  We show that a $3d$ sourced conformal Carrollian field theory has the right
kinematic properties to holographically describe gravity in $4d$ asymptotically
flat spacetime. The external sources encode the leaks of gravitational
radiation at null infinity. The Ward identities of this theory are shown to
reproduce those of the $2d$ celestial CFT after relating Carrollian to
celestial operators. This suggests a new set of interplays between gravity in
asymptotically flat spacetime, sourced conformal Carrollian field theory and
celestial CFT.
