How do you design a RESTful API that supports backwards compatibility?

2 Use semantic versioning

Another way to manage backward compatibility is to use semantic versioning, or SemVer. This is a convention that defines how to assign and increment version numbers based on the type and impact of changes. According to SemVer, a version number consists of three parts: major, minor, and patch. A major version change indicates a breaking change that is not compatible with previous versions. A minor version change indicates a new feature or enhancement that is backward compatible. A patch version change indicates a bug fix or improvement that is backward compatible. By following SemVer, you can communicate the compatibility level of your API to your clients and avoid unexpected errors.

3 Avoid breaking changes

To ensure backward compatibility, you should avoid breaking changes in your API. Breaking changes can include removing or renaming a resource, changing the data type of a field, adding a required parameter, or altering the error handling logic. To prevent breaking changes, you should adhere to certain design principles. For instance, use descriptive and consistent naming for resources, fields, and parameters. Additionally, adopt flexible and extensible data formats, such as JSON or XML, that can incorporate new or optional fields without disrupting the schema. Moreover, utilize default values and fallback mechanisms for missing or invalid parameters. Lastly, employ HTTP status codes and error messages to indicate success or failure of a request and provide clear guidance for troubleshooting.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?