How to Publish a Ruby Gem to RubyGems.org

To publish a gem to RubyGems, first build your gem package using gem build your_gem.gemspec. Then, push it to RubyGems.org with gem push your_gem-version.gem after logging in with gem signin or gem push will prompt you to enter your credentials.

Syntax

Publishing a gem involves two main commands:

• gem build your_gem.gemspec: Creates the gem package file (.gem) from your gemspec.
• gem push your_gem-version.gem: Uploads the built gem to RubyGems.org.

You must have an account on RubyGems.org and be logged in via the command line before pushing.

bash

gem build your_gem.gemspec
gem push your_gem-0.1.0.gem

Example

This example shows how to build and publish a gem named hello_world version 0.1.0.

bash

gem build hello_world.gemspec
# Output:  Successfully built RubyGem
#         Name: hello_world
#         Version: 0.1.0
#         File: hello_world-0.1.0.gem

gem push hello_world-0.1.0.gem
# Output: Pushing gem to RubyGems.org...
#         Successfully registered gem: hello_world (0.1.0)

Output

Successfully built RubyGem
Name: hello_world
Version: 0.1.0
File: hello_world-0.1.0.gem
Pushing gem to RubyGems.org...
Successfully registered gem: hello_world (0.1.0)

Common Pitfalls

• Not having a valid .gemspec file or missing required fields like name, version, and summary.
• Trying to push without logging in first; use gem signin or push will prompt for credentials.
• Version conflicts if you try to push a gem version that already exists on RubyGems.org.
• Forgetting to build the gem before pushing.

bash

## Wrong: Trying to push without building

gem push hello_world-0.1.0.gem

## Right: Build first, then push

gem build hello_world.gemspec
gem push hello_world-0.1.0.gem

Quick Reference

• Create or update your .gemspec file with correct metadata.
• Run gem build your_gem.gemspec to package your gem.
• Login with gem signin or push directly and enter credentials when prompted.
• Run gem push your_gem-version.gem to publish.
• Check your gem page on RubyGems.org to confirm publishing.

Key Takeaways

Always build your gem with gem build before pushing.

You must have a RubyGems.org account and be logged in to publish.

Ensure your gemspec file has all required fields filled correctly.

Avoid pushing a gem version that already exists to prevent errors.

Use gem push to upload your gem package to RubyGems.org.