oauth2

🔐 OAuth2

OAuth 2.0 is the industry-standard protocol for authorization. OAuth 2.0 focuses on client developer simplicity while providing specific authorization flows for web applications, desktop applications, mobile phones, and living room devices. This is a RubyGem for implementing OAuth 2.0 clients (not servers) in Ruby applications.

Federated DVCS Repository	Status	Issues	PRs	Wiki	CI	Discussions
🧪 oauth-xx/oauth2 on GitLab	The Truth	💚	💚	💚	🏀 Tiny Matrix	➖
🧊 oauth-xx/oauth2 on CodeBerg	An Ethical Mirror (Donate)	➖	💚	➖	⭕️ No Matrix	➖
🐙 oauth-xx/oauth2 on GitHub	A Dirty Mirror	💚	💚	➖	💯 Full Matrix	➖
🤼 OAuth Ruby Google Group	"Active"	➖	➖	➖	➖	💚
🎮️ Discord Server		Let's	talk	about	this	library!

Upgrading Runtime Gem Dependencies

This project sits underneath a large portion of the authorization systems on the internet. According to GitHub's project tracking, which I believe only reports on public projects, 100,000+ projects, and 500+ packages depend on this project.

That means it is painful for the Ruby community when this gem forces updates to its runtime dependencies.

As a result, great care, and a lot of time, have been invested to ensure this gem is working with all the leading versions per each minor version of Ruby of all the runtime dependencies it can install with.

What does that mean specifically for the runtime dependencies?

We have 100% test coverage of lines and branches, and this test suite runs across a large matrix covering the latest patch for each of the following minor versions:

• MRI Ruby @ v2.3, v2.4, v2.5, v2.6, v2.7, v3.0, v3.1, v3.2, v3.3, v3.4, HEAD
  • NOTE: This gem will still install on ruby v2.2, but vanilla GitHub Actions no longer supports testing against it, so YMMV.
• JRuby @ v9.2, v9.3, v9.4, v10.0, HEAD
• TruffleRuby @ v23.1, v24.1, HEAD
• gem faraday @ v0, v1, v2, HEAD ⏩️ lostisland/faraday
• gem jwt @ v1, v2, v3, HEAD ⏩️ jwt/ruby-jwt
• gem logger @ v1.2, v1.5, v1.7, HEAD ⏩️ ruby/logger
• gem multi_xml @ v0.5, v0.6, v0.7, HEAD ⏩️ sferik/multi_xml
• gem rack @ v1.2, v1.6, v2, v3, HEAD ⏩️ rack/rack
• gem snaky_hash @ v2, HEAD ⏩️ oauth-xx/snaky_hash
• gem version_gem @ v1, HEAD ⏩️ oauth-xx/version_gem

The last two were extracted from this gem. They are part of the oauth-xx org, and are developed in tight collaboration with this gem.

Also, where reasonable, tested against the runtime dependencies of those dependencies:

• gem hashie @ v0, v1, v2, v3, v4, v5, HEAD ⏩️ hashie/hashie

You should upgrade this gem with confidence*.

• This gem follows a strict & correct (according to the maintainer of SemVer; more info) interpretation of SemVer.
  • Dropping support for any of the runtime dependency versions above will be a major version bump.
  • If you aren't on one of the minor versions above, make getting there a priority.
• You should upgrade the dependencies of this gem with confidence*.
• Please do upgrade, and then, when it goes smooth as butter please sponsor me. Thanks!

* MIT license; I am unable to make guarantees.

Quick Usage Example for AI and Copy / Pasting

Convert the following curl command into a token request using this gem...

curl --request POST \
  --url 'https://login.microsoftonline.com/REDMOND_REDACTED/oauth2/token' \
  --header 'content-type: application/x-www-form-urlencoded' \
  --data grant_type=client_credentials \
  --data client_id=REDMOND_CLIENT_ID \
  --data client_secret=REDMOND_CLIENT_SECRET \
  --data resource=REDMOND_RESOURCE_UUID

NOTE: In the ruby version below, certain params are passed to the get_token call, instead of the client creation.

OAuth2::Client.new(
  "REDMOND_CLIENT_ID", # client_id
  "REDMOND_CLIENT_SECRET", # client_secret
  auth_scheme: :request_body, # Other modes are supported: :basic_auth, :tls_client_auth, :private_key_jwt
  token_url: "oauth2/token", # relative path, except with leading `/`, then absolute path
  site: "https://login.microsoftonline.com/REDMOND_REDACTED",
). # The base path for token_url when it is relative
  client_credentials. # There are many other types to choose from!
  get_token(resource: "REDMOND_RESOURCE_UUID")

NOTE: header - The content type specified in the curl is already the default!

If any of the above makes you uncomfortable, you may be in the wrong place. One of these might be what you are looking for:

• OAuth 2.0 Spec
• doorkeeper gem for OAuth 2.0 server/provider implementation.
• oauth sibling gem for OAuth 1.0 implementations in Ruby.

💡 Info you can shake a stick at

Tokens to Remember
Works with JRuby
Works with Truffle Ruby
Works with MRI Ruby 3
Works with MRI Ruby 2
Source
Documentation
Compliance
Style
Support
Enterprise Support	💡Subscribe for support guarantees covering all FLOSS dependencies! 💡Tidelift is part of Sonar! 💡Tidelift pays maintainers to maintain the software you depend on! 📊@Pointy Haired Boss: An enterprise support subscription is "never gonna let you down", and supports open source maintainers!
Comrade BDFL 🎖️
... 💖	🧊 🐙 🛖 🧪

🚀 Release Documentation

Version 2.0.x

Older Releases

✨ Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add oauth2

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install oauth2

🔒 Secure Installation

oauth2 is cryptographically signed, and has verifiable SHA-256 and SHA-512 checksums by stone_checksums. Be sure the gem you install hasn’t been tampered with by following the instructions below.

Add my public key (if you haven’t already, expires 2045-04-29) as a trusted certificate:

gem cert --add <(curl -Ls https://raw.github.com/oauth-xx/oauth2/main/certs/pboling.pem)

You only need to do that once. Then proceed to install with:

gem install oauth2 -P MediumSecurity

The MediumSecurity trust profile will verify signed gems, but allow the installation of unsigned dependencies.

This is necessary because not all of oauth2’s dependencies are signed, so we cannot use HighSecurity.

If you want to up your security game full-time:

bundle config set --global trust-policy MediumSecurity

NOTE: Be prepared to track down certs for signed gems and add them the same way you added mine.

OAuth2 for Enterprise

Available as part of the Tidelift Subscription.

The maintainers of this and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source packages you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact packages you use. Learn more.

Security contact information

To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.

For more see SECURITY.md.

What is new for v2.0?

• Works with Ruby versions >= 2.2
• Drop support for the expired MAC Draft (all versions)
• Support IETF rfc7515 JSON Web Signature - JWS (since v2.0.12)
  • Support JWT kid for key discovery and management
• Support IETF rfc7523 JWT Bearer Tokens (since v2.0.0)
• Support IETF rfc7231 Relative Location in Redirect (since v2.0.0)
• Support IETF rfc6749 Don't set oauth params when nil (since v2.0.0)
• Support IETF rfc7009 Token Revocation (since v2.0.10)
• Support OIDC 1.0 Private Key JWT; based on the OAuth JWT assertion specification (RFC 7523)
• Support new formats, including from jsonapi.org: application/vdn.api+json, application/vnd.collection+json, application/hal+json, application/problem+json
• Adds option to OAuth2::Client#get_token:
  • :access_token_class (AccessToken); user specified class to use for all calls to get_token
• Adds option to OAuth2::AccessToken#initialize:
  • :expires_latency (nil); number of seconds by which AccessToken validity will be reduced to offset latency
• By default, keys are transformed to snake case.
  • Original keys will still work as previously, in most scenarios, thanks to snaky_hash gem.
  • However, this is a breaking change if you rely on response.parsed.to_h to retain the original case, and the original wasn't snake case, as the keys in the result will be snake case.
  • As of version 2.0.4 you can turn key transformation off with the snaky: false option.
• By default, the :auth_scheme is now :basic_auth (instead of :request_body)
  • Third-party strategies and gems may need to be updated if a provider was requiring client id/secret in the request body
• ... A lot more

Compatibility

Targeted ruby compatibility is non-EOL versions of Ruby, currently 3.2, 3.3, and 3.4. Compatibility is further distinguished as "Best Effort Support" or "Incidental Support" for older versions of Ruby. This gem will install on Ruby versions >= v2.2 for 2.x releases. See 1-4-stable branch for older rubies.

NOTE: The 1.4 series will only receive critical security updates. See SECURITY.md.

🔧 Basic Usage

Global Configuration

You can turn on additional warnings.

OAuth2.configure do |config|
  # Turn on a warning like:
  #   OAuth2::AccessToken.from_hash: `hash` contained more than one 'token' key
  config.silence_extra_tokens_warning = false # default: true
  # Set to true if you want to also show warnings about no tokens
  config.silence_no_tokens_warning = false # default: true,
end

The "extra tokens" problem comes from ambiguity in the spec about which token is the right token. Some OAuth 2.0 standards legitimately have multiple tokens. You may need to subclass OAuth2::AccessToken, or write your own custom alternative to it, and pass it in. Specify your custom class with the access_token_class option.

If you only need one token you can, as of v2.0.10, specify the exact token name you want to extract via the OAuth2::AccessToken using the token_name option.

You'll likely need to do some source diving. This gem has 100% test coverage for lines and branches, so the specs are a great place to look for ideas. If you have time and energy please contribute to the documentation!

authorize_url and token_url are on site root (Just Works!)

require "oauth2"
client = OAuth2::Client.new("client_id", "client_secret", site: "https://example.org")
# => #<OAuth2::Client:0x00000001204c8288 @id="client_id", @secret="client_sec...
client.auth_code.authorize_url(redirect_uri: "http://localhost:8080/oauth2/callback")
# => "https://example.org/oauth/authorize?client_id=client_id&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Foauth2%2Fcallback&response_type=code"

access = client.auth_code.get_token("authorization_code_value", redirect_uri: "http://localhost:8080/oauth2/callback", headers: {"Authorization" => "Basic some_password"})
response = access.get("/api/resource", params: {"query_foo" => "bar"})
response.class.name
# => OAuth2::Response

Relative authorize_url and token_url (Not on site root, Just Works!)

In above example, the default Authorization URL is oauth/authorize and default Access Token URL is oauth/token, and, as they are missing a leading /, both are relative.

client = OAuth2::Client.new("client_id", "client_secret", site: "https://example.org/nested/directory/on/your/server")
# => #<OAuth2::Client:0x00000001204c8288 @id="client_id", @secret="client_sec...
client.auth_code.authorize_url(redirect_uri: "http://localhost:8080/oauth2/callback")
# => "https://example.org/nested/directory/on/your/server/oauth/authorize?client_id=client_id&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Foauth2%2Fcallback&response_type=code"

Customize authorize_url and token_url

You can specify custom URLs for authorization and access token, and when using a leading / they will not be relative, as shown below:

client = OAuth2::Client.new(
  "client_id",
  "client_secret",
  site: "https://example.org/nested/directory/on/your/server",
  authorize_url: "/jaunty/authorize/",
  token_url: "/stirrups/access_token",
)
# => #<OAuth2::Client:0x00000001204c8288 @id="client_id", @secret="client_sec...
client.auth_code.authorize_url(redirect_uri: "http://localhost:8080/oauth2/callback")
# => "https://example.org/jaunty/authorize/?client_id=client_id&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Foauth2%2Fcallback&response_type=code"
client.class.name
# => OAuth2::Client

snake_case and indifferent access in Response#parsed

response = access.get("/api/resource", params: {"query_foo" => "bar"})
# Even if the actual response is CamelCase. it will be made available as snaky:
JSON.parse(response.body)         # => {"accessToken"=>"aaaaaaaa", "additionalData"=>"additional"}
response.parsed                   # => {"access_token"=>"aaaaaaaa", "additional_data"=>"additional"}
response.parsed.access_token      # => "aaaaaaaa"
response.parsed[:access_token]    # => "aaaaaaaa"
response.parsed.additional_data   # => "additional"
response.parsed[:additional_data] # => "additional"
response.parsed.class.name        # => SnakyHash::StringKeyed (from snaky_hash gem)

Serialization

As of v2.0.11, if you need to serialize the parsed result, you can!

There are two ways to do this, globally, or discretely. The discrete way is recommended.

Global Serialization Config

Globally configure SnakyHash::StringKeyed to use the serializer. Put this in your code somewhere reasonable (like an initializer for Rails).

SnakyHash::StringKeyed.class_eval do
  extend SnakyHash::Serializer
end

Discrete Serialization Config

Discretely configure a custom Snaky Hash class to use the serializer.

class MySnakyHash < SnakyHash::StringKeyed
  # Give this hash class `dump` and `load` abilities!
  extend SnakyHash::Serializer
end

# And tell your client to use the custom class in each call:
client = OAuth2::Client.new("client_id", "client_secret", site: "https://example.org/oauth2")
token = client.get_token({snaky_hash_klass: MySnakyHash})

Serialization Extensions

These extensions work regardless of whether you used the global or discrete config above.

There are a few hacks you may need in your class to support Ruby < 2.4.2 or < 2.6. They are likely not needed if you are on a newer Ruby. See response_spec.rb if you need to study the hacks for older Rubies.

class MySnakyHash < SnakyHash::StringKeyed
  # Give this hash class `dump` and `load` abilities!
  extend SnakyHash::Serializer

  #### Serialization Extentions
  #
  # Act on the non-hash values (including the values of hashes) as they are dumped to JSON
  # In other words, this retains nested hashes, and only the deepest leaf nodes become bananas.
  # WARNING: This is a silly example!
  dump_value_extensions.add(:to_fruit) do |value|
    "banana" # => Make values "banana" on dump
  end

  # Act on the non-hash values (including the values of hashes) as they are loaded from the JSON dump
  # In other words, this retains nested hashes, and only the deepest leaf nodes become ***.
  # WARNING: This is a silly example!
  load_value_extensions.add(:to_stars) do |value|
    "***" # Turn dumped bananas into *** when they are loaded
  end

  # Act on the entire hash as it is prepared for dumping to JSON
  # WARNING: This is a silly example!
  dump_hash_extensions.add(:to_cheese) do |value|
    if value.is_a?(Hash)
      value.transform_keys do |key|
        split = key.split("_")
        first_word = split[0]
        key.sub(first_word, "cheese")
      end
    else
      value
    end
  end

  # Act on the entire hash as it is loaded from the JSON dump
  # WARNING: This is a silly example!
  load_hash_extensions.add(:to_pizza) do |value|
    if value.is_a?(Hash)
      res = klass.new
      value.keys.each_with_object(res) do |key, result|
        split = key.split("_")
        last_word = split[-1]
        new_key = key.sub(last_word, "pizza")
        result[new_key] = value[key]
      end
      res
    else
      value
    end
  end
end

See response_spec.rb, or the oauth-xx/snaky_hash gem for more ideas.

What if I hate snakes and/or indifference?

response = access.get("/api/resource", params: {"query_foo" => "bar"}, snaky: false)
JSON.parse(response.body)         # => {"accessToken"=>"aaaaaaaa", "additionalData"=>"additional"}
response.parsed                   # => {"accessToken"=>"aaaaaaaa", "additionalData"=>"additional"}
response.parsed["accessToken"]    # => "aaaaaaaa"
response.parsed["additionalData"] # => "additional"
response.parsed.class.name        # => Hash (just, regular old Hash)

# will log both request and response, including bodies
ENV["OAUTH_DEBUG"] = "true"

require "oauth2"
client = OAuth2::Client.new(
  "client_id",
  "client_secret",
  site: "https://example.org",
  logger: Logger.new("example.log", "weekly"),
)

OAuth2::Response

The AccessToken methods #get, #post, #put and #delete and the generic #request will return an instance of the #OAuth2::Response class.

This instance contains a #parsed method that will parse the response body and return a Hash-like SnakyHash::StringKeyed if the Content-Type is application/x-www-form-urlencoded or if the body is a JSON object. It will return an Array if the body is a JSON array. Otherwise, it will return the original body string.

The original response body, headers, and status can be accessed via their respective methods.

OAuth2::AccessToken

If you have an existing Access Token for a user, you can initialize an instance using various class methods including the standard new, from_hash (if you have a hash of the values), or from_kvform (if you have an application/x-www-form-urlencoded encoded string of the values).

OAuth2::Error

On 400+ status code responses, an OAuth2::Error will be raised. If it is a standard OAuth2 error response, the body will be parsed and #code and #description will contain the values provided from the error and error_description parameters. The #response property of OAuth2::Error will always contain the OAuth2::Response instance.

If you do not want an error to be raised, you may use :raise_errors => false option on initialization of the client. In this case the OAuth2::Response instance will be returned as usual and on 400+ status code responses, the Response instance will contain the OAuth2::Error instance.

Authorization Grants

Currently, the Authorization Code, Implicit, Resource Owner Password Credentials, Client Credentials, and Assertion authentication grant types have helper strategy classes that simplify client use. They are available via the #auth_code, #implicit, #password, #client_credentials, and #assertion methods respectively.

These aren't full examples, but demonstrative of the differences between usage for each strategy.

auth_url = client.auth_code.authorize_url(redirect_uri: "http://localhost:8080/oauth/callback")
access = client.auth_code.get_token("code_value", redirect_uri: "http://localhost:8080/oauth/callback")

auth_url = client.implicit.authorize_url(redirect_uri: "http://localhost:8080/oauth/callback")
# get the token params in the callback and
access = OAuth2::AccessToken.from_kvform(client, query_string)

access = client.password.get_token("username", "password")

access = client.client_credentials.get_token

# Client Assertion Strategy
# see: https://tools.ietf.org/html/rfc7523
claimset = {
  iss: "http://localhost:3001",
  aud: "http://localhost:8080/oauth2/token",
  sub: "me@example.com",
  exp: Time.now.utc.to_i + 3600,
}
assertion_params = [claimset, "HS256", "secret_key"]
access = client.assertion.get_token(assertion_params)

# The `access` (i.e. access token) is then used like so:
access.token # actual access_token string, if you need it somewhere
access.get("/api/stuff") # making api calls with access token

If you want to specify additional headers to be sent out with the request, add a 'headers' hash under 'params':

access = client.auth_code.get_token("code_value", redirect_uri: "http://localhost:8080/oauth/callback", headers: {"Some" => "Header"})

You can always use the #request method on the OAuth2::Client instance to make requests for tokens for any Authentication grant type.

🔐 Security

See SECURITY.md.

🤝 Contributing

If you need some ideas of where to help, you could work on adding more code coverage, or if it is already 💯 (see below) check issues, or PRs, or use the gem and think about how it could be better.

We so if you make changes, remember to update it.

See CONTRIBUTING.md for more detailed instructions.

🚀 Release Instructions

See CONTRIBUTING.md.

Code Coverage

🪇 Code of Conduct

Everyone interacting with this project's codebases, issue trackers, chat rooms and mailing lists agrees to follow the .

🌈 Contributors

Made with contributors-img.

Also see GitLab Contributors: https://gitlab.com/oauth-xx/oauth2/-/graphs/main

⭐️ Star History

📌 Versioning

This Library adheres to . Violations of this scheme should be reported as bugs. Specifically, if a minor or patch version is released that breaks backward compatibility, a new version should be immediately released that restores compatibility. Breaking changes to the public API will only be introduced with new major versions.

📌 Is "Platform Support" part of the public API?

Yes. But I'm obligated to include notes...

SemVer should, but doesn't explicitly, say that dropping support for specific Platforms is a breaking change to an API. It is obvious to many, but not all, and since the spec is silent, the bike shedding is endless.

dropping support for a platform is both obviously and objectively a breaking change

• Jordan Harband (@ljharb, maintainer of SemVer) in SemVer issue 716

To get a better understanding of how SemVer is intended to work over a project's lifetime, read this article from the creator of SemVer:

• "Major Version Numbers are Not Sacred"

As a result of this policy, and the interpretive lens used by the maintainer, you can (and should) specify a dependency on these libraries using the Pessimistic Version Constraint with two digits of precision.

For example:

spec.add_dependency("oauth2", "~> 2.0")

See CHANGELOG.md for a list of releases.

📄 License

The gem is available as open source under the terms of the MIT License . See LICENSE.txt for the official Copyright Notice.

© Copyright

• Copyright (c) 2017–2025 Peter H. Boling, of Galtzo.com , and oauth2 contributors
• Copyright (c) 2011-2013 Michael Bleigh and Intridea, Inc.

🤑 One more thing

Having arrived at the bottom of the page, please endure a final supplication. The primary maintainer of this gem, Peter Boling, wants Ruby to be a great place for people to solve problems, big and small. Please consider supporting his efforts via the giant yellow link below, or one of smaller ones, depending on button size preference.

P.S. Use the gem => Discord for help