You can eat canned spaghetti without cooking.
Canned spaghetti is already fully cooked when it's going through the canning process at the plant that makes it.
Most people prefer to heat the canned spaghetti up in the microwave or on the stove before eating it as it tastes better.
However you can simply open the can of spaghetti and eat it right out of the can.
I've eaten canned spaghetti and other canned meats and canned foods right out of the can before during a power outage and no way to heat up the food.
While I much prefer to eat the canned food and canned spaghetti after heating it up, there's no harm in eating it cold right out of the can.
Any canned foods including meats that you buy in stores are already cooked and can safely be eaten right from the can.
Even hot dogs that you buy are already cooked and ready to eat.
It's recommended to heat the canned spaghetti, hot dogs or other canned foods up but they can safely be eaten right out of the can without heating them up.