Get started with Codex Desktop
Connect Fastio to Codex Desktop with a custom MCP server.
Open Settings
Open Codex Desktop, click your profile icon in the bottom-left corner, then select Settings.
Go to MCPs
In Settings, click Plugins in the sidebar, then select the MCPs tab.
Add a server
Click + Add server in the top right.
Name the server
Enter the name below for the server and select the Streamable HTTP type.
Fastio 
Enter the MCP URL
Paste the MCP URL below into the URL field, leave Bearer token env var blank, then click Save.
https://mcp.fast.io/mcp/oauth 
Authenticate the connection
The fastio server now appears in your list. Click Authenticate to begin the sign-in flow.
Review permissions
You'll be redirected to Fastio to review permissions. Select your Access level and click Continue.
Approve access
Confirm your Fastio account details and click Approve to grant Codex access.
Auth complete
Your browser will confirm authorization is complete. Close this window and return to Codex Desktop.
Verify the connection
Back in Codex Desktop, ask something like "What can you tell me about my Fastio account?" to confirm the connection is working. Codex should return your account details.
Try these prompts
Copy and paste these into Codex to see Fastio 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 Codex 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 consolidated 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.
$29/mo ($24/mo annually). 14-day Business Trial first.
Monthly usage covers storage, bandwidth, and AI operations. Resets every 30 days.
FAQ
What is the Fastio MCP server?
It's a server that provides Codex with a consolidated set of workspace tools. By adding it to your config, Codex can upload files, create share links, and query documents using RAG.
How does authentication work?
The first time Codex uses a Fastio 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 Codex uploads?
Yes. Everything Codex stores is accessible at app.fast.io. You can browse, preview, comment on, and download files from any device.
Does this work with Codex CLI and Codex Desktop?
Yes. It works with both. For Codex Desktop, you add the MCP server in Settings. For Codex CLI, you add it with a single codex mcp add command. Both use the same OAuth sign-in flow, no manual config editing required.
What are the usage limits on the plans?
Fastio starts with a 14-day Business Trial. Our Solo plan ($29/mo) includes 1 TB storage and 300,000 credits/mo. Business ($99/mo) includes 10 TB storage and 1,200,000 credits/mo. Growth ($299/mo) includes 50 TB storage and 4,500,000 credits/mo. Existing files and share links always remain accessible.
Can Codex share files with people who don't use Codex?
Yes. Share links are regular web URLs. Recipients open them in a browser and get previews, downloads, and commenting features without needing an account.
The Fastio CLI is also available as a standalone tool for Codex and ChatGPT workflows.
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 Codex a professional workspace
Enable the consolidated MCP toolset for Codex in minutes. Built-in shared workspaces, RAG search, and file sharing.