A better rubygem hosting experience.

Built from the ground up to be the most simple, fast, and secure way to self-host your gems.

By leveraging the scalibility and performance of Go, we provide a single binary that can be run without a dependency on ruby. Gemfast is built using the best of the Go ecosystem like Caddy, BoltDB, Prometheus, and Casbin.

Product Details


Licensed Gemfast servers contain the following functionality:

  • High performance rubygems API implemented in Go
  • Compatible with both bundler and the gem CLI
  • Host internal and external gems within your private network
  • Mirror and cache gems internally from any upstream gem host
  • Prevent users from installing gems with high or critical CVEs
  • Allow or deny gems matching a regular expression
  • Expose prometheus metrics at the web server and application level
  • Authenticate users directly with Gemfast or with GitHub OAuth


Detailed documentation on the installation and configuration of Gemfast is available in the Gemfast Wiki on GitHub.


Users who purchase Gemfast are eligible for email support from the developer of Gemfast.


Gemfast is currently distributed as a standalone Debian package that supports Ubuntu 20.04+ and Debian 10+ operating systems. When you purchase Gemfast, a license key will be emailed to you that can be applied to your server via a configuration file or environment variable.

Test licenses are available to customers who need to deploy Gemfast in an ephemeral or test environment for a limited period of time.

Note: Gemfast makes an outbound request at server startup to activate and verify license keys. If deploying to an airgapped environment, an offline key can be supplied for an additional fee.

Comparison to other popular Gem Servers

Feature Gemfast Gem in a Box Gemstash
RubyGems Mirror/Cache
Private Gem Hosting
Vulnerability Scanning
Official .deb packages
Allow/Deny List Gems
Dedicated Support
Access Control List Fine grained None Limited
Web Server Caddy with Automatic HTTPS None None
Auth JWT, GitHub OAuth None API Token
Metrics Prometheus None None
Dependencies None Ruby Ruby, SQLite or Postgres, Memcached


Free Version

Gemfast is available to use for free with a limited feature set. To use the free version, download and install the product following the documentation and start the server without providing a license key.

The free version of Gemfast supports private gem hosting and automatic HTTPS but does not include any authentication strategy, rubygems mirroring, or security features.

Paid Version

Gemfast licenses are available as an annual subscription. The license enables all Gemfast features for one server instance (example: One EC2 server deployment).


If you have not purchased a license, consider buying one now before installation.

Name Version OS Arch
gemfast-1.0.0-amd64.deb 1.0.0 Debian/Ubuntu amd64
gemfast-1.0.0-arm64.deb 1.0.0 Debian/Ubuntu arm64