Cactus

Cactus is a cross-platform, open-source AI inference engine built in C/C++ to run language, speech, and vision models directly on smartphones, laptops, wearables, and other low-power edge hardware. It gives mobile developers Flutter, React Native, Kotlin, and Swift SDKs to deploy quantized models on-device - cutting latency to under 100ms, keeping data private, working offline, and avoiding cloud API bills - with automatic cloud fallback for heavier tasks. A YC Summer 2025 company, Cactus already powers production apps serving 500,000+ weekly inference tasks.