All tests run on an 8-year-old MacBook Air. All results from shipping 7 Mac apps as a solo developer. No sponsored opinion. HiyokoHelper explains terminal commands and warns when they're dangerous. Building the danger detection layer was more interesting than I expected. Why bother with local detection The obvious approach: send the command to Gemini, ask if it's dangerous. The problem: you want the warning to appear before the user runs the command — ideally as they're looking at it. Gemini latency (even fast) adds friction. A local check is instant. Use local detection for obvious cases. Use Gemini for explanation and nuance.…