API stands for Application Programming Interface. It's a defined set of rules that says what one piece of software will accept as input and what it will send back. In practice, that usually means a system sending a request over the internet and getting structured data (commonly JSON) in return.
What an API does
An API draws a clear boundary between systems. One side exposes a set of operations ("get this customer's orders", "create a new invoice", "check if this address exists"), and the other side calls those operations without needing to know how they're implemented internally. That separation is what lets a website talk to a payment provider, a mobile app talk to its backend, or an AI tool plug into existing business software.
What APIs are used for
Connecting a website or app to a payment provider, CRM, or accounting package
Letting internal systems (an ERP, a customer portal) share data automatically instead of manual exports
Powering mobile apps that need the same data as a web platform
Plugging AI tools and LLMs into existing software
What to get right
Building a solid API is more than exposing data. Authentication (who is allowed to call it), rate limiting (how much they're allowed to call it), versioning (what happens when it changes), and documentation (how anyone else knows how to use it) all determine whether an API is actually usable a year from now, by your own team or someone else's.
Vulpo and API
Nearly everything we build talks to something else. We design and build APIs for our own Laravel applications, and we integrate with the APIs of payment providers, CRMs, and other third-party tools our clients already depend on.
