Kapa signed Te Tiriti at Tauranga in April or May 1840, writing his own name. He was the son of Waikawa and the only rangatira from Ngāti Ranginui to sign the Treaty. In 1839 he signed the second deed of sale of Te Papa block to Alfred Brown and the Church Missionary Society.
For further information and sources see Debbie McCauley, The Treaty of Waitangi in Tauranga: Te Tiriti o Waitangi ki Tauranga Moana: https://debbiemccauleyauthor.wordpress.com/heritage/cultural-heritage/te-tiriti-o-waitangi-ki-tauranga-moana-treaty-signatories