# PullSource

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

Defined in: [packages/synapse-sdk/src/types.ts:545](https://github.com/FilOzone/synapse-sdk/blob/d9d7ff65cc57a0664db3a209a0d25c3a4d4e34f0/packages/synapse-sdk/src/types.ts#L545)

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