SDK

SDK Overview

The fnlb package is the self-hosted client. start() downloads the FNLB client, forks one process per shard, and logs those bots into Fortnite. Events, party meta, chat, and bot.runCommand talk to those processes over local IPC. fnlb.api is a separate HTTP client for the same account, including bots that are not running in this process. Install, tokens, shards, and shutdown stay on the Node.js SDK page. Every class and method is also in the SDK Reference. The machine-readable spec is /sdk.json. Generated Markdown for one symbol is under /sdk-reference, for example Party.

What you import

import FNLB, {
  Events,
  PartyPrivacy,
  Playlist,
  PresenceOnlineType,
  ApiError,
  SDK_BRIDGE_UNAVAILABLE
} from 'fnlb';

Export	Use it for
`FNLB`	The client. `start()`, `stop()`, `on`, `bots`, `api`. Reference: `FNLB`.
`Events`	Listener names. Reference: `Events`.
`PartyPrivacy`	`party.setPrivacy`. Reference: `PartyPrivacy`.
`Playlist`	Built-in playlist link ids for `party.setPlaylist`. Reference: `Playlist`.
`PresenceOnlineType`	`bot.setStatus`. Reference: `PresenceOnlineType`.
`ApiError`	Non-2xx responses from `fnlb.api`. Reference: `ApiError`.
`SDK_BRIDGE_UNAVAILABLE`	Thrown when a shard never opens the local bridge.

Bot, Party, PartyMember, PartyMeta, Message, and Collection are also exported if you want the types. You normally receive them from fnlb.on and fnlb.bots.

Two ways to talk to a bot

	Local shard	HTTP API
When	The bot is running in this process	Any bot on the account, online or not
Entry	`fnlb.bots`, `bot.party`, `fnlb.on`	`fnlb.api` after `start()`
Party meta	`bot.party.meta` and `bot.party.me.meta`	Not available. The API member route is a cosmetic snapshot.
Commands	`bot.runCommand`	`fnlb.api.bots.commands.run`
Chat	`bot.send`, `bot.whisper`, `message.reply`	`fnlb.api.bots.chat.send`
Friends	`bot.friends()`, `addFriend`, `block`	`api.bots.friends.list` reads a connected bot. It does not add or block.
Cosmetics	`party.setOutfit` and the other member methods	A command through `commands.run`, or a category config outfit list

Guides

Events
Ready, chat, friends, invites, joins, and cosmetic changes.
Bots and parties
Members, meta, privacy, playlists, and cosmetics.
Chat and commands
Party chat, whispers, friend requests, and local commands.
HTTP client
List bots, categories, presets, and run cloud commands.
Category config
Keys for overrideCategoryConfig and selection overrides.
Node.js SDK
Install, authenticate, shard, and stop the process.
SDK Reference
Generated classes, methods, and types.

A complete loop

import FNLB, { Events, PartyPrivacy, Playlist } from 'fnlb';

const fnlb = new FNLB({ clusterName: 'dev' });

fnlb.on(Events.Ready, (bot) => {
  console.log(bot.displayName, 'is ready');
});

fnlb.on(Events.PartyMemberMessage, async (message) => {
  if (message.content === '!ping') await message.reply('pong');
});

await fnlb.start({
  token: 'FNLB_...',
  categories: ['your-category-id']
});

const bot = await fnlb.bots.fetch('bot-id');
await bot.party.setPrivacy(PartyPrivacy.PRIVATE);
await bot.party.setPlaylist(Playlist.SQUAD);
await bot.party.setOutfit('CID_028_Athena_Commando_F');
await bot.party.meta.set('Default:CustomMatchKey_s', 'my-key');

const accountBots = await fnlb.api.bots.list();

fnlb.bots.cache only contains bots this process has started. fnlb.api.bots.list() is every bot on the token.

Shards

Each shard is a child process. fnlb.shards holds them after start(). fnlb.fetchShardInfo() returns version, protocol, gateway connection, and bot count for each one. fnlb.broadcast(method, params) sends one bridge call to every shard and returns a result per shard. A failed shard is ok: false and does not reject the whole call. Prefer fnlb.bots for party, chat, and commands. Use the shard when you want Shard.fetchInfo.

When a call throws

Error	Cause
`SDK_BRIDGE_UNAVAILABLE`	The shard never announced the bridge. The downloaded FNLB client is too old, or it exited before hello.
`Bot <id> is not running on this client.`	`fetch` was asked for a bot this process did not start. Use `fnlb.api.bots.get` for account bots.
`Only this bot can change its own member.`	`party.members.get(someoneElse).setOutfit` (or any other self-only member method).
Party leader errors from Fortnite	`setPrivacy`, `kick`, `setPlaylist`, and the other leader calls when this bot is not the leader.
`ApiError`	`fnlb.api` got a non-2xx response. `status`, `path`, and `body` are on the error.

Local party calls need a current FNLB client. An older build rejects fortnite.action with an unknown-method error. fnlb.api still works on that build.

Where to go next

You want to	Read
Hear ready, chat, invites, and cosmetic changes	Events
Change privacy, playlist, meta, or cosmetics	Bots and parties
Chat, friends, and `runCommand`	Chat and commands
Create bots, categories, or run a cloud command	HTTP client
Override dashboard settings for this run	Category config
Install, tokens, and shard counts	Node.js SDK