Vercel Blob Storage

Alpha

DSAR is currently in alpha. APIs, package surfaces, configuration, and documentation may change as the project evolves.

@dsar/storage-vercel-blob stores DSAR fulfilment artifacts in Vercel's managed blob storage service. Zero infrastructure setup when deploying on Vercel.

Installation

Package manager	Command
npm	`npm install @dsar/storage-vercel-blob`
pnpm	`pnpm add @dsar/storage-vercel-blob`
yarn	`yarn add @dsar/storage-vercel-blob`
bun	`bun add @dsar/storage-vercel-blob`

Setup

import { dsarInstance } from "@dsar/backend";
import { makeVercelBlobStorageAdapter } from "@dsar/storage-vercel-blob";

const runtime = dsarInstance({
	adapters: {
		inbound: "stub",
		notifications: "stub",
		storage: makeVercelBlobStorageAdapter({
			prefix: "artifacts",
			readWriteToken: process.env.BLOB_READ_WRITE_TOKEN,
			retryMaxAttempts: 3,
			timeoutMs: 3000,
		}),
	},
});

Configuration

Option	Default	Description
`readWriteToken`	`process.env.BLOB_READ_WRITE_TOKEN`	Vercel Blob read-write token
`prefix`	`artifacts`	Key prefix for all stored objects
`addRandomSuffix`	`false`	Append random suffix to keys
`allowOverwrite`	`false`	Allow overwriting existing objects
`cacheControlMaxAge`	—	CDN cache-control max age
`timeoutMs`	`10000`	Request timeout in milliseconds
`retryMaxAttempts`	`3`	Retry count for retriable failures

Key Layout

Default deterministic key format:

<prefix>/<requestId>/<manifestId>/<category>/<redaction>/<thirdParty>/<artifactName>

Fallback values:

missing requestId → request-unknown
missing manifestId → manifest-unknown
missing category → uncategorized
missing name/id → artifact.bin

Error and Retry Behaviour

Category	Retriable	Examples
`timeout`	yes	request abort, blob service unavailable
`rate_limit`	yes	blob rate limiting / throttling
`network`	yes	fetch/socket connectivity failures
`auth`	no	invalid token, store suspended/not found
`validation`	no	malformed input/config
`config`	no	adapter setup invalid
`unknown`	no	unmatched provider errors

Caching and Overwrite Notes

Vercel Blob put(...) requires access: "public" and serves content through CDN cache.
Prefer immutable pathnames and keep allowOverwrite disabled unless you explicitly need mutation.
If overwrite is enabled, cached clients may still observe stale content until cache expiry (cacheControlMaxAge).