It is the latest part of the regeneration works ongoing at the quayside.
And Annan Harbour Action Group (AHAG) hope the shack will be up and running and serving hot drinks by the end of April.
The project has received National Lottery funding and support from Adapt and Thrive.
Facilities manager Alan Thomson said: “Even before we have the Harbour Hub facilities in place we wanted to provide something for the many people who come down to the harbour to watch the world going by.”
AHAG chair Richard Brodie added: “We are pleased to receive this National Lottery Community Fund award which will help us move forward our ambitious plans for Annan Harbour with the coffee shack providing an interface between ourselves and the community.
“We hope people will be able to comment on our plans over a nice cup of coffee.”
And National Lottery Community Fund, Scotland chair Kate Still said: “National Lottery funding can make amazing things happen in local communities across the country. This project delivered by Annan Harbour Action Group, is a great example of community activity in action, showing just what can be achieved when people come together for a common cause or to help others.”
Meanwhile, work is proceeding to raise the capital needed to transform the quayside warehouse into the hub.
It will host heritage exhibitions, provide workshops for community use, a training café, a bunkhouse and public meeting rooms.
The nearby Minister’s Merse, which is also now in community ownership, will be developed for boating, access to the river and public amenity.
