How Eazip works

Eazip ships two ways to turn a list of files into a ZIP, behind one API.

Two strategies

local (the default) fetches and zips everything inside the browser tab, using @zip.js/zip.js — no server, no upload, nothing to configure. It's bounded by what the tab can hold in memory, and the export stops if the tab closes or reloads mid-run.

cloud hands the same file list to an Eazip Public Session: the API fetches the sources and builds the archive server-side while the SDK polls the session until it's done. Because the session lives on a server, it survives a reload, scales past what a browser can hold, and splits huge exports into multiple zips automatically. See Why Eazip Cloud.

Both strategies return the same shape of result and go through the same startZip/createZip functions — only strategy: 'cloud' and a publicKey change.

ZipJob: one object, either strategy

Whichever strategy runs, startZip() hands back a ZipJob synchronously. It's the one abstraction worth understanding:

• getSnapshot() / subscribe() — an immutable state snapshot and a subscribe function, deliberately shaped for useSyncExternalStore.
• done — a promise that resolves once the zip is ready ('completed' or 'partial') and rejects only on abort or a fatal error. Safe to ignore.
• abort() — cancels local fetching/zipping, or stops polling a cloud job (the server-side job keeps running either way).

createZip() is sugar for startZip(options).done. See createZip, startZip & ZipJob for the full API.

Picking a strategy

Reach for local first — it's the default, needs no account, and covers most exports: a handful to a few hundred files, tens to low hundreds of megabytes. Move to cloud when:

• the export is large enough that holding it all in memory risks the tab,
• files number in the thousands, or
• the export needs to survive a page reload.

@eazip/react makes switching a one-line change: zip.download({ strategy: 'cloud', publicKey, files }). Same <EazipTray />, same task shape — the tray just gains resumable progress and multi-zip output. See Why Eazip Cloud for what changes under the hood.