In terms of Section 7 read with Schedule I, following would qualify as supply:
1. Supply of goods by a principal to his agent where the agent undertakes to supply such goods on behalf of the principal; or
2. Supply of goods by an agent to his principal where the agent undertakes to receive such goods on behalf of the principal.
(ICAI FAQ PUBLICATIONS 06-09-2017 SCOPE OF SUPPLY : FAQ NO. 7)