Can we travel using the 144 hour visa free transit

We are due to arrive in Beijing from a cruise ship on 26th April. Our flight home is at 00.40 hours on the 30 April. Return Flights and seats are confirmed. We have booked tours for forbidden City and Matianyu Great Wall. Travel agent said we may need entry permit, but Chinese Center suggested we my be ok to obtain the 144 hour free transit.