Backblaze B2 MCP Server

Name: Backblaze B2 MCP Server
Author: backblaze-labs

by backblaze-labsversion 0.2.2i★ –iRuns on your computer

Registry nameio.github.backblaze-labs/b2-mcp

Install

Overview

Description from the maker (original English)

Official Backblaze B2 MCP server for buckets, files, keys, Object Lock, and S3 storage.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Other
You need to fill in: B2_APPLICATION_KEY_ID, B2_APPLICATION_KEY, B2_MASTER_KEY_ID, B2_MASTER_KEY

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: B2_APPLICATION_KEY_ID, B2_APPLICATION_KEY, B2_REGION, B2_MASTER_KEY_ID, B2_MASTER_KEY

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "b2": {
      "command": "npx",
      "args": [
        "-y",
        "@backblaze-labs/b2-mcp"
      ],
      "env": {
        "B2_APPLICATION_KEY_ID": "your-value",
        "B2_APPLICATION_KEY": "your-value",
        "B2_REGION": "your-value",
        "B2_MASTER_KEY_ID": "your-value",
        "B2_MASTER_KEY": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add b2 --env B2_APPLICATION_KEY_ID=your-value --env B2_APPLICATION_KEY=your-value --env B2_REGION=your-value --env B2_MASTER_KEY_ID=your-value --env B2_MASTER_KEY=your-value -- npx -y @backblaze-labs/b2-mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "b2": {
      "command": "npx",
      "args": [
        "-y",
        "@backblaze-labs/b2-mcp"
      ],
      "env": {
        "B2_APPLICATION_KEY_ID": "your-value",
        "B2_APPLICATION_KEY": "your-value",
        "B2_REGION": "your-value",
        "B2_MASTER_KEY_ID": "your-value",
        "B2_MASTER_KEY": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "b2": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@backblaze-labs/b2-mcp"
      ],
      "env": {
        "B2_APPLICATION_KEY_ID": "your-value",
        "B2_APPLICATION_KEY": "your-value",
        "B2_REGION": "your-value",
        "B2_MASTER_KEY_ID": "your-value",
        "B2_MASTER_KEY": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

B2_APPLICATION_KEY_ID secret required env
Backblaze B2 application key ID for native B2 and S3-compatible tools.
B2_APPLICATION_KEY secret required env
Backblaze B2 application key secret.
B2_REGION env
Optional fallback S3-compatible region used before authorization.
B2_MASTER_KEY_ID secret env
Optional master key ID for Partner/Groups API tools.
B2_MASTER_KEY secret env
Optional master key secret for Partner/Groups API tools.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account backblaze-labs, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Otheri

More stars than 0% of the other 32706 servers in this category
Published to the registry more recently than 51% of the other 32706 servers in this category
Basic checks equal to or better than 100% of the other 32706 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Backblaze B2 MCP Server safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: B2_APPLICATION_KEY_ID, B2_APPLICATION_KEY, B2_MASTER_KEY_ID, B2_MASTER_KEY

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.2.2) reached the registry 38 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Backblaze B2 MCP Server

A Model Context Protocol server for Backblaze B2 Cloud Storage. It lets any MCP-compatible AI client (Claude, and others) operate B2 through a focused, safe set of tools, currently incubating in Backblaze-Labs.

This is the official Backblaze B2 MCP server — backblaze-labs/b2-mcp, published as @backblaze-labs/b2-mcp on npm and listed in the Official MCP Registry as io.github.backblaze-labs/b2-mcp. Community forks and third-party wrappers are not maintained by Backblaze.

40 tools, assigned by backing category:

Native B2 SDK (`@backblaze-labs/b2-sdk`) (17) — B2 control-plane operations the S3 API has no equivalent for: buckets, application keys, Object Lock, event notifications, and Partner/Groups operations.
AWS S3 SDK (`@aws-sdk/client-s3`) (19) — the S3-compatible data plane: object upload/download/copy/list/delete, multipart, bucket reachability, lifecycle, and presigned URL paths.
Neither SDK (custom MCP code) (4) — repository-owned analytics over B2 reports and bounded live listings: storage growth, egress leaders, largest files, and abandoned uploads.

Destructive actions are gated, durable B2 secrets stay out of the model's context in the default/file/off modes, and registration is capability-aware so a key only ever sees tools it can use. The server also exposes read-only MCP resources: b2://server-config (non-secret, registered even during credential-less discovery), plus capability-gated b2://capabilities and b2://bucket/{bucketName}.

Contents

Quick start
B2 Skills pack
Configuration
Tools
Package API Surface
CLI Reference
Resources
Security & self-hosting
Privacy
Development
Documentation
Backblaze Labs ecosystem

Quick start

Prerequisites: A supported Node.js runtime and a Backblaze B2 application key. A non-master key is all you need. The package engine range is ^22.22.2 || ^24 || ^26; CI runs on Node.js 22.23.1, 24, and 26. One non-master application key covers normal storage work (B2 native, S3, and key management); the Partner/Groups tools additionally need B2_MASTER_KEY_ID / B2_MASTER_KEY.

Option A — npx (Claude Desktop config)

Edit claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\, Linux: ~/.config/Claude/) and add:

"mcpServers": { "backblaze-b2": { "command": "npx", "args": ["-y", "@backblaze-labs/b2-mcp"], "env": { "B2_APPLICATION_KEY_ID": "your-application-key-id", "B2_APPLICATION_KEY": "your-application-key-secret" } } } }

Restart Claude Desktop and the B2 tools appear. If you need an explicit fallback region before authorization, add B2_REGION to the same env block (S3/report tools otherwise derive their region from the authorized B2 account response):

"B2_APPLICATION_KEY_ID": "your-application-key-id", "B2_APPLICATION_KEY": "your-application-key-secret", "B2_REGION": "us-east-005" }

The canonical package name is @backblaze-labs/b2-mcp and the canonical binary is b2-mcp (b2-mcp-server is a transition alias); npx -y @backblaze-labs/b2-mcp runs it directly. See Configuration for the full variable list, and docs/product-specs/clients.md for a source-checkout setup and copy-paste configs for Cursor, VS Code, Cline, Windsurf, Zed, Continue, Goose, Claude.ai, and hosted (Streamable HTTP).

Option B — Claude Desktop extension (MCPB)

Available once a release publishes the b2-mcp.mcpb asset (0.2.1 onward); earlier releases carry no bundle, so use Option A until the asset appears on the releases page.

Prefer no JSON editing? Download `b2-mcp.mcpb` from the latest release, then in Claude Desktop open Settings → Extensions → Advanced settings → Extension Developer → Install Extension… and select the downloaded file. Claude Desktop prompts for your Application Key ID and Application Key (Region and Master keys optional) — no config file to hand-edit. The bundle launches a version-pinned npx -y @backblaze-labs/b2-mcp@ (npm resolves the server on first run) so it always runs the exact published version. A one-click Claude Connectors Directory listing is in progress.

Then just ask:

_"List the buckets this key can access."_ · _"Upload ./data.csv to reports/may-2026.csv."_ · _"Give me a 1-hour download link for backups/latest.tar.gz."_ · _"List files under logs/2026/."_

Why your client may show fewer than 40 tools: registration is capability-aware. With a non-master key and no master key configured, the three Partner/Groups tools that require a master key are not surfaced, so tools/list reports 37; add B2_MASTER_KEY_ID / B2_MASTER_KEY on a Partner-entitled account for the full 40. A read-only key trims the surface further. Credential-free scanners see the full advertised surface, but every tools/call returns missing_credentials until valid B2 credentials are supplied.

Docker

The published image defaults to the HTTP transport and reads configuration only from environment variables (no mutable latest tag — pin the release version):

B2_MCP_VERSION=VERSION # replace with the release version you want

B2_MCP_IMAGE="ghcr.io/backblaze-labs/b2-mcp:${B2_MCP_VERSION}" docker run --rm --name b2-mcp \ --stop-timeout 20 \ -p 127.0.0.1:3000:3000 \ -e B2_HTTP_CREDENTIAL_MODE=server \ -e B2_APPLICATION_KEY_ID=your-application-key-id \ -e B2_APPLICATION_KEY=your-application-key-secret \ -e B2_ALLOWED_HOSTS=localhost,127.0.0.1 \ -e B2_DESTRUCTIVE_POLICY=block \ -e B2_REGISTER_ALL_TOOLS=false \ -e B2_SECRET_SINK=off \ -e B2_ALLOW_INLINE_SECRETS=false \ -e B2_ALLOW_LOCAL_FILES=false \ "$B2_MCP_IMAGE"

For stdio clients inside a container, pass the transport explicitly and keep stdin open:

B2_MCP_VERSION=VERSION # replace with the release version you want

B2_MCP_IMAGE="ghcr.io/backblaze-labs/b2-mcp:${B2_MCP_VERSION}" docker run --rm -i \ --no-healthcheck \ -e B2_APPLICATION_KEY_ID=your-application-key-id \ -e B2_APPLICATION_KEY=your-application-key-secret \ "$B2_MCP_IMAGE" stdio

Deploying to hosted HTTP? See the deployment matrix and provider guides (Docker, Vercel, Cloudflare, AWS, GCP, Azure, Render, Railway, Fly.io) linked from Security & self-hosting, and docs/references/deployment/docker.md for hardened HTTP examples.

B2 Skills pack

This repo bundles a client-side Backblaze B2 skills pack under skills/ (manifest: skills/pack.json) — Markdown playbooks for common workflows (backup/restore, least-privilege keys, Object Lock, lifecycle and cost hygiene, migration, incident response). The MCP server is the action layer; these are the expertise layer. They add no endpoints or permissions — they only sequence existing tools and reinforce the same byte-path and destructive-action guardrails the server enforces.

Optional but recommended for clients that support Markdown skills. Load them by placing each skills/b2-*/ directory under ~/.claude/skills/ (Claude Code), or upload per-skill ZIPs via Settings → Capabilities → Skills (Claude.ai / Claude Desktop). Validate the pack locally:

pnpm run validate:skills

Configuration

Variable	Required	Default	Description
`B2_APPLICATION_KEY_ID`	stdio / HTTP `server`	—	Application key ID (non-master) — the workhorse for native B2 and S3-compatible tools
`B2_APPLICATION_KEY`	stdio / HTTP `server`	—	Application key secret

| B2_MASTER_KEY_ID / B2_MASTER_KEY | — | falls back to a

Only the beginning is shown; read the rest in the repo

Backblaze B2 MCP Server

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Otheri

Common questions

Alternatives

Spec Driven Development

Remote Desktop Commander

Kanal Varna — drains, leaks & plumbing (Varna, BG)

README from the maker

Backblaze B2 MCP Server

Quick start

Option A — npx (Claude Desktop config)

Option B — Claude Desktop extension (MCPB)

Docker

B2 Skills pack

Configuration