Like many other Front Street shops and restaurants, the cafe had been closed since the storm because of extensive damage to its building's electrical, heating and cooling systems.
"We're just so happy to be open," said Mark Mundorf, the store's manager. "It's amazing how many familiar faces we've already seen — we've had a lot of support from the community."
Mundorf said little had changed in the reconstructed shop, aside from the addition of vegan sweets, which are baked in another Jack's location.
The mini chain, which had been in the Seaport for about seven years before Sandy, has four other outposts.