Vercel Blob now supports consistent reads on private storage
By Steven Van ·
Passing useCache: false to get() or presignUrl() forces a private blob read straight from origin, skipping the CDN's up-to-60-second cache window.
Reads from Vercel Blob's private storage are normally served through the CDN cache, so overwriting a blob at an existing pathname can leave readers seeing the old version for up to 60 seconds. A new option now guarantees a read reflects the latest write: pass useCache: false to get() or presignUrl().
Blobs written to a fresh pathname are already read-after-write consistent, since there's no existing cached entry to serve instead. The new option matters when a blob at the same pathname gets overwritten, such as an agent's memory file, a session transcript, or a scheduled JSON report. Consistent reads bypass the CDN, take longer than cached reads, and incur Fast Origin Transfer.
The same behaviour works without the SDK by adding a cache=0 query parameter to a private blob URL. Consistent reads require the @vercel/blob 2.6.1 SDK or later, as described in the announcement.