Discard

Discard is a self-hosted chat application for private friend groups on Tailscale. A single Go server provides the API, WebSocket text chat, WebRTC voice and screen sharing, and the built Svelte frontend; PostgreSQL stores application data.

Stack

Component	Technology
Backend	Go 1.27, pgx, Gorilla WebSocket
Frontend	SvelteKit 2, Svelte 5, TypeScript, Vite 8
Database	PostgreSQL 17
Voice and screen sharing	Pion WebRTC with embedded TURN fallback
Authentication	Tailscale identity, with a development-only bypass
Deployment	Single binary, Docker, or Docker Compose

Requirements

• Go 1.27
• Node.js 24.19 or newer and npm 11
• PostgreSQL 17
• ffmpeg, yt-dlp, and cwebp for media processing
• Tailscale for normal authentication and private-network access

Development

Create a PostgreSQL database and start the backend:

export DATABASE_URL='postgres://localhost:5432/discard?sslmode=disable'
export DISCARD_DEV=true
go run ./cmd/discard

In another terminal, install the frontend dependencies and start Vite:

cd web
npm ci
npm run dev

Open https://localhost:5173. Development mode exposes fixed test identities through ?dev_user=0 to ?dev_user=3; never enable DISCARD_DEV in production.

Testing

go test -race ./...
go vet ./...
cd web
npm ci
npm run check
npm run build

The Playwright suite requires PostgreSQL, the backend on port 4000, and the Vite HTTPS server on port 5173:

cd web
npx playwright install chromium
npm run test:e2e

The browser suite verifies bidirectional audio over both direct ICE and forced TURN relay connections.

Docker Compose

Set the required secrets in an ignored .env file:

TS_AUTHKEY=tskey-auth-...
TURN_SECRET=replace-with-a-random-secret

Then start the Tailscale sidecar, application, and PostgreSQL:

docker compose up -d --build

Compose stores PostgreSQL data, uploads, and Tailscale state in named volumes. It does not publish the application on the host network; access is through the Tailscale node and tailscale serve.

Configuration

Variable	Default	Purpose
PORT	4000	Backend HTTP port
DATABASE_URL	postgres://localhost:5432/discard?sslmode=disable	PostgreSQL connection string
UPLOAD_DIR	./uploads	Uploaded-file directory
DISCARD_DEV	false	Disable Tailscale authentication and expose fixed development users
DISCARD_PRODUCTION	false	Prevent accidental use of development authentication in production
TAILSCALE_API_URL	Local Tailscale API	Override the identity API endpoint
TAILSCALE_API_TOKEN	Unset	Authenticate to the macOS Tailscale local API
TURN_SECRET	Random per startup	Shared secret used for ephemeral TURN credentials
TURN_PUBLIC_IP	Auto-detected tailnet IP	Override the client-reachable TURN relay address
TURN_PORT	3478	Embedded UDP TURN listener port
API_TARGET	http://localhost:4000	Vite development proxy target

Set a persistent TURN_SECRET in deployed environments. Set TURN_PUBLIC_IP when automatic tailnet-address discovery is not suitable.

Blocking Behavior

• Blocking prevents direct-message creation, sending, and editing in both directions.
• Existing direct-message history remains available, and either participant may delete their own messages.
• Presence is hidden in both directions.
• Shared-server messages remain visible. Only the blocker sees the blocked author's name and avatar anonymized.
• Unblocking restores direct-message sending without deleting or recreating the conversation.

Production Build

make build

The frontend output is copied to internal/frontend/build for embedding in the production Go binary. The Dockerfile performs this process in reproducible build stages.