netlify-blobs

---

name: netlify-blobs description: Store and retrieve unstructured objects, files, and cache-like state on Netlify with the @netlify/blobs module. Use when persisting user file uploads (images/documents), caching computed output from functions or Background Functions, serving downloadable assets, storing JSON blobs keyed by ID, or seeding deploy-specific data. Reach for this for key/value or object storage from Functions, Edge Functions, or Build Plugins — not for per-user, transactional, or relational data (use Netlify DB for that). Triggers include "save an uploaded file", "cache API results", "store generated site map", "key/value store for a function", or "file uploads without a database".

Netlify Blobs

Modern syntax — import from @netlify/blobs and open a store, then call methods on the handle:

import { getStore, getDeployStore, listStores } from "@netlify/blobs";
import type { Context } from "@netlify/functions"; // or "@netlify/edge-functions"

In Functions, Edge Functions, and Build Plugins, siteID, deployID, token (and region for getDeployStore) are injected automatically. Install with npm install @netlify/blobs.

Not a database. For dynamic, per-user, transactional, or relational data, use Netlify DB. Blobs is for objects, files, and cache-like state, optimized for frequent reads and infrequent writes.

Store scope is a footgun — read this first. getStore opens a site-wide store shared across ALL deploy contexts: code on a deploy preview reads, overwrites, and deletes production data. Never run destructive tests or seed throwaway data from a preview against a site-wide store. Use getDeployStore() or a context-specific store name for isolation.

Choosing a store type

• getStore(name) — site-wide, shared across all deploys. Data persists across deploys; previews see production data.
• getDeployStore(name) — deploy-specific, scoped to one deploy. Kept in sync on rollback, cleaned up on deploy deletion. Use for isolation and for anything a failed deploy must not corrupt.
• Build plugins can READ from any of the site's stores, but WRITE only to deploy-specific stores (getDeployStore). File-based uploads also write only to deploy-specific stores.

Core writes and reads

const uploads = getStore("file-uploads");

// set: value is ArrayBuffer | Blob | string
await uploads.set(key, file, { metadata: { country: "Spain" } });

// setJSON: any JSON-serializable value
await uploads.setJSON(key, { hello: "world" });

// get: returns value or null. type: text (default) | json | arrayBuffer | blob | stream
const entry = await uploads.get(key);            // string
const obj = await uploads.get(key, { type: "json" });
if (entry === null) { /* 404 */ }

set/setJSON overwrite an existing key. Both return { modified, etag } (etag omitted when no new entry was generated).

Persisting a user upload (Function)

import { getStore } from "@netlify/blobs";
import type { Context } from "@netlify/functions";
import { v4 as uuid } from "uuid";

export default async (req: Request, context: Context) => {
  const form = await req.formData();
  const file = form.get("file") as File;
  const key = uuid();
  const uploads = getStore("file-uploads");
  await uploads.set(key, file, { metadata: { country: context.geo.country.name } });
  return new Response("Submission saved");
};

Edge functions are identical except import type { Context } from "@netlify/edge-functions";.

Reading (Function)

export default async (req: Request, context: Context) => {
  const { key } = context.params;
  const uploads = getStore("file-uploads");
  const entry = await uploads.get(key);
  if (entry === null) return new Response(`Not found: ${key}`, { status: 404 });
  return new Response(entry);
};

Metadata and conditional reads

// getWithMetadata: data + metadata + etag; supports conditional reads
const { data, etag, metadata } = await uploads.getWithMetadata(key);

// getMetadata: metadata + etag only, without downloading the blob
const meta = await uploads.getMetadata(key); // { etag, metadata } or null

Both return null if the key is absent. Both accept { consistency, etag, type }.

Conditional read: pass a cached etag; if it still matches server-side, data is null (your copy is fresh). Compare the whole ETag value including surrounding quotes and any weakness prefix.

const { data, etag } = await uploads.getWithMetadata("my-key", { etag: cachedETag });
if (etag === cachedETag) {
  // data is null — cached copy still fresh
}

Concurrency: atomic conditional writes

Last write wins — there is no concurrency control. Do NOT build counters, balances, or read-modify-write logic on a blob key, even with onlyIfMatch retries — that is transactional data; use Netlify DB.

set/setJSON accept { onlyIfNew, onlyIfMatch }:

// Create only if key does not exist
const { modified } = await emails.set("jane@netlify.com", "Jane Doe", { onlyIfNew: true });
if (!modified) return new Response("Email already exists", { status: 400 });

// Update only if the ETag still matches
const { modified } = await emails.set("jane@netlify.com", "New Jane", { onlyIfMatch: etag });
if (!modified) return new Response("Cached data is stale", { status: 400 });

Listing

const { blobs } = await uploads.list(); // blobs: [{ etag, key }]

list({ directories, paginate, prefix }). Group keys hierarchically with /:

const { blobs, directories } = await animals.list({ directories: true });
// directories: ["cats", "dogs"]; blobs: top-level keys only

// Drill in — trailing slash REQUIRED (without it "catsuit" also matches)
const res = await animals.list({ directories: true, prefix: "cats/" });

Pagination: list returns all pages by default (pages of up to 1,000 entries). Set paginate: true for an AsyncIterator:

for await (const page of store.list({ paginate: true })) {
  console.log(page.blobs);
}

listStores({ paginate }) returns { stores: string[] } — does not include deploy-specific stores (pages of up to 1,000).

Deleting

await uploads.delete(key);                        // resolves undefined
const { deletedBlobs } = await uploads.deleteAll(); // deletes every object = deletes the store

Expiration (no server-side TTL)

Blobs never expire on their own. Store an expiration timestamp in metadata, check it on read, and delete when past:

await uploads.set(key, body, { metadata: { expiration: new Date("2025-01-01").getTime() } });
const entry = await uploads.getWithMetadata(key);
const { expiration } = entry.metadata;
if (expiration && expiration < Date.now()) await uploads.delete(key);

Consistency

Default is eventual consistency: writes are globally available immediately, but updates/deletions propagate to all edge locations within 60 seconds. Opt into strong consistency per store or per read:

const store = getStore({ name: "animals", consistency: "strong" }); // whole store
await store.get("dog", { consistency: "strong" });                  // single read

Netlify CLI always uses strong consistency.

Regions

region takes an AWS region code (not the functions airport code). Supported (any other value throws InvalidBlobsRegionError before the request): ap-southeast-1, ap-southeast-2, eu-central-1, us-east-1, us-east-2.

• Deploy-specific stores default to your functions region (auto-injected).
• Site-wide stores default to us-east-2 and do NOT follow your functions region.

Footgun — site-wide region is per-call: if you need a site-wide store in a specific region, pass region on every getStore call for that store (reads, writes, deletes). A call that omits it uses us-east-2 and silently sees no data — no error or warning.

Footgun — changing a region does not move data: the store appears empty in the new region while data remains in the old. To migrate, copy each entry to a store opened in the new region, then delete from the old.

const uploads = getDeployStore({ name: "file-uploads", region: "ap-southeast-2" });
const profiles = getStore({ name: "user-profiles", region: "eu-central-1" });

File-based uploads (no build plugin)

Place files under .netlify/blobs/deploy in the base directory; Netlify uploads them (preserving directory structure) to deploy-specific stores. Attach metadata with a sibling JSON file named $<filename>.json (must be valid JSON or the deploy fails).

.netlify/blobs/deploy/
├─ dogs/good-boy.jpg
├─ dogs/$good-boy.jpg.json   # metadata for good-boy.jpg
├─ cat.jpg
└─ mouse.jpg

Caution: Netlify empties .netlify/blobs/deploy before each build. Files committed to your repo are NOT uploaded — create blob files during the build (build command or build plugin).

Access control (default to private)

Blobs have no built-in access control — the serving function is the gate. Blobs are only reachable through your own site's code, encrypted at rest and in transit. When in doubt, default to private: gate reads behind an authenticated function rather than exposing blobs publicly. Do not serve arbitrary user-supplied keys for sensitive data; scope keys with something callers cannot tamper with. Blobs is not part of Netlify's HIPAA-compliant offering.

Constraints

• Store names: no / or :, max 64 bytes.
• Keys: non-empty, cannot start with /, max 600 bytes, any Unicode (some chars >1 byte).
• Object size max 5 GB; metadata max 2 KB.
• Functions written in Go cannot access Netlify Blobs.
• Fetch API required (Node.js 18+); otherwise pass a custom fetch: getStore({ fetch, name: "file-uploads" }).
• Local dev (Netlify Dev) uses a sandboxed local store: no file-based uploads, cannot read production data.
• File-based uploads require continuous deployment or CLI deploys.

When an operation fails

Surface the error and read the function logs. Do not invent REST endpoints or side-channel APIs to retry.

CLI and UI

netlify blobs:list/get/set/delete exist for inspection — see the CLI command reference. Browse and download in the UI under Data & Storage > Blobs.

Module version migration

If you wrote to site-wide stores with @netlify/blobs 6.5.0 or earlier and upgrade, those stores become inaccessible due to a namespacing change. Migrate with the latest CLI, then use module 7.0.0+:

netlify recipes blobs-migrate YOUR_STORE_NAME

Reference

Full API and background: Netlify Blobs docs and the data & storage overview.

<!-- system: agent-context/blobs/system.md — human-owned, merged by ctx-gen; edit system.md, not this section -->

Netlify house rules (blobs)

These are org conventions, not docs facts — merged into the rendered skill by ctx-gen and never generated. Owned by the skills maintainer.

1. Blobs is not a database. For dynamic, per-user, or transactional data, use Netlify DB — Blobs is for objects, files, and cache-like state.
2. When a store operation fails, surface the error and read the function logs — do not invent REST endpoints or side-channel APIs to retry.
3. netlify blobs:list/get/set/delete exist for inspection; the CLI reference is their source of truth — link, don't restate.
4. Blobs have no built-in access control — the serving function is the gate. When in doubt, default to private: gate reads behind an authenticated function rather than exposing blobs publicly.
5. Site-scoped stores are shared across ALL deploy contexts — code on a deploy preview reads, overwrites, and deletes production data. Never run destructive tests or seed throwaway data from previews; use getDeployStore() or a context-specific store name for isolation.
6. Don't build counters, balances, or read-modify-write logic on a blob key — even with onlyIfMatch retries. That's transactional data; use Netlify DB.
7. Build plugins: state BOTH halves — they can read from any of the site's stores, but write only to deploy-specific stores (getDeployStore).