What are the most common API versioning mistakes?

1 Mistake 1: No versioning at all

One of the worst API versioning mistakes is to not version your API at all. This means that any change you make to your API can break existing clients or consumers, leading to frustration, complaints, and loss of trust. Moreover, you will have no way of tracking or documenting the evolution of your API, making it harder to maintain, debug, or test. To avoid this mistake, you should always use some form of versioning for your API, whether it is in the URL, the header, the query string, or the body.

2 Mistake 2: Breaking changes in minor versions

Another common API versioning mistake is to introduce breaking changes in minor versions. Breaking changes are changes that alter the functionality, structure, or behavior of your API in a way that requires clients or consumers to update their code or configuration. For example, removing an endpoint, changing a data type, or adding a required parameter are breaking changes. Minor versions are versions that only add new features or fix bugs without affecting the existing functionality or structure of your API. For example, adding a new endpoint, improving performance, or fixing a typo are minor changes. To avoid this mistake, you should follow the semantic versioning convention, which states that breaking changes should only occur in major versions, while minor versions should only introduce backward-compatible changes.

3 Mistake 3: Inconsistent versioning scheme

A third common API versioning mistake is to use an inconsistent versioning scheme. This means that you use different methods or formats to version your API across different endpoints, resources, or services. For example, you might use the URL for some endpoints, the header for others, and the query string for others. Or you might use different numbering systems, such as v1, v1.1, v2, or v1-beta, v1-alpha, v1-stable. This can cause confusion, inconsistency, and errors for both your clients and your developers. To avoid this mistake, you should use a consistent versioning scheme for your entire API, and document it clearly and transparently.

4 Mistake 4: Over-versioning or under-versioning

A fourth common API versioning mistake is to over-version or under-version your API. Over-versioning means that you create too many versions of your API, often for trivial or unnecessary reasons. This can result in fragmentation, duplication, and waste of resources and effort. Under-versioning means that you create too few versions of your API, often for fear of breaking compatibility or introducing complexity. This can result in stagnation, obsolescence, and loss of innovation and value. To avoid this mistake, you should balance the trade-offs between versioning and not versioning your API, and consider the impact and value of each change you make. You should also communicate and collaborate with your clients and stakeholders to understand their needs and expectations.

5 Mistake 5: Poor versioning documentation

A fifth common API versioning mistake is to have poor versioning documentation. This means that you do not provide enough or accurate information about the versions of your API, such as what they are, what they do, how they differ, and how to use them. This can lead to confusion, misunderstanding, and errors for your clients and consumers, as well as for your own developers and testers. To avoid this mistake, you should provide clear, comprehensive, and up-to-date documentation for each version of your API, using tools such as API specifications, changelogs, and release notes.