Wrangler R2 Guide

Wrangler R2 Guide

Manage Cloudflare R2 object storage using the Wrangler CLI. R2 provides S3-compatible storage with zero egress fees.

Prerequisites

# Install Wrangler CLI
npm install -g wrangler

# Authenticate
wrangler login

# Verify authentication
wrangler whoami

Bucket Operations

List Buckets

wrangler r2 bucket list

Create Bucket

wrangler r2 bucket create bucket-name

Get Bucket Info

wrangler r2 bucket info bucket-name

Delete Bucket

wrangler r2 bucket delete bucket-name

Object Operations

IMPORTANT: By default, Wrangler uses local development storage. Use --remote flag for cloud operations.

Upload File

# Upload to remote (production)
wrangler r2 object put bucket-name/​path/​to/​file.png --file=local/​file.png --remote

# Upload with content type
wrangler r2 object put bucket-name/​image.jpg --file=image.jpg --content-type=image/​jpeg --remote

Bulk Upload

# Upload all PNG files
for file in *.png; do
  wrangler r2 object put "bucket-name/​images/​$file" --file="$file" --remote
done

Download File

wrangler r2 object get bucket-name/​path/​to/​file.png --file=downloaded.png --remote

Delete File

wrangler r2 object delete bucket-name/​path/​to/​file.png --remote

Public Access Configuration

Enable Public URL (r2.dev subdomain)

wrangler r2 bucket dev-url enable bucket-name -y

Check Public URL Status

wrangler r2 bucket dev-url get bucket-name

Example output:

Public access is enabled at 'https://pub-abc123.r2.dev'

Disable Public URL

wrangler r2 bucket dev-url disable bucket-name

Test Public Access

# Test with curl
curl -I "https://pub-abc123.r2.dev/​path/​to/​file.png"

# Should return HTTP 200 OK with Content-Type header

Custom Domain Setup

List Custom Domains

wrangler r2 bucket domain list bucket-name

Add Custom Domain

1. Add CNAME in DNS:

   assets.example.com CNAME bucket-name.r2.cloudflarestorage.com
   

2. Connect domain via Cloudflare Dashboard (not available via CLI in this Wrangler version)

CORS Configuration

List CORS Rules

wrangler r2 bucket cors list bucket-name

Set CORS Rules

Create cors.json:

{
  "CORSRules": [
    {
      "AllowedOrigins": ["*"],
      "AllowedMethods": ["GET"],
      "AllowedHeaders": ["*"],
      "MaxAgeSeconds": 3600
    }
  ]
}

Apply CORS:

wrangler r2 bucket cors set bucket-name cors.json

Delete CORS Rules

wrangler r2 bucket cors delete bucket-name

Common Workflows

Upload Images for AI Reference

cd image-directory

# Upload all images to image-refs/ path
for file in IMG_*.png; do
  echo "Uploading $file..."
  wrangler r2 object put "bucket-name/​image-refs/​$file" --file="$file" --remote
done

# Verify uploads
curl -I "https://pub-abc123.r2.dev/​image-refs/​IMG_0821.png"

Replace/​Update Files

# Simply re-upload to overwrite
wrangler r2 object put "bucket-name/​path/​file.png" --file=new-file.png --remote

Troubleshooting

"Resource location: local" Warning

Symptom: Upload succeeds but files not in cloud bucket

Solution: Add --remote flag to all commands:

wrangler r2 object put bucket-name/​file.png --file=file.png --remote

Authentication Errors

# Re-authenticate
wrangler logout
wrangler login

Public URLs Return 404

Check:

1. Dev URL is enabled: wrangler r2 bucket dev-url get bucket-name
2. File path matches exactly (case-sensitive)
3. File was uploaded with --remote flag

CORS Issues in Browser

Symptom: Browser blocks requests even though URLs work in curl

Solution: Configure CORS rules (see CORS Configuration section)

Cost Considerations

R2 Pricing (2024):

• Storage: $0.015/​GB/​month
• Class A operations (write/​list): $4.50/​million
• Class B operations (read): $0.36/​million
• Egress: FREE (major advantage)

Example Cost (100 images, 150MB):

• Storage: ~$0.002/​month
• Operations: ~$0.01/​month
• Total: ~$0.02/​month

Security Best Practices

1. Separate buckets for public vs. private assets
2. Use dev-url for quick testing, custom domains for production
3. Configure CORS only when browser access is needed
4. Regular backups of critical assets
5. Monitor usage in Cloudflare Dashboard

Key Differences from Documentation

This version (4.24.3) syntax:

# Object operations
wrangler r2 object put bucket-name/​path --file=file --remote
wrangler r2 object get bucket-name/​path --file=output --remote
wrangler r2 object delete bucket-name/​path --remote

# Bucket info
wrangler r2 bucket info bucket-name

# Dev URL
wrangler r2 bucket dev-url get bucket-name
wrangler r2 bucket dev-url enable bucket-name -y

# CORS
wrangler r2 bucket cors list bucket-name

Newer versions may use different syntax - check wrangler r2 --help for your version.

Mystica Project Setup

Bucket: mystica-assets Public URL: https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/ Images Path: image-refs/

Upload images:

cd /​Users/​silasrhyneer/​Code/​new-mystica/​docs/​image-refs

for file in IMG_*.png; do
  wrangler r2 object put "mystica-assets/​image-refs/​$file" --file="$file" --remote
done

Use in scripts:

npx tsx scripts/​generate-image.ts \
  --type "Weapon" \
  --materials "fire,steel" \
  --provider gemini \
  -r "https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/​image-refs/​IMG_0821.png,https://pub-1f07f440a8204e199f8ad01009c67cf5.r2.dev/​image-refs/​IMG_2791.png"

Related Documentation

• Full R2 Guide: docs/​external/​r2-image-hosting.md
• AI Image Generation: .claude/​skills/​generate-item-image.md
• Cloudflare R2 Docs: https://developers.cloudflare.com/r2/
• Wrangler CLI Reference: https://developers.cloudflare.com/workers/wrangler/