Configuration Reference

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Backend Configuration

Environment Variables

Variable	Default	Description
PORT	8080	HTTP/WebSocket server listening port

Built-in Constants

The following parameters are defined in code and require recompilation to modify:

Parameter	Value	File	Description
MaxMembers	50	internal/room/room.go	Maximum members per room
writeWait	10s	internal/network/client.go	WebSocket write timeout
pongWait	40s	internal/network/client.go	Read timeout (1.5× heartbeat)
sendBufferSize	256	internal/network/client.go	Send buffer size
maxMessageSize	102400 bytes	internal/network/client.go	Maximum bytes per message (includes file chunks)
rateLimitWindow	10s	internal/network/client.go	Rate limit sliding window
rateLimitMaxCount	10	internal/network/client.go	Maximum messages per window
Ping interval	25s	internal/network/client.go	Heartbeat send interval
NanoID length	21 chars	internal/network/hub.go	Room ID length

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Frontend Configuration

Environment Variables

Variable	Default	File	Description
VITE_WS_URL	ws://localhost:8080/ws	.env.development	WebSocket server address

Environment Files

• .env.development — Development environment configuration
• .env.production — Production environment configuration (must be created)

Production example .env.production:

VITE_WS_URL=wss://your-backend-domain.com/ws

Built-in Constants

Parameter	Value	File	Description
MAX_MESSAGES	200	stores/chatStore.ts	Maximum messages retained in list
RATE_LIMIT_WINDOW_MS	10000	stores/chatStore.ts	Client-side rate limit window
RATE_LIMIT_MAX	10	stores/chatStore.ts	Maximum sends per window
TYPING_TIMEOUT_MS	2000	stores/chatStore.ts	Typing status auto-cancel time
MAX_LENGTH	500	components/MessageInput.tsx	Maximum characters per message
SHOW_COUNT_THRESHOLD	400	components/MessageInput.tsx	Threshold to show character count
BACKOFF_INITIAL_MS	1000	network/websocket.ts	Reconnection initial backoff time
BACKOFF_MAX_MS	30000	network/websocket.ts	Reconnection maximum backoff time

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Vite Configuration

File: arthas-client/vite.config.ts

import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [react()],
})

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CLI Client Configuration

Command-Line Arguments

Argument	Default	Description
--server	wss://arthas-chat.onrender.com/ws	WebSocket server URL
--name	Interactive prompt	Display nickname (1-20 characters)
--version	—	Show version and exit
--help	—	Show help information and exit

Environment Variables

Variable	Default	Description
ARTHAS_SERVER	—	WebSocket server URL (lower priority than --server flag)

Built-in Constants

Parameter	Value	File	Description
joinTimeout	30s	internal/chat/session.go	Timeout waiting for server response
writeWait	10s	internal/network/websocket.go	WebSocket write timeout
pongWait	40s	internal/network/websocket.go	Read timeout (1.6× heartbeat)
maxMessageSize	102400	internal/network/websocket.go	Maximum bytes per message
sendChCapacity	16	internal/network/websocket.go	Send queue capacity
Nickname length limit	20 runes	internal/ui/input.go	Maximum display name length
Message length limit	500 runes	internal/ui/input.go	Maximum message length

Configuration Priority

--server flag  >  ARTHAS_SERVER environment variable  >  default (wss://arthas-chat.onrender.com/ws)
--name flag    >  interactive prompt input

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Tailwind Configuration

File: arthas-client/tailwind.config.js

Uses dark theme by default, scans all TSX/TS files under src/.

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Docker Configuration

File: arthas-server/Dockerfile

Parameter	Value	Description
Base image	golang:1.23-alpine	Build stage
Runtime image	alpine:3.23	Minimal runtime environment
Exposed port	7860	Docker default port
PORT environment variable	7860	Server listening port

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Encryption Parameters

Parameter	Value	Description
Algorithm	AES-256-GCM	AEAD authenticated encryption
Key length	256 bits (32 bytes)	AES-256
IV length	96 bits (12 bytes)	GCM recommended length
roomId length	21 chars	NanoID default length
Share code format	{roomId}:{base64url(key)}	Total 65 characters
Share code length	65 chars	21 + 1 + 43

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Error Codes

Code	Name	Trigger Condition	Client Message
E001	ROOM_NOT_FOUND	roomId does not exist during JoinRoom	”Room does not exist or has been closed”
E002	ROOM_FULL	Room is full (50 members) during JoinRoom	”Room is full, cannot join”
E003	NOT_IN_ROOM	SendMessage/Typing without joining a room	”Please join a room first”
E004	RATE_LIMITED	Message rate exceeds 10 messages/10 seconds	”Sending too fast, please try again later”
E005	INVALID_MESSAGE	Invalid message format (empty/too long)	“Invalid message format”

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Next Steps

• Protocol Specification — Detailed message format definitions
• Self-Hosting Guide — Production environment deployment