One providing cover at home? Certainly right! (7)
I believe the answer is:
insurer
'one providing cover' is the definition.
(I've seen this before)
'home? certainly right' is the wordplay.
'home?' becomes 'in' ('he's home' can mean 'he's in').
'certainly' becomes 'sure' (synonyms).
'right' becomes 'R' (common abbreviation).
'in'+'sure'+'r'='INSURER'
'at' is the link.
(Other definitions for insurer that I've seen before include "one will provide cover" , "Company offering protection" , "One offering cover" , "One paying out in event of damage" , "Is rerun (anag)" .)