A corporate social responsibility initiative by Federal Territories Ministry (DBKL) and MRCB, the 1,319-square metre centre was built at a cost of RM3 million.
The centre was set up after a surprise visit by Najib in July, 2014, to see for himself the condition of the homeless in the city.
Najib, who arrived at 11.30am, also mingled with the residents and checked on the conditions and facilities provided at the centre.
Also present were Federal Territories Minister Datuk Seri Tengku Adnan Tengku Mansor, National Welfare Foundation (YKN) chairman Datuk Seri Shahrizat Abdul Jalil, Malaysia Resources Corporation Bhd (MRCB) managing director Tan Sri Mohamad Salim Fateh Din and Titiwangsa member of Parliament Datuk Johari Abdul Ghani.
The prime minister also signed a plaque as a symbolic inauguration of the centre before being briefed on the operations by Federal Territories Ministry secretary-general Datuk Seri Adnan Md Ikshan.
The centre also received assistance from various parties, including a corporate body, Perbadanan Usahawan Nasional Berhad (PUNB), which contributed RM20,000 for the daily operating costs and an electronics company, Sharp Malaysia, which contributed various electrical products worth RM45,030.
To date, the centre has 141 occupants, who 125 of them are staying at the centre while the rest come on a daily basis to use the facilities and to get food.
The three-storey building, which could accommodate 250 people, has bathrooms, toilets as well as laundry, prayer, counselling, health and store rooms.
The transit centre is managed in two phases. The first phase, between February and June, will be operated by a temporary team from YKN, DBKL, Rela, Red Crescent Society and counsellors.
While the second phase involves the permanent administrative structure and the appointment of an organiser or chief operator through the request for proposal method.
Before this, the government had set up the Homeless Temporary Service Centre at Lorong Medan Tuanku 2, Jalan Sultan Ismail, which only provided toilets, bathrooms, prayer rooms as well as a food distribution point for homeless persons.