Why it matters
Your tools are silos exactly to the degree their APIs go unused. Whether your CRM, store, accounts and site can share data decides how much of your admin can ever be automated: which makes "does it have a good API" a purchasing question, not a technical footnote.
How it works
A system publishes endpoints ("get customers", "create invoice", "update order"), that other software calls with credentials. Automations chain these calls across tools; AI agents use them as hands. No API means no chain: a human copies and pastes instead.
What to do about it
When buying software, ask what its API exposes before you fall in love with its screens. The tools that connect cheaply now are the automations you won't have to fight for later.
