The objective is to produce a specification that can be stored with the source code and can be used to locate files used by the DevOps process.
Existing DevOps tools make assumptions or are configured as webhooks, which are outside of the source code. By capturing the assumptions with the code, there is less risk of errors or missed processes.
The approach with the specification is to create a file in a specified format in .well-known/devops.json location within your source. The format has placeholders for various activities of DevOps.
The specification does not mandate the tools to use but provides a location in the json where configuration files and other files are located in the source folder structure.
This allows the source code to be portable and the resource to be rebuilt using the same tools and process.
Depending on your tools, there are various ways to get the benefits provided by the DevOps.json file.
The simplest case is if you have a simple setup and don't require complex tool, is to define a simple bash script file in source and name that source file as the install or refresh script.
This bash script's location is then saved to devops.json
See Tutorials for some ideas.
If you want consistency you can generate the devops.json file from a template and prefill the data based on your organisations preferred DevOps tools.
If you tools change or you import projects from other organisations or Open Source then the values can be changed per project without impacting existing projects.