API Blueprint vs OpenAPI: What are the differences?

Introduction

API Blueprint and OpenAPI are two popular specifications used to design and document APIs. While both serve the same purpose of defining and describing APIs, they have some key differences that set them apart.

1. Syntax: API Blueprint uses a Markdown-like syntax for defining API contracts, while OpenAPI uses JSON or YAML. This syntax difference can affect the readability and ease of use for developers, with API Blueprint being more human-friendly and OpenAPI providing more flexibility and machine-readability.

2. Data Types: API Blueprint has a limited set of data types for describing API parameters, such as string, number, boolean, and array. On the other hand, OpenAPI provides a wider range of data types, including integers, floats, doubles, date, date-time, and more. This difference in data types can play a role in accurately defining and validating API inputs and outputs.

3. Versioning: OpenAPI explicitly supports versioning of API definitions through its "info" object, allowing for easy management and documentation of different versions of an API. API Blueprint, on the other hand, does not have built-in support for versioning and relies on other mechanisms or conventions to handle versioning.

4. Tooling Ecosystem: OpenAPI has a larger and more mature tooling ecosystem compared to API Blueprint. There are various tools available for generating documentation, mocking APIs, testing, and code generation from OpenAPI specifications. While API Blueprint also has its own set of tools, the breadth and depth of the OpenAPI tooling ecosystem tend to be more extensive.

5. Extensibility: OpenAPI provides a higher degree of extensibility through the use of custom properties and extensions. This allows developers to add additional metadata or features to their API specifications, making it more flexible for specialized use cases. API Blueprint, on the other hand, has a more limited extensibility mechanism, which may restrict certain customization options.

6. Community Support: OpenAPI has a larger and more active community compared to API Blueprint. This means that there are more resources, tutorials, forums, and developer support available for OpenAPI. Additionally, the larger community also leads to more frequent updates and improvements to the OpenAPI specification itself.

In summary, API Blueprint and OpenAPI differ in terms of their syntax, data types, versioning support, tooling ecosystem, extensibility, and community support. These differences should be considered when choosing the appropriate API specification for a project.