# PullSource

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

Defined in: [packages/synapse-sdk/src/types.ts:569](https://github.com/FilOzone/synapse-sdk/blob/a025f71112a5cb0744a4faea8a3f85c0d444a58e/packages/synapse-sdk/src/types.ts#L569)

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