Codeword is at 917 Folsom Street, at 5th Street. Here's a map.

From the South Bay:
Via 280 North: take the 6th Street exit, then turn right on Folsom.
Via 101 North: take the 9th Street / Civic Center exit. Follow 9th Street, then turn right on Folsom.

From the East Bay:
From the Bay Bridge, take 80 West to the Harrison Street exit. Turn right on 6th, then right on Folsom.

By Public Transit:
The nearest BART station is Powell at 5th and Market, three blocks away. There is also a bus stop at 5th and Folsom, directly across the street.

Ample public parking is available at the 5th and Mission Garage, two blocks away. The garage is open 24/7. You can also find free street parking, but beware of the street cleaning signs.