Bethesda has officially announced that Fallout 4 Mods will be coming to PS4 as part of un an upcoming 1.8 Update. Although, not much information has been released about how the mods would work, their size is expected to be limited to 1GB and will not be able to use outside assets, so players can only create things like new dialogues and questlines.
Fallout 4 Mods will be available later this week on PS4 consoles as a free update sa part of the 1.8 Patch.