Methods, systems, and apparatus, including computer programs encoded on computer storage media, for providing content on a social messaging platform. One of the methods includes providing a plurality of messages of a social messaging platform to a user device, the plurality of messages being part of a conversation; receiving a request associated with one of the plurality of messages, the request including an indication to repost a collection of messages; providing a selection user interface, the selection user interface including the plurality of messages and a respective selection indicator for each message; receiving a user selection of two or more messages; responsive to the user selection, generating a message composition interface, the message composition interface including a representation of the selected messages; and in response to user input, posting the representation of the selected messages as part of a new message of the user on the platform.