Question detecting the edge of a collider

i have an "ai" if you can call it intelligent. that basicly follows the player where ever he goes. im gonna eventually make this into a boss. but i need the boss to detect the edge of colliders aka the floor. the floor is suspended above spikes and he cant fall in. i literally have no idea how to start coding this in.
i had an idea of making a circle collider at its feet and add an ontriggerexit so when it leaves the floor collider it sends back a message to stop the ai. but this seems pretty janky so im trying to find something else.

 

You could try to use a NavMesh to find areas which are walkable, which will also help with pathfinding supposing your character is behind a pillar or something.

 

ok ill check it out