shard0

shard0 is a high-performance Rust utility designed to solve a specific scaling bottleneck in the Discord API: the Shard 0 DM concentration. In the Discord gateway architecture, all Direct Messages (DMs) are routed exclusively to Shard 0. For large-scale bots, this single shard often becomes a performance bottleneck while other shards remain underutilized.

This project introduces a subsharding layer that intercepts Shard 0 traffic and redistributes it across multiple proxy instances based on DM channel IDs. This allows developers to scale DM processing horizontally without changing their bot's core logic.

Configuration

shard0

Variable	Description
DISCORD_TOKEN	discord bot token
TOTAL_SHARDS	total shards the discord bot has (default: 2)
REDIS_URL	redis connection url (default: redis://127.0.0.1/)
TOTAL_SUBSHARDS	total number of subshards created (default: 4)

shard0-proxy

Variable	Description
SUBSHARD	the subshard it should connect to
PORT	port the proxy listens at (default: 4343)
REDIS_URL	redis connection url (default: redis://127.0.0.1/)

How to use

discord.py

# import statements

WS_URL = "ws://127.0.0.1:4343"

get_bot_gateway = discord.http.HTTPClient.get_bot_gateway

async def custom_get_bot_gateway(self, *args, **kwargs):
    data = await get_bot_gateway(self, *args, **kwargs)
    data['url'] = WS_URL
    return data

discord.http.HTTPClient.get_bot_gateway = custom_get_bot_gateway

# rest of your code, e.g.:

bot = commands.Bot(command_prefix="!")

discord.js

const { Client } = require('discord.js');

const WS_URL = "ws://127.0.0.1:4343"

const client = new Client({
    // stuff
});

client.rest.get = new Proxy(client.rest.get, {
    apply(target, thisArg, args) {
        if (typeof args[0] === 'string' && args[0].includes('gateway')) {
            return Promise.resolve({
                url: WS_URL,
                shards: 1,
                session_start_limit: { total: 1000, remaining: 999, reset_after: 14400000, max_concurrency: 1 },
            });
        }
        return Reflect.apply(target, thisArg, args);
    }
});