Latviankafija seems unlikely as a mediator (unless the addition of-ija (as popularized byJuris Alunāns) is a more recent development, Karulis doesn't listkafija) thus possibly directly fromGermanKaffee.
2012–2013, “kaffe”, in Tiit-Rein Viitso, Valts Ernštreits, editors,Līvõkīel-ēstikīel-lețkīel sõnārōntõz [Livonian-Estonian-Latvian Dictionary][1], Tartu, Riga: Tartu Ülikool, Latviešu valodas aģentūra:
Tiit-Rein Viitso; Valts Ernštreits (2012–2013), “kaffe”, inLīvõkīel-ēstikīel-lețkīel sõnārōntõz [Livonian-Estonian-Latvian Dictionary][2] (in Estonian and Latvian), Tartu, Rīga: Tartu Ülikool, Latviešu valodas aģentūra