Wireless communications systems and methods related to transmitting sidelink channel state information (CSI) from one user equipment (UE) to another UE using a L1 signal. A first UE requests a CSI report from a second UE. The first UE sends a reference signal which the second UE measures to determine channel characteristics. The second UE forms a CSI report which includes a rank indicator, a channel quality indicator, and potentially a precoding matrix index indicator. The second UE forms the CSI report at the PHY level. The CSI report is included in reserved field(s) of a second stage sidelink control information (SCI-2). The first UE receives and processes the CSI report at a PHY level.