A method for using a needle-tip shielding mechanism, the method comprising: providing a needle-tip shielding mechanism, comprising: an outer housing having an adapter-interlock feature and a proximal opening; an inner housing comprising a needle-feature capture mechanism and a needle-tip capture mechanism, wherein the needle-tip capture mechanism comprises a duckbilled tip barrier having two flaps extending proximally into the inner housing, wherein the inner housing is slidably movable within the outer housing between a first position that biases the adapter-interlock feature into an engaged position and a second position that allows the adapter-interlock feature to move to an unengaged position; and a needle that extends into the inner housing, the needle having a needle feature and a tip, wherein the two flaps are configured to bias against each other in a manner that blocks the tip of the needle; and a needle hub coupled to the needle, wherein the needle or the needle hub includes a protuberant feature; and pushing the needle distally such that the protuberant feature passes through the proximal opening of the outer housing, contact the inner housing, and moves the inner housing to the first position. providing a needle-tip shielding mechanism, comprising: an outer housing having an adapter-interlock feature and a proximal opening; an inner housing comprising a needle-feature capture mechanism and a needle-tip capture mechanism, wherein the needle-tip capture mechanism comprises a duckbilled tip barrier having two flaps extending proximally into the inner housing, wherein the inner housing is slidably movable within the outer housing between a first position that biases the adapter-interlock feature into an engaged position and a second position that allows the adapter-interlock feature to move to an unengaged position; and a needle that extends into the inner housing, the needle having a needle feature and a tip, wherein the two flaps are configured to bias against each other in a manner that blocks the tip of the needle; and a needle hub coupled to the needle, wherein the needle or the needle hub includes a protuberant feature; and an outer housing having an adapter-interlock feature and a proximal opening; an inner housing comprising a needle-feature capture mechanism and a needle-tip capture mechanism, wherein the needle-tip capture mechanism comprises a duckbilled tip barrier having two flaps extending proximally into the inner housing, wherein the inner housing is slidably movable within the outer housing between a first position that biases the adapter-interlock feature into an engaged position and a second position that allows the adapter-interlock feature to move to an unengaged position; and a needle that extends into the inner housing, the needle having a needle feature and a tip, wherein the two flaps are configured to bias against each other in a manner that blocks the tip of the needle; and a needle hub coupled to the needle, wherein the needle or the needle hub includes a protuberant feature; and pushing the needle distally such that the protuberant feature passes through the proximal opening of the outer housing, contact the inner housing, and moves the inner housing to the first position.