What Plus One is Plus One is the hosted product that Every built by turning its internal experiment into something others can use. In the company's own telling, every employee ran a personal AI agent — one that took on its owner's personality, sent email, did computer errands, and even taught other agents skills in a dedicated Slack channel. Plus One is that setup, packaged and offered externally as a product. [^f575019b@0] Why it exists Running agents org-wide surfaced real lessons — agents inherit their owners' tone, working in public builds trust, and there are sharp failure modes around memory, group-chat pile-ups, and runaway loops. Those tradeoffs in product design are what shaped Plus One; understanding them is key to understanding the product. [^f575019b@0] <KeyPoint>Plus One is Every's hosted product version of its internal all-employees-get-an-agent experiment.</KeyPoint><KeyPoint>It grew directly out of observed design tradeoffs and failure modes, not theory.</KeyPoint><KeyPoint>Its lineage is Every's own agent culture: personal, personality-matched agents doing real work.</KeyPoint>