Claude + Fast.io

Cloud Storage for Claude

Claude is powerful. Your files should be too. Give Claude a content workspace to manage documents, collaborate on code, and share results with your team.

llms.txt • skill.md

Get started with Claude Desktop

Connect Fast.io to Claude Desktop with a custom connector.

First, we'll ensure Claude can upload to Fast.io

Open Claude Desktop and click the user menu in the bottom-left corner. Select Settings.

Claude Desktop user menu with Settings option

Add *.fast.io to allowlist

Go to Capabilities, scroll down to Domain allowlist, paste the domain below, then click Add. This allows Claude to upload files to your workspaces.

*.fast.io

Claude Desktop Capabilities settings with Domain Allowlist

Go to Customize to add the connector

Click Customize in the left sidebar.

Claude Desktop sidebar with Customize option

Go to Connectors

Select Connectors in the menu.

Claude Desktop Customize page showing Connectors section

Add a custom connector

Click the + button at the top of the Connectors list and select Add custom connector from the dropdown.

Claude Desktop Connectors list with Add custom connector dropdown

Enter the connector name

In the dialog, enter the connector name below (or another name if you desire).

fast-io

Add the MCP server URL

Paste the MCP URL below into the Remote MCP server URL field, then click Add.

https://mcp.fast.io/mcp

Add custom connector dialog with MCP URL filled in

Connect to the Fast.io MCP Server

The Fast.io connector is now added. With it selected, click the Connect button in the right pane. If you don't see this button, (you may have previously connected to Fast.io).

Claude Desktop Fast.io connector with tool permissions

Review permissions

You'll be redirected to Fast.io to review the permissions for the Fast.io MCP Agent. Here, you can configure organization and workspace access. Click Continue when ready.

Approve the connection

Confirm the connection by clicking Approve to grant the Fast.io MCP Agent access to your account.

Fast.io approve access confirmation page

Authorization successful

After approval, you'll see a confirmation page. You'll then automatically be redirected back to Claude Desktop.

Fast.io authorization code page with Copy Code button

You're all set

Claude is now connected to your Fast.io account. You can ask Claude for details about your account to confirm the connection.

Claude Desktop showing Fast.io account details

Try these prompts

Copy and paste these into Claude to see Fast.io in action.

List all workspaces in this account

Create a new folder named "Images"

Give me a link to this newly created
                                        folder

Get started with Claude Code

Add the Fast.io MCP server to Claude Code using your terminal.

Add the MCP server

Open your terminal and run the command below. This will add the Fast.io MCP server to Claude Code.

claude mcp add --transport http fast-io
                                    https://mcp.fast.io/mcp

Claude Desktop Fast.io connector permission configuration

Check the MCP server list

Run the command below to confirm fast-io appears in your MCP server list.

claude mcp list

Verify that the MCP server was added

The newly added MCP server, fast-io, should now appear in the list with a Connected status indicator.

Start a new Claude Code session

Open a new Claude Code session by running the command below in your terminal.

claude

Open the Fast.io agent guide

Type /fast-io to open the Fast.io agent guide. This will display common starting points.

/fast-io

Sign in to your Fast.io account

Fast.io will prompt you with common starting points. Type sign in to begin the authentication flow and connect Claude Code to your account.

Choose an authentication method

In the auth method list, choose the Browser login (PKCE) option with up/down arrow keys.

Open the sign-in URL in your browser

Claude Code will generate a sign-in URL. Copy the entire URL and paste it into your browser.

Sign in to Fast.io

Review permissions

Choose the access level for Claude Code. Select Full Access to give Claude complete access to your organizations and workspaces, or configure specific organization and workspace permissions.

Approve the connection

Review the permissions summary and click Approve to authorize Claude Code to access your Fast.io account.

Copy the authorization code

After approving, Fast.io will display an authorization code. Click Copy Code to copy it to your clipboard. You'll paste this back into Claude Code in the next step.

Paste the code into Claude Code

Return to your terminal and paste the authorization code where Claude Code is waiting. This completes the authentication handshake between Claude Code and Fast.io.

Authentication complete

Claude Code confirms you're signed in and your session is active. You can now start using Fast.io tools directly from the terminal.

Explore your Fast.io account

Ask Claude something like "can you see your fast.io account?" to get a summary of your profile, organization, plan details, and remaining credits.

Try these prompts

Copy and paste these into Claude to see Fast.io in action.

List all workspaces in this account

Create a new folder named "Images"

Give me a link to this newly created
                                        folder

Everything your agents need to get work done

Give Claude a secure space to store, analyze, and share files alongside your team.

API

org-create-workspace

Create project-scoped workspaces on demand. Intelligence mode auto-indexes files for RAG.

Files + Folders

workspace-storage-*

CRUD, move, copy, versions, locks, previews for 10+ formats. Chunked uploads up to 1GB.

Import

web-upload

Import files from any URL. OAuth support for Google Drive, OneDrive, Box, Dropbox. No local I/O.

Semantic Search

workspace-search

Find files by meaning, not keywords. "Show me contracts with indemnity clauses" works.

AI Chat (RAG)

ai-chat-create

Ask questions across entire workspaces. Auto-summarization, citations, metadata extraction.

MCP Server

mcp.fast.io

251 tools via Streamable HTTP or SSE. Session state persisted in Durable Objects.

Webhooks

webhook-create

Real-time notifications for file events. Build reactive workflows without polling.

Ownership Transfer

org-transfer-ownership

Build for humans, then hand off. Agent keeps admin access after transfer.

Shares & Content Portals

share-create

Three modes: Send (deliver), Receive (collect), Exchange (collaborate). Password protection, expiration, branding.

Comments & Annotations

comments-*

Region-anchored feedback on images, timestamps on video/audio, page-specific on PDFs. Threaded replies.

$0/mo

Free forever. No credit card required.

50 GB

Cloud Storage

5,000

Monthly Credits

251

MCP Tools

Monthly credits cover storage, bandwidth, and AI operations. Resets every 30 days.

FAQ

What is the Fast.io MCP server?

It's a server that provides Claude with 251 workspace tools. By adding it to your config, Claude can upload files, create share links, and query documents using RAG.

How does authentication work?

The first time Claude uses a Fast.io tool, it opens a browser tab to sign in or create a free account. Your session persists, so there are no API keys to manage manually.

Can I see what Claude uploads?

Yes. Everything Claude stores is accessible at app.fast.io. You can browse, preview, comment on, and download files from any device.

Does this work with Claude Desktop and Claude Code?

Yes. It works with both. For Claude Desktop, you add the MCP config to your settings. For Claude Code, you use the 'claude mcp add' command.

What happens when I hit the credit limit?

You get 5,000 credits per month. When they run out, new uploads and AI queries pause until the next cycle. Existing files and share links remain accessible.

Can Claude share files with people who don't use Claude?

Yes. Share links are regular web URLs. Recipients open them in a browser and get previews, downloads, and commenting features without needing an account.

Fastio CLI

Claude Code users are already in the terminal.

The Fastio CLI gives you the same workspace tools — upload, search, share — as a standalone command. It also includes a built-in MCP server via fastio mcp.


npm install --global @vividengine/fastio-cli

Learn more

Give Claude a professional workspace

Enable 251 tools for Claude in minutes. Built-in shared workspaces, RAG search, and file sharing.

Get Started Setup Guide