Subi.ai Information

Subi was a general-purpose AI executive assistant, reachable by chat, voice, and phone. It began as Agents4All, built on the same timeline as OpenAI's GPT Store and Poe, which were both assembling marketplaces of specialized bots at the end of 2023. Customer feedback taught us that making people choose a specialized agent was a point of friction. We refocused on a single general agent that selected its own tools and few-shot examples based on semantic relevance to the task and on past performance in practice. That became Subi. Incubated at Idealab, Subi paired a multi-agent runtime with 60+ integrated tools spanning email, calendar, web search, and a sandboxed code-execution environment. For each task the system assembled a team on the fly, a supervisor plus the specialist roles the work required. Ambient listening over streaming calendar and email events let the assistant act proactively rather than only when asked. The team pioneered techniques in agentic harness and memory systems, reflection loops, sandbox-based RL environments, and tool generation with self-evaluation. Releases were gated by a blind LLM-judge trajectory evaluation over a task benchmark, and a self-improving practice loop let a smaller, cheaper model approach frontier-model performance on solutions discovered in practice. That work produced provisional patents covering LLM self-improvement (RLHF with AI reflection), auto-sourcing task execution, and audio-agent optimization. Founded in 2023 by David Zito and Alex Bernier. Acquired by ProRata.ai in February 2025, including the team, IP, and patents. The subi.ai product is no longer operating.