Setup Guide: Upload to Spaces Skill

This is part of my Postbox workflow — when I’m writing and need to include a screenshot, I don’t want to leave the terminal. Open a browser, upload somewhere, copy a URL, paste it back… that breaks the flow.

So I made a small skill that uploads a file to DigitalOcean Spaces and gives me a public URL I can drop straight into Markdown. Upload, get link, keep writing.

This guide covers the technical setup: configuring s3cmd and creating the Claude Code skill.

What follows is the step-by-step setup.

Part 1: Install and Configure s3cmd

s3cmd is a lightweight CLI for interacting with S3-compatible storage, which includes DigitalOcean Spaces.

Step 1: Install s3cmd

On macOS:

brew install s3cmd

Verify it’s installed:

s3cmd --version

Step 2: Get Your Spaces Credentials

1. Go to DigitalOcean Control Panel → API → Spaces Keys
2. Click Generate New Key
3. Copy both the Access Key and Secret Key

You can scope the key to:

• All Spaces, or
• A specific bucket (recommended)

Both options work for this setup.

Step 3: Configure s3cmd

Run the interactive configuration wizard:

s3cmd --configure

Example values for a bucket in nyc3 (adjust if you’re using another region):

Save the configuration when prompted.

Step 4: Test the Configuration (Important Gotcha)

During setup, s3cmd will try to list all buckets in your account. If your key is scoped to a specific bucket, you’ll likely see:

ERROR: Test failed: 403 (AccessDenied): Access Denied.
ERROR: Are you sure your keys have s3:ListAllMyBuckets permissions?

This is expected.

Scoped keys can’t list all buckets, but they can still access the bucket you allowed. Save the configuration anyway.

Step 5: Verify Access to Your Bucket

Test access directly against your bucket:

s3cmd ls s3://postbox/

If this works, your Spaces setup is complete.

Part 2: Create the Claude Code Skill

Now we wire this into Claude Code so uploads feel like a single command.

Step 1: Create the Command File

Create a new file:

~/.claude/commands/upload-to-spaces.md

Add the following content:

# Upload to Spaces

Upload a file to DigitalOcean Spaces and return the public URL.

## Arguments
$ARGUMENTS

## Instructions

1. Parse the arguments to find the file path to upload
2. Verify the file exists
3. Generate a unique filename by prepending a short UUID (8 chars) to the original filename
4. Upload the file using:
   s3cmd put "<filepath>" "s3://postbox/<unique-filename>" -P
5. Construct and return the public URL:
   https://postbox.nyc3.digitaloceanspaces.com/<unique-filename>
6. Display the URL prominently so it can be copied

Notes:

• The -P flag makes the file publicly accessible
• The UUID prefix avoids filename collisions
• Adjust the bucket name and region to match your setup

Step 2: Use the Skill

In Claude Code, you can now run:

/upload-to-spaces /path/to/image.png

Or describe it naturally:

upload this screenshot to spaces: ~/Desktop/screenshot.png

Claude will upload the file and return the public URL, ready to paste into Markdown.

Configuration Reference

Example setup used in this guide:

• Bucket: postbox
• Region: nyc3
• Endpoint: nyc3.digitaloceanspaces.com
• Public URL format:

https://postbox.nyc3.digitaloceanspaces.com/<filename>

Useful s3cmd Commands

# List files in a bucket
s3cmd ls s3://postbox/

# Upload a file (public)
s3cmd put myfile.png s3://postbox/ -P

# Upload with a custom name
s3cmd put myfile.png s3://postbox/custom-name.png -P

# Delete a file
s3cmd del s3://postbox/filename.png

# Inspect a file
s3cmd info s3://postbox/filename.png

That’s it.

You now have a small, reusable building block: upload a file from Claude and immediately get a public URL, without leaving the flow you’re already in.