createFileSystemTransferCheckpointStore

function createFileSystemTransferCheckpointStore(options: FileSystemTransferCheckpointStoreOptions): TransferCheckpointStore;

Defined in: src/transfers/TransferCheckpointStore.ts:308

File-system backed TransferCheckpointStore that survives process restarts, enabling cross-process resume.

Each checkpoint is one JSON file named after a SHA-256 hash of the transfer key. Writes are atomic (<file>.tmp then rename) with mode 0600, so a crash mid-write cannot leave a corrupt checkpoint and other local users cannot read transfer metadata. Corrupt or expired files are deleted on load and treated as absent.

Parameters

Parameter	Type
options	FileSystemTransferCheckpointStoreOptions

Returns

TransferCheckpointStore

Example

import {
  createFileSystemTransferCheckpointStore,
  createTransferClient,
  downloadFile,
} from "@zero-transfer/sdk";

const store = createFileSystemTransferCheckpointStore({
  directory: "./.zt-checkpoints",
});

const client = createTransferClient({
  providers: [createSftpProviderFactory(), createLocalProviderFactory()],
  defaults: { resume: { store } },
});

// Kill the process mid-transfer and run it again: the download resumes
// from the last committed byte instead of restarting.
await downloadFile({ client, source, destination });