Is Tawassul Shirk?
There are many types of tawassul, from your question I sense that you are referring to توسل بالذات. Very few scholars call it shirk. Imam Abu Hanifa deemed it haram!, so did ibn Taymiyyah and the likes of Albani ra. Regarding categorizing it as shirk only extreme Salafis and “Jamiat Ishaat ut Tawheed” declare it shirk. Their basis of calling it shirk is 2 folds 1- Thinking the awliya can hear us from here. (Shirk fil Simaa( 2- Thinking that the awliya have some authority in the matters of God. These 2 points are extremely valid but those people that use tawassul do not beleive that the awliya are hearing neither do they beleive they can interfere in God’s matters. It is a separate issue for the extreme sufis, they regard tawassul in the afford mentioned sense. In some cases it becomes shirk and in other it is not.