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Cap stores all video files, thumbnails, and assets in S3-compatible object storage. This guide covers configuration for various S3 providers.

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Storage Providers

Cap works with any S3-compatible storage:

MinIO (Default)

Included in Docker Compose, runs locally

AWS S3

Industry standard, global CDN

Cloudflare R2

Zero egress fees, fast globally

Backblaze B2

Most cost-effective option

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MinIO (Default Setup)

The Docker Compose deployment includes MinIO out of the box.

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Configuration

Default environment variables:
.env
# MinIO Credentials
MINIO_ROOT_USER=capadmin
MINIO_ROOT_PASSWORD=your-secure-password

# Cap S3 Configuration
CAP_AWS_BUCKET=cap
CAP_AWS_REGION=us-east-1
CAP_AWS_ACCESS_KEY=capadmin
CAP_AWS_SECRET_KEY=your-secure-password
S3_PUBLIC_ENDPOINT=http://localhost:9000
S3_INTERNAL_ENDPOINT=http://minio:9000
S3_PATH_STYLE=true

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Access MinIO Console

MinIO includes a web-based admin console: 
http://localhost:9001
Login with:
  • Username: Value of MINIO_ROOT_USER
  • Password: Value of MINIO_ROOT_PASSWORD

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Production MinIO Setup

For production with public access:
1

Configure Domain

Point a subdomain to your server:
s3.yourdomain.com → Your server IP
2

Update Environment Variables

.env
S3_PUBLIC_ENDPOINT=https://s3.yourdomain.com
3

Configure Reverse Proxy

See SSL/HTTPS Setup for Nginx/Caddy configuration.
4

Test Access

Videos should now be accessible at:
https://s3.yourdomain.com/cap/video-id.mp4

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MinIO Limitations

MinIO on Docker has limitations for production:
  • Single point of failure
  • No automatic backups
  • Limited to server disk space
  • No built-in CDN
Consider external S3 for production deployments.

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AWS S3

AWS S3 is the most reliable option with global CDN through CloudFront.

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Setup Steps

1

Create S3 Bucket

  1. Go to AWS S3 Console
  2. Click Create bucket
  3. Configure:
    • Bucket name: cap-videos-prod (must be globally unique)
    • Region: Choose closest to your users
    • Block Public Access: Disable (we’ll set specific permissions)
  4. Create bucket
2

Configure Bucket Policy

Allow public read access for videos:
  1. Go to bucket Permissions → Bucket Policy
  2. Add this policy:
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "PublicReadGetObject",
      "Effect": "Allow",
      "Principal": "*",
      "Action": "s3:GetObject",
      "Resource": "arn:aws:s3:::cap-videos-prod/*"
    }
  ]
}
Replace cap-videos-prod with your bucket name.
3

Enable CORS

Allow browser access from your domain:
  1. Go to Permissions → CORS configuration
  2. Add:
[
  {
    "AllowedHeaders": ["*"],
    "AllowedMethods": ["GET", "PUT", "POST", "DELETE"],
    "AllowedOrigins": ["https://cap.yourdomain.com"],
    "ExposeHeaders": ["ETag"]
  }
]
4

Create IAM User

  1. Go to IAM Console
  2. Click Users → Add user
  3. User name: cap-s3-user
  4. Access type: Programmatic access
  5. Attach policy: AmazonS3FullAccess (or create custom policy below)
  6. Save Access Key ID and Secret Access Key
Custom policy (more secure):
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "s3:PutObject",
        "s3:GetObject",
        "s3:DeleteObject",
        "s3:ListBucket"
      ],
      "Resource": [
        "arn:aws:s3:::cap-videos-prod",
        "arn:aws:s3:::cap-videos-prod/*"
      ]
    }
  ]
}
5

Configure Cap

Update your .env file:
.env
CAP_AWS_BUCKET=cap-videos-prod
CAP_AWS_REGION=us-east-1
CAP_AWS_ACCESS_KEY=AKIAIOSFODNN7EXAMPLE
CAP_AWS_SECRET_KEY=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
S3_PUBLIC_ENDPOINT=https://s3.amazonaws.com
S3_PATH_STYLE=false
Remove MinIO from docker-compose.yml (optional).
6

Restart Cap

docker compose down
docker compose up -d

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CloudFront CDN (Optional)

Add CloudFront for faster global delivery:
1

Create Distribution

  1. Go to CloudFront Console
  2. Click Create Distribution
  3. Configure:
    • Origin Domain: Select your S3 bucket
    • Viewer Protocol Policy: Redirect HTTP to HTTPS
    • Allowed HTTP Methods: GET, HEAD, OPTIONS, PUT, POST, PATCH, DELETE
    • Cache Policy: CachingOptimized
2

Update Cap Configuration

.env
CAP_AWS_BUCKET_URL=https://d111111abcdef8.cloudfront.net
Or use custom domain:
.env
CAP_AWS_BUCKET_URL=https://cdn.yourdomain.com

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Cloudflare R2

Cloudflare R2 offers S3-compatible storage with zero egress fees.
1

Create R2 Bucket

  1. Go to Cloudflare Dashboard → R2
  2. Click Create bucket
  3. Name: cap-videos
  4. Location: Automatic (or choose region)
2

Enable Public Access

  1. Go to bucket Settings
  2. Click Allow Access under “Public Access”
  3. Cloudflare provides a public URL: 
    https://pub-xxxxxx.r2.dev
3

Create API Token

  1. Go to R2 → Manage R2 API Tokens
  2. Click Create API Token
  3. Permissions:
    • Object Read & Write
    • Apply to specific bucket: cap-videos
  4. Save Access Key ID and Secret Access Key
4

Configure Cap

.env
CAP_AWS_BUCKET=cap-videos
CAP_AWS_REGION=auto
CAP_AWS_ACCESS_KEY=your-r2-access-key-id
CAP_AWS_SECRET_KEY=your-r2-secret-key
S3_PUBLIC_ENDPOINT=https://pub-xxxxxx.r2.dev
S3_INTERNAL_ENDPOINT=https://xxxxxx.r2.cloudflarestorage.com
S3_PATH_STYLE=true
Find the internal endpoint in R2 bucket settings.
5

Custom Domain (Optional)

  1. Go to bucket Settings → Custom Domains
  2. Add: cdn.yourdomain.com
  3. Add CNAME record in Cloudflare DNS: 
    cdn.yourdomain.com → pub-xxxxxx.r2.dev
  4. Update Cap:
    .env
    S3_PUBLIC_ENDPOINT=https://cdn.yourdomain.com
R2 is significantly cheaper than S3 for high-traffic deployments due to zero egress fees.

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Backblaze B2

Backblaze B2 is the most cost-effective S3-compatible storage.
1

Create Bucket

  1. Sign up at backblaze.com
  2. Go to Buckets → Create a Bucket
  3. Configure:
    • Bucket Name: cap-videos
    • Files in Bucket: Public
    • Encryption: Disable
2

Create Application Key

  1. Go to App Keys → Add a New Application Key
  2. Name: cap-server
  3. Access: Read and Write
  4. Bucket: cap-videos
  5. Save keyID and applicationKey
3

Get Endpoint URL

In bucket details, find:
  • Endpoint: s3.us-west-004.backblazeb2.com
  • Region: us-west-004
4

Configure Cap

.env
CAP_AWS_BUCKET=cap-videos
CAP_AWS_REGION=us-west-004
CAP_AWS_ACCESS_KEY=your-key-id
CAP_AWS_SECRET_KEY=your-application-key
S3_PUBLIC_ENDPOINT=https://s3.us-west-004.backblazeb2.com
S3_PATH_STYLE=true

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Backblaze Pricing

  • Storage: 6/TB/month(vs6/TB/month (vs 23/TB for S3)
  • Downloads: First 3x storage is free, then $0.01/GB
  • API calls: Included

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Other S3 Providers

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DigitalOcean Spaces

.env
CAP_AWS_BUCKET=cap-videos
CAP_AWS_REGION=nyc3
CAP_AWS_ACCESS_KEY=your-spaces-key
CAP_AWS_SECRET_KEY=your-spaces-secret
S3_PUBLIC_ENDPOINT=https://nyc3.digitaloceanspaces.com
S3_PATH_STYLE=true

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Wasabi

.env
CAP_AWS_BUCKET=cap-videos
CAP_AWS_REGION=us-east-1
CAP_AWS_ACCESS_KEY=your-wasabi-key
CAP_AWS_SECRET_KEY=your-wasabi-secret
S3_PUBLIC_ENDPOINT=https://s3.wasabisys.com
S3_PATH_STYLE=true

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Linode Object Storage

.env
CAP_AWS_BUCKET=cap-videos
CAP_AWS_REGION=us-east-1
CAP_AWS_ACCESS_KEY=your-linode-key
CAP_AWS_SECRET_KEY=your-linode-secret
S3_PUBLIC_ENDPOINT=https://us-east-1.linodeobjects.com
S3_PATH_STYLE=true

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Testing Storage Configuration

Verify your S3 setup:
1

Upload Test Video

Record and upload a video using Cap Desktop.
2

Check Logs

docker compose logs cap-web | grep -i s3
Look for successful upload messages.
3

Verify Public Access

Open the video share link. If the video plays, S3 is configured correctly.
4

Check Bucket

Log in to your S3 provider console and verify files are being uploaded.

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Troubleshooting

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Videos Won’t Upload

Check credentials: 
docker compose logs cap-web | grep -i "access denied\|unauthorized"
Verify:
  • CAP_AWS_ACCESS_KEY and CAP_AWS_SECRET_KEY are correct
  • IAM user has PutObject permission

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Videos Upload but Won’t Play

Public access issue:
  1. Verify bucket policy allows public read
  2. Check CORS configuration includes your domain
  3. Test direct file URL in browser
Fix for S3: 
{
  "Effect": "Allow",
  "Principal": "*",
  "Action": "s3:GetObject",
  "Resource": "arn:aws:s3:::your-bucket/*"
}

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CORS Errors in Browser

Update CORS configuration to include your Cap domain: 
[
  {
    "AllowedOrigins": ["https://cap.yourdomain.com"],
    "AllowedMethods": ["GET", "PUT", "POST"],
    "AllowedHeaders": ["*"]
  }
]

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Wrong Endpoint

Check logs for connection errors: 
docker compose logs cap-web | grep -i endpoint
Verify:
  • S3_PUBLIC_ENDPOINT is accessible from browser
  • S3_INTERNAL_ENDPOINT is accessible from Docker container
  • S3_PATH_STYLE matches your provider

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Migration Between Providers

Move videos from one S3 provider to another:
1

Install AWS CLI or rclone

# AWS CLI
pip install awscli

# Or rclone (recommended)
curl https://rclone.org/install.sh | sudo bash
2

Configure Source and Destination

For rclone, configure both providers:
rclone config
Create remotes for source and destination.
3

Copy Files

# Using rclone
rclone copy source:cap-bucket dest:cap-bucket --progress

# Using AWS CLI (S3 to S3)
aws s3 sync s3://old-bucket s3://new-bucket
4

Update Cap Configuration

Update .env with new S3 credentials and restart:
docker compose down
docker compose up -d
5

Verify

Test that old videos still play with new S3 endpoint.

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Cost Comparison

Monthly costs for 1TB storage + 1TB egress:
ProviderStorageEgressTotal
MinIO (self-hosted)Server cost$0~$20-50
AWS S3$23$90$113
Cloudflare R2$15$0$15
Backblaze B2$6$0*$6
Wasabi$6.99$0*$6.99
*Free egress up to limits
For high-traffic deployments, Cloudflare R2 or Backblaze B2 offer the best value.

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Next Steps

Environment Variables

Complete S3 variable reference

SSL/HTTPS

Secure S3 endpoints with SSL

Scaling

Optimize storage for production

Troubleshooting

Debug storage issues

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