Y Combinator Open-Sources QM Multiplayer Agent Harness

Y Combinator has released QM (quartermaster) as open-source software under the MIT license, a multiplayer agent harness deployed internally across accounting, legal, events, and engineering teams. Unlike single-user assistants, QM provides each employee with isolated workspaces containing scoped memory, file storage, permissions, and scheduled tasks, enabling collaborative agent-based workflows in Slack and web environments. The system maintains model-agnostic architecture, supporting Claude, Pi, OpenCode, and Codex through a shared core infrastructure. Deployment requires cloud infrastructure with Postgres, targeting startups and mid-sized companies with 10 to 500 employees having dedicated platform engineering resources. YC frames the release as an early-stage experiment with acknowledged bugs.