packages/synapse-sdk/src/types.ts:508](https://github.com/FilOzone/synapse-sdk/blob/b11ef4f7e3c201d8bba29973a09628063e6547b1/packages/synapse-sdk/src/types.ts#L508)

Source for pulling pieces from another provider.
Either a base URL string or a function that returns a piece URL for a given PieceCID.