presign

Copy files to S3-compatible object storage and generate presigned URLs for sharing.

Install

go install github.com/mpepping/presign/cmd/presign@latest

Or build from source:

make build

Usage

presign cp <file>... [s3://bucket/key]
presign sign <s3://bucket/key>
presign ls <s3://bucket[/prefix]>

cp copies one or more files to S3 and prints a presigned URL per file to stdout. sign generates a presigned URL for an object already in S3. ls lists objects in an S3 bucket.

Quick Start with Config File

Create ~/.config/presign.toml once:

default_bucket = "my-shared-files"
endpoint_url = "https://s3.example.com"
region = "us-east-1"
profile = "default"
path_style = true
expiry = "24h"

Then upload with minimal commands:

# Upload using all defaults from config
presign cp report.pdf

# Upload multiple files at once
presign cp *.pdf

# Override specific values via CLI
presign cp report.pdf -e 7d                          # Custom expiry
presign cp report.pdf s3://other-bucket/report.pdf  # Different bucket
presign cp report.pdf --endpoint-url https://other.s3.com  # Override endpoint

Examples

Upload and sign using the cp subcommand:

# Upload using default bucket from config
presign cp report.pdf

# Upload to a specific bucket and key
presign cp report.pdf s3://my-bucket/docs/report.pdf

# Custom expiry (default: 24h)
presign cp report.pdf -e 7d

# Copy URL to clipboard (macOS)
presign cp report.pdf | pbcopy

# Upload with custom endpoint and expiry
presign cp presentation.pptx --endpoint-url https://s3.backblazeb2.com -e 14d

# Upload with path-style addressing (for Minio, Hetzner, etc.)
presign cp backup.tar.gz --path-style

# Upload with specific AWS profile
presign cp data.csv -p production

# Upload multiple files to default bucket
presign cp *.csv

# Upload multiple files to a specific prefix
presign cp report.pdf slides.pptx s3://my-bucket/meeting/

Sign or resign files already in the remote using the sign subcommand:

# Generate a presigned URL for an existing object
presign sign s3://my-bucket/docs/report.pdf

# With custom expiry
presign sign s3://my-bucket/docs/report.pdf -e 7d

# Copy presigned URL to clipboard (macOS)
presign sign s3://my-bucket/docs/report.pdf | pbcopy

# With specific AWS profile and endpoint
presign sign s3://my-bucket/archive.tar.gz -p production --endpoint-url https://s3.example.com

List bucket contents using the ls subcommand:

# List objects under a prefix
presign ls s3://my-bucket/docs/

# List top-level contents of a bucket
presign ls s3://my-bucket/

# With specific AWS profile and endpoint
presign ls s3://my-bucket/docs/ -p production --endpoint-url https://s3.example.com

Flags

Flag	Short	Description
--bucket	-b	S3 bucket
--expiry	-e	URL expiry duration (e.g. 24h, 7d)
--endpoint-url		S3 endpoint URL
--region		AWS region
--profile	-p	AWS profile
--path-style		Use path-style addressing (required for S3-compatible stores like Minio, Hetzner, etc.)
--config	-c	Config file path
--verbose	-v	Verbose output
--content-type		Override content type (cp only)

Configuration

presign reads AWS credentials from ~/.aws/config and ~/.aws/credentials.

An optional config file at ~/.config/presign.toml can set defaults:

default_bucket = "my-shared-files"
expiry = "48h"
endpoint_url = "https://minio.example.com"
region = "us-east-1"
profile = "default"
path_style = true

Precedence: CLI flags > TOML config > AWS config > defaults

License

MIT