What's the role of the brain if decisions are handed down from the API? Couldn't we have made due with just the spine and a few extra parts of the brain. How does it communicate to the API? Is the API vulnerable to physical effects, being linked to the brain? All these considerations have been explored thoroughly since Descartes and dualism.
Obviously there is a lot of verified intelligent behavior on neural level we know about, like image processing, 3D reconstruction & mapping, motion planning, sound recognition, voice synthesis etc. And we more-less have some simplified models like that in the form of deep learning. So imagine brain as a sensor processing engine for inputs happening in the vicinity of a person inside "Simuverse". Even computing possible actions to take and attaching some utility value of each of them or starting upon acting on the best solution found so far already. Now for the decision process to be complete, brain passes results of this computation to the API that then invokes consciousness in the "soulspace" which is of another yet unknown quality, making the decision ;-) There is some interface latency of course, so some default actions are needed by brain, but consciousness can override them within 0.5s. Brain could be seen as an equivalent of cyberspace, consciousness might be coming from another principle we aren't aware of or don't have proper scientific devices to measure yet (if that is even possible).
Remember, each age views humans differently. Previous civilizations viewed humans first as based on magic, then hydraulics, then mechanics, then electricity, now we view them via lens of information processing, as our Zeitgeist dictates. It's likely people in 100 years will be laughing at us and our stupidity (hopefully they will be more advanced and not in a dark age), after they crack more things about Universe.
Obviously, this doesn't explain phenomena like brain exhibiting multiple different persons inside for patients with schizophrenia or when connection between left and right hemisphere is broken - some experiments shown people behave like as if there were multiple persons inside fighting with each other. Perhaps a bug in the nexus when there is a hash collision somewhere? 8-)
