What is API integration and why does it matter?

An API (Application Programming Interface) defines which information an application can share with another application, and under which rules. It lets two systems do between themselves, safely and consistently, what a person would otherwise do on a screen.

An everyday example

Think of a request form. When it is submitted, the information lands in an email; someone reads it and types the details into a tracking system by hand. With an API integration, the form records the information directly in the tracking system, a notification goes to the right person and the record number is sent back to whoever filled in the form. There is no copying, retyping or overlooking in between.

What integration brings

• A single source of data. Because the same information is not typed into several places, inconsistencies decrease.
• Time. Records are transferred immediately; there is no need to wait for the end of the day or a batch transfer.
• Traceability. Which data came from which system, and when, is on record.
• Flexibility. When one system changes, only the connection point is updated; the whole process does not have to be rebuilt.

What to look at when planning

Data mapping. Two systems may keep the same information under different names or formats. A field called “customer code” in one may be “account number” in the other. Which field maps to which should be written down.

Direction and frequency. Will data flow one way, or will the two systems update each other? Will transfers be immediate or at set intervals? Two-way synchronisation needs conflict rules.

Failure handling. Decide in advance what happens when the other system does not respond: is the record queued, who is notified and how are retries handled?

Permissions. The account used for the integration should only reach the data it needs. Connections set up with a fully privileged administrator account carry unnecessary risk.

Version changes. Applications update their APIs over time. Document which version the integration relies on and how changes will be tracked.

What if there is no API?

Not every application offers an open API. In that case, file transfers, database-level reading or the export tools the application provides are considered. These methods can work, but they are more fragile and need careful monitoring. When choosing a new application, whether it offers an open, documented API should be an important selection criterion.