Automated dependency management for Ruby, JavaScript, Python, PHP and Java
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Dependabot Core

Dependabot Core is a collection of helper classes for automating dependency updating in Ruby, JavaScript, Python, PHP, Elixir and Java. It can also update git submodules and Docker files. Highlights include:

  • Logic to check for the latest version of a dependency that's resolvable given a project's other dependencies. That means tapping into the package manager's dependency resolution logic
  • Logic to generate updated manifest and lockfiles for a new dependency version
  • Logic to find changelogs, release notes, and commits for a dependency update

Dependabot Core is used by Dependabot.


To run Dependabot Core, you'll need Ruby, Python, PHP, Elixir and Node installed. The main library is written in Ruby, while JavaScript, Python, Elixir and PHP are required for dealing with updates for their respective languages.

Before running Dependabot Core, install dependencies for the core library and the helpers:

  1. bundle install
  2. cd helpers/yarn && yarn install && cd -
  3. cd helpers/npm && yarn install && cd -
  4. cd helpers/php && composer install && cd -
  5. cd helpers/python && pip install -r requirements.txt && cd -
  6. cd helpers/elixir && mix deps.get && cd -


Dependabot Core has helper classes for seven concerns. Where relevant, each concern will have a language-specific class.

Service Description
Dependabot::FileFetchers Fetches the relevant dependency files for a project (e.g., the Gemfile and Gemfile.lock). See the file fetchers for more details.
Dependabot::FileParsers Parses a dependency file and extracts a list of dependencies for a project. See the file parsers for more details.
Dependabot::UpdateCheckers Checks whether a given dependency is up-to-date. See the update checkers for more details.
Dependabot::FileUpdaters Updates a dependency file to use the latest version of a given dependency. See the file updaters for more details.
Dependabot::MetadataFinders Looks up metadata about a dependency, such as its GitHub URL. See the metadata finders for more details.
Dependabot::PullRequestCreator Creates a Pull Request to the original repo with the updated dependency file.
Dependabot::PullRequestUpdater Updates an existing Pull Request with new dependency files (e.g., to resolve conflicts).

Why is this open source?

As the name suggests, Dependabot Core is the core of Dependabot (the rest of the app is pretty much just a UI and database). If we were paranoid about someone stealing our business then we'd be keeping it under lock and key.

Dependabot Core is open source because we're more interested in it having an impact than we are in making a buck from it. We'd love you to use Dependabot, so that we can continue to develop it, but if you want to build and host your own version then this library should make doing so a lot easier.

If you use Dependabot Core then we'd love to hear what you build!


Dependabot and Dependabot Core started life as Bump and Bump Core, back when Harry and Grey were working at GoCardless. We remain grateful for the help and support of GoCardless in helping make Dependabot possible - if you need to collect recurring payments from Europe, check them out.