# PullSource

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

Defined in: [packages/synapse-sdk/src/types.ts:611](https://github.com/FilOzone/synapse-sdk/blob/61516150b9c5ae7a7abab1af5db8b22b5d0f5a46/packages/synapse-sdk/src/types.ts#L611)

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