Headless React chat widget with a full-stack backend

What it does Cossistant is an open-source chat support widget built for React and Next.js applications. It ships headless UI primitives and hooks via @cossistant/react and @cossistant/next, backed by a complete real-time backend—WebSockets, Postgres, Redis, and a Hono API—so you aren’t left duct-taping a frontend SDK to your own servers.

The interesting bit Most open-source chat widgets are frontend-only; this one arrives as a full-stack monorepo with Docker, tRPC, and Drizzle ORM already wired up. The catch is the licensing split: AGPL-3.0 for non-commercial use, with a commercial license required if you actually ship it in a paid product.

Key highlights

• Headless React and Next.js SDKs with hooks and primitives
• Full backend stack included: Hono API, tRPC, Drizzle ORM, WebSockets, Dockerized Postgres and Redis
• Monorepo tooling via Turborepo and Bun
• AGPL-3.0 for non-commercial use; commercial deployments require contacting the author
• Part of the Vercel Open Source Program

Caveats

• The repository description promises AI support agents, but the README only cites “AI-friendly documentation”—how the agent features work is unclear
• Commercial use requires contacting the author for a separate license, so the AGPL-3.0 terms are not the whole story

Verdict Worth a look if you’re a React shop that wants to self-host support chat and keep data in-house. Skip it if you need a fully managed SaaS or a permissive license for commercial deployment without negotiation.