Y Combinator open-sources its internal multi-agent Slack harness

Y Combinator released QM, an MIT-licensed "multiplayer agent harness" it built for internal use across accounting, legal, events, and engineering. Each Slack room gets its own scoped memory, files, permissions, and sandbox, and the same headless core can be driven by Pi, OpenCode, Codex, or Claude Code. It was open-sourced on July 31, 2026.

Why it matters: A backend-agnostic harness like this lets teams swap model providers without rebuilding their orchestration layer, reducing vendor lock-in for internal AI tooling. Coming from YC itself, it's also a signal of how startups are standardizing on Slack-native, multi-agent workflows instead of building bespoke internal tools from scratch.