Design the API structure

Once completed, the data model can be used to draft one or more APIs. A draft API may cover a simple data model fully, or parts of a more complex model.

API First is a development strategy in which the API is designed before the actual coding starts. This ensures that the API will be the foundation of the entire information system around which the other components are built. A clear specification at the start promotes information system interoperability and enables different development teams to work in parallel in the implementation phase that follows the specification stage.

The API First model is particularly useful in complex procurements as it divides the whole into manageable parts. This allows different teams to develop their components simultaneously.

Benefits of the API First model:

• Interoperability: The API is specified first, which facilitates interplay between information systems.
• Agile development: Teams can work simultaneously to speed up the project.
• Scalability: Expanding and maintaining information systems is easier.

This practice is also referred to as the 'all finished except the actual work' approach, as the draft API can be used to collect feedback even before the actual coding starts. The organisation’s internal and external stakeholders can comment on interface descriptions.

Many free and commercial API management tools have been designed to support the API First model, making it easy to implement. Most tools can automatically generate a significant portion of the program code based on the API description, which significantly reduces the remaining coding effort. This also reduces the number of errors.

When a procurement is made for the use of a single organisation only, the APIs may be forgotten about. The need to import and export data to and from the information system may not be understood in the procurement phase.

A turnkey delivery of standard software may include everything but the APIs that will be needed to improve work efficiency and productivity. Software data models may also be protected by industrial rights, in which case adding an API may be expensive or even impossible.

The opposite of the API First model is the as needed model, in which the APIs are only implemented when they are needed. If the importance of the APIs is not understood from the outset, their implementation will be avoided and seen as just technical solutions.

The downsides of the as needed model include:

• Agility of development work and the API will be lost.
• Further development and competitive tendering will be more difficult.
• Can easily lead to extra work and temporary solutions.

Read more: The value and significance of Public Administration API Principles from the viewpoint of Finnish public organizations (Alila, University of Tampere, 2023) In Finnish with English abstract.Opens in a new window.