# PullSource

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

Defined in: [packages/synapse-sdk/src/types.ts:591](https://github.com/FilOzone/synapse-sdk/blob/814a91db8292f1d8fff6df33f7d00bf7e2a5a52a/packages/synapse-sdk/src/types.ts#L591)

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