go-chat

Small anonymous WebSocket chat backend in Go.

Architecture

• cmd/server wires configuration, logging, HTTP routing, websocket transport, and shutdown.
• internal/config owns environment parsing and runtime defaults.
• internal/chat owns message validation, event creation, and the concurrency-safe room abstraction.
• internal/transport/http owns HTTP routes, health checks, static compatibility serving, and security headers.
• internal/transport/websocket owns Gorilla websocket upgrade, deadlines, origin checks, client queues, and JSON IO.

The backend no longer depends on Gin. It uses the standard net/http server plus Gorilla WebSocket, which keeps the runtime small and makes transport concerns explicit.

Run

go run ./cmd/server

The default HTTP address is :8080.

Configuration

Configuration is provided through environment variables. See .env.example for supported values.

Important websocket controls:

• WS_ALLOWED_ORIGINS: comma-separated explicit origin allow-list. If empty, same-host and loopback origins are allowed.
• WS_READ_LIMIT_BYTES: maximum inbound websocket message size.
• WS_SEND_QUEUE_SIZE: per-client outbound queue size. Slow clients are disconnected instead of blocking the room.

Checks

go test ./...
go vet ./...