Connect Codex to your S3 buckets with quickS3

quickS3 is also a remote S3 MCP server, so Codex can work with the files in your S3-compatible buckets: list folders, pull a file down, or upload something it just built. It only gets the quickS3 roles you pick when you approve it. File contents travel directly between Codex and your storage provider, and quickS3 never sees them.

This guide walks through the setup in the ChatGPT desktop app, where Codex runs in Work mode. If you prefer the terminal, the two CLI commands are at the end.

Before you start

You need:

• A quickS3 organization with at least one storage connection. If you don’t have one yet, follow the guide for your provider, e.g. AWS S3 or Cloudflare R2.
• A role for the agent. Codex can do exactly what the role allows and nothing more, so a dedicated role is the easy way to keep it narrow. In this guide we use a role called AI Agent that can read and write two buckets.

Step 1: Add the quickS3 marketplace

Codex installs plugins from marketplaces. The quickS3 one lives on GitHub.

1. Open Plugins in the sidebar.
2. Click Add in the top right corner and choose Add a marketplace.

3. In Source, enter QuickS3-com/skill. Leave Git ref and Sparse paths empty.
4. Click Add marketplace.

Step 2: Install the plugin

1. Back on the Plugins page, switch to the Personal tab.
2. Under QuickS3, click + next to the QuickS3 plugin.

The plugin bundles two things: the quickS3 MCP server at https://quicks3.com/mcp, and a skill that teaches Codex to list folders narrowly, download through single-use links, and upload without overwriting existing files.

Step 3: Authorize Codex in quickS3

Codex opens your browser on the quickS3 consent page. Sign in if you need to. The page shows:

• Client: the name Codex reports, and the local address it returns to once you approve.
• Organization: each client connection covers one organization. To connect a different one, switch organization from the menu at the top first.
• Roles to delegate: tick the roles Codex may use. Only your own roles are listed.
• Access lifetime: 30, 60, or 90 days. The grant expires on its own after that.

Pick the role and lifetime, then click Authorize Codex.

Step 4: Ask Codex about your files

Start a new task in Work mode. Type @, pick QuickS3, and ask something simple:

List the folders I can access in QuickS3.

Codex lists your connections, then the buckets and top-level folders the role can see:

From there, try real work:

• “Download the latest invoice PDF from the public bucket and summarize it.”
• “Upload dist/site.zip to the upload/ folder.”
• “What changed in the reports/ folder this week?”

What the agent can do

The quickS3 MCP server exposes six tools:

Tool	What it does
list_connections	Lists the storage connections the grant can see
list_buckets	Lists visible buckets on one connection
list_objects	Lists one folder level, paginated
create_download_link	Creates a single-use download link, valid 5 minutes
create_share_link	Creates a public share link for someone else, valid 5 minutes to 30 days
create_upload_url	Creates a presigned upload URL, valid 15 minutes, no overwrite by default

There’s no delete tool, and every call is checked against the roles you delegated, with the same deny-wins rules your teammates get.

Prefer the terminal?

With the Codex CLI, add the marketplace and install the plugin:

codex plugin marketplace add https://github.com/QuickS3-com/skill.git

codex plugin add quicks3@quicks3

Codex then opens the same quickS3 consent page as in Step 3.

Review or revoke access

Every approval is listed on the AI agents tab in quickS3, and at the bottom of the consent page, with its status and expiry date. Click Revoke to cut an agent off right away. Agent actions show up in the audit log separately from your teammates’ activity, and agents don’t count as users on your plan.

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Using Claude Code too? See Connect Claude Code to your S3 buckets with quickS3. New to quickS3? Sign up and connect your first bucket.

For maintained setup and troubleshooting, use the Codex documentation.