Helping FOSS projects be more successful through clearly defined project data.


Contributing code

First, thanks for your interest in the code for ClearlyDefined. While much of the project’s focus is on getting, curating and upstreaming the data, that all takes some non-trivial code and infrastructure. You can get a sense of the system from the architecture guide. It has a high-level discussion of the major pieces and how they fit together. The various repos may also have more specific information about the particulars of their code.

Quick and easy complete local configuration

You can setup individual parts of the system to run locally. Each repo’s README has instructions on how to get setup with just that functionality. To get the entire system setup locally, follow these steps. You will end up with the crawler and service running locally, serving up the sample harvested data via the local website.

  1. Clone these four repos side by side:
  2. Install ScanCode by following the instructions provided on their site.
  3. Copy the full.env.json from this (service) repo up one directory level and name it env.json
  4. Edit this env.json file as follows:
    • Add a GitHub token to CURATION_GITHUB_TOKEN and CRAWLER_GITHUB_TOKEN. This enables you to login to the local website or call the service APIs. You can use the same token for both settings. The tokens need only minimal permissions and are used to call GitHub APIs to manage pull requests and get repo tags etc.
    • Set SCANCODE_HOME to be the location of your ScanCode install from above.
  5. In each of the code repos (i.e., website, service, and crawler), run npm install and npm start. You probably want to run in three separate shells so you can see the logging coming from each. Note that if you are a VS Code user, you can use the handy launch configs that come with the crawler and service repos – just hit F5.
  6. Point your browser at http://localhost:3000. You should see the ClearlyDefined website and be able to browse the data etc. If you login (top right corner), more functionality will light up.


If you are looking to contribute code/docs, thanks! All contributions should come in as pull requests. We do not have a CLA (Contributor License Agreement) nor do we do DCOs (Developer Certificate of Origin) rather we rely on the GitHub Terms of Service Contributions section which boils down to outbound license === inbound license.

From an operational point of view, most people do not have write permissions to the ClearlyDefined Git repos so should simply fork in their favored loctaion and do a PR when ready. For folks who do have write permissions, you can fork as well or you can create a branch and then do a PR. The branch naming convention we use is /. So, for example, the user `jeffmcaffer` might use `jm/fixSomeStuff` or `jeffmcaffer/someFix`.

Coding style

We try to use a consistent style across all elements of ClearlyDefined. Of course there are some variations because part of the system is in Node while another is React but for the most part the same principles apply.

  • Consistency – A consistently formatted, named, structured, … codebase is easier to work with. Look around at the other code and see how it is structured and formatted.
  • Minimal – Simplicity and minimalism in the algorithms, data structures and the code itself makes for simpler systems.
  • Factored – Small, single purpose functions and classes are easier to test and understand.
  • Automatic – Automated formatting and testing are real enablers.


Always a topic in code and ClearlyDefined is no different. Here we follow these conventions:

  • Semantic – Name, especially variable and property names, should have semantic value. Type-based names are frown up. For example set(newValue) is better than set(number). Functions should have clear semantic names that are durable across data/implementation refactorings. For example, readDefinition is better than readBlob in most cases.
  • camelCase – camelCasing is used for properties, variables, functions, … Classes use PascalCase
  • Text – Names should be full words with all the vowels and consonant. request over req. Similarly, single letter variable names should be avoided except in certain very well known cases like loop indexes (e.g., i).
  • _Private – Functions that are private to a class should be prefixed with an _ (underscore). Note that this convention is not well-practiced at the moment.

  • Negative names – Avoid negative names like disbleCache. Err, disbleCache = true means the cache is enabled? Now try if (!disableCache) ....


As a general rule all code should be formatted using prettier and the settings in the .prettierrc file in the repo. Here is a brief summary of the main points:

  • Spaces not tabs. ‘nuff said.
  • Minimal vertical white space. If you find you need to add blank lines to separate parts of a function, your code is likely doing too much. Refactor into more, simpler, functions.
  • No ; (semi-colons). Yeah, it’s a thing.
  • Single quotes ' over double " unless convention strongly indicates otherwise (e.g., JSON, JSX)
  • Omit unnecessary {}, () and returns . For example, => over => { return })


  • Exit early. Avoid deeply nested if/else structures. Test for the simple/error cases and exit the function as early as possible. Much easier to understand.
  • Use the language but don’t go nuts. JavaScript has a number of cool quirks that enable super dense code. Unfortunately, that can make for code that is hard to understand. Fortunately, if your code is factored as described above, you tend to have smaller, well-named functions and can use more of the language more clearly.

Contribution opportunities

The system as a whole is very young. The code should be considered pre-alpha – it’s enough to demonstrate the concepts and operation. As such there are many areas ripe for your help. Don’t let technology be a barrier. Several contributors with little to no Node or React experience have made very real contributions. For example, the website needs designers and people who can think deeply about the curation User Experience and workflow. No code at all! Of course, if you are a React expert, there are challenges for you too.

Each repo has a set of GitHub issues and typically several with Help wanted or Good first issue labels. Also look in the repos for a higher level view of the problem areas and a roadmap for where that repo’s function is going. Che

And of course, you can always ask on Discord or the mailing list.