OpenCity Harness is an open-source municipal AI harness. Type any city and show it a street image, and Gemma 4 evaluates disaster, grid, mobility and infrastructure risks in one multimodal call, combining the image with live weather, air quality and US weather alerts.

The dashboard shows four verdicts, a hazard zone on the map, recommended actions and a draft Open311 ticket. The worst finding is sent as one command byte to an Arduino UNO Q, which lights up its LED matrix.

Gemma scores each scene, while deterministic code validates the output, sets the status and picks the command. In 53 real Gemma calls, all 53 returned valid JSON on the first try. 41 of 42 test runs got the right response across six images, and all 10 clean-street runs stayed quiet. With the same clean photo, changing only the telemetry moved it from all clear to a disaster or grid warning.