Complete reference for Steam Apps/DLC functionality in Steamworks FFI.

The SteamAppsManager provides 28 functions covering DLC ownership, app verification, beta branches, and app metadata through the ISteamApps interface.

Functions for verifying app and DLC ownership status.

Checks if the user has access to the current app.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsSubscribed() - Check current app subscription

Returns: boolean - true if user owns or has access to the app

Example:

import SteamworksSDK from 'steamworks-ffi-node';

const steam = SteamworksSDK.getInstance();
steam.init({ appId: 480 });

if (steam.apps.isSubscribed()) {
  console.log('User has access to this app');
}

Notes:

• Returns true for owned games, free weekends, Family Sharing, etc.
• Use more specific methods to determine the type of access

Checks if the user owns a specific app.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsSubscribedApp() - Check specific app subscription

Parameters:

• appId: AppId - App ID to check ownership for

Returns: boolean - true if user owns the specified app

Example:

// Check if user owns the full game (for a demo)
const FULL_GAME_ID = 123456;
if (steam.apps.isSubscribedApp(FULL_GAME_ID)) {
  console.log('User owns the full game - hide purchase prompts');
}

Notes:

• Useful for checking if user owns related games (demos, sequels, etc.)
• For DLC, use isDlcInstalled() instead

Checks if an app is installed (regardless of ownership).

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsAppInstalled() - Check if app is installed

Parameters:

• appId: AppId - App ID to check

Returns: boolean - true if app is installed on this machine

Example:

if (steam.apps.isAppInstalled(480)) {
  console.log('Spacewar is installed');
}

Checks if running in low violence mode.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsLowViolence() - Check low violence mode

Returns: boolean - true if low violence mode is active

Notes:

• Some regions require reduced violence content
• Use this to swap assets or disable violent content

Checks if running on a cybercafe account.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsCybercafe() - Check cybercafe status

Returns: boolean - true if running on a cybercafe account

Checks if user has a VAC ban.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsVACBanned() - Check VAC ban status

Returns: boolean - true if user has a VAC ban

Checks if playing through a free weekend.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsSubscribedFromFreeWeekend() - Check free weekend access

Returns: boolean - true if user is playing via free weekend

Example:

if (steam.apps.isSubscribedFromFreeWeekend()) {
  showPurchasePrompt('Get 20% off during the free weekend!');
}

Notes:

• Use this to show purchase prompts to free weekend players
• Returns false for users with a retail or other license type

Checks if playing through Steam Family Sharing.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsSubscribedFromFamilySharing() - Check Family Sharing

Returns: boolean - true if user is borrowing via Family Sharing

Example:

if (steam.apps.isSubscribedFromFamilySharing()) {
  const ownerId = steam.apps.getAppOwner();
  console.log(`Playing via Family Sharing from ${ownerId}`);
}

Notes:

• If true, call getAppOwner() to get the lender's Steam ID
• Some games restrict features for borrowed copies

Gets comprehensive ownership information in one call.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsSubscribed() - Check subscription
• SteamAPI_ISteamApps_BIsSubscribedFromFreeWeekend() - Check free weekend
• SteamAPI_ISteamApps_BIsSubscribedFromFamilySharing() - Check Family Sharing
• SteamAPI_ISteamApps_BIsAppInstalled() - Check installation
• SteamAPI_ISteamApps_GetEarliestPurchaseUnixTime() - Get purchase time
• SteamAPI_ISteamApps_GetAppOwner() - Get owner Steam ID

Returns: AppOwnershipInfo

Type:

interface AppOwnershipInfo {
  isSubscribed: boolean;
  isSubscribedFromFreeWeekend: boolean;
  isSubscribedFromFamilySharing: boolean;
  isInstalled: boolean;
  earliestPurchaseTime: number;  // Unix timestamp
  ownerId: bigint;               // Steam ID of actual owner
}

Example:

const ownership = steam.apps.getOwnershipInfo();

console.log(`Subscribed: ${ownership.isSubscribed}`);
console.log(`Free Weekend: ${ownership.isSubscribedFromFreeWeekend}`);
console.log(`Family Sharing: ${ownership.isSubscribedFromFamilySharing}`);
console.log(`Owner: ${ownership.ownerId}`);

Functions for managing DLC content.

Checks if a DLC is owned AND installed.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsDlcInstalled() - Check DLC ownership and installation

Parameters:

• dlcAppId: AppId - App ID of the DLC

Returns: boolean - true if DLC is owned and installed

Example:

const EXPANSION_DLC = 123456;
const SOUNDTRACK_DLC = 123457;

if (steam.apps.isDlcInstalled(EXPANSION_DLC)) {
  enableExpansionContent();
}

if (steam.apps.isDlcInstalled(SOUNDTRACK_DLC)) {
  enableMusicPlayer();
}

Notes:

• Checks both ownership AND installation status
• For optional DLC, user may own but not have downloaded

Gets the number of DLC items for this app.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetDLCCount() - Get DLC count

Returns: number - Number of DLC items available

Example:

const dlcCount = steam.apps.getDLCCount();
console.log(`This game has ${dlcCount} DLC items`);

Gets data about a DLC by index.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BGetDLCDataByIndex() - Get DLC metadata by index

Parameters:

• index: number - DLC index (0 to getDLCCount()-1)

Returns: DLCData | null

Type:

interface DLCData {
  appId: AppId;       // DLC App ID
  available: boolean; // User owns this DLC
  name: string;       // Display name
}

Example:

const dlc = steam.apps.getDLCDataByIndex(0);
if (dlc) {
  console.log(`DLC: ${dlc.name} (${dlc.appId})`);
  console.log(`Available: ${dlc.available}`);
}

Gets all DLC data at once.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetDLCCount() - Get count
• SteamAPI_ISteamApps_BGetDLCDataByIndex() - Get each DLC

Returns: DLCData[] - Array of all DLC data

Example:

const allDlc = steam.apps.getAllDLC();

console.log(`This game has ${allDlc.length} DLC items:`);
allDlc.forEach(dlc => {
  const status = dlc.available ? '✓ Owned' : '✗ Not Owned';
  console.log(`  ${dlc.name}: ${status}`);
});

Triggers download/installation of optional DLC.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_InstallDLC() - Start DLC installation

Parameters:

• dlcAppId: AppId - App ID of the DLC to install

Returns: void

Example:

// User clicks "Download Expansion"
steam.apps.installDLC(EXPANSION_DLC);
showNotification('Expansion download started in Steam');

Notes:

• DLC must be owned by the user
• Download happens through Steam client
• Listen for DlcInstalled_t callback for completion

Removes optional DLC files from disk.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_UninstallDLC() - Remove DLC files

Parameters:

• dlcAppId: AppId - App ID of the DLC to remove

Returns: void

Example:

steam.apps.uninstallDLC(EXPANSION_DLC);
console.log('DLC removed to free up disk space');

Notes:

• User still owns the DLC
• Only removes local files to free disk space
• Can be reinstalled anytime with installDLC()

Gets download progress for a DLC.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetDlcDownloadProgress() - Get download progress

Parameters:

• dlcAppId: AppId - App ID of the DLC

Returns: DLCDownloadProgress | null

Type:

interface DLCDownloadProgress {
  bytesDownloaded: bigint;
  bytesTotal: bigint;
  percentComplete: number;  // 0-100
}

Example:

function updateDownloadUI(dlcId: number) {
  const progress = steam.apps.getDlcDownloadProgress(dlcId);
  if (progress) {
    progressBar.setValue(progress.percentComplete);
    console.log(`${progress.bytesDownloaded}/${progress.bytesTotal} bytes`);
  }
}

Notes:

• Returns null if DLC is not currently downloading

Sets the current DLC context for usage tracking.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_SetDlcContext() - Set DLC context for tracking

Parameters:

• dlcAppId: AppId - DLC App ID being played (0 to clear)

Returns: boolean - true if successful

Example:

// Player entered expansion content
steam.apps.setDlcContext(EXPANSION_DLC);

// Player returned to base game
steam.apps.setDlcContext(0);

Notes:

• Allows Steam to track usage of major DLC extensions
• Set to 0 when player leaves DLC content

Functions for retrieving app metadata.

Gets the current game language.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetCurrentGameLanguage() - Get current language

Returns: string - Language code (e.g., 'english', 'german', 'french')

Example:

const lang = steam.apps.getCurrentGameLanguage();
loadLocalization(`locales/${lang}.json`);

Notes:

• Returns the language the user has set for the game in Steam
• Common values: english, german, french, spanish, russian, etc.

Gets all available game languages.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetAvailableGameLanguages() - Get supported languages

Returns: string - Comma-separated list of language codes

Example:

const langs = steam.apps.getAvailableGameLanguages();
// "english,german,french,spanish,russian"
const langArray = langs.split(',');
console.log(`Supported languages: ${langArray.join(', ')}`);

Gets the Unix timestamp of the earliest purchase.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetEarliestPurchaseUnixTime() - Get purchase time

Parameters:

• appId: AppId - App ID (0 for current app)

Returns: number - Unix timestamp or 0 if not owned

Example:

const purchaseTime = steam.apps.getEarliestPurchaseUnixTime(0);
const date = new Date(purchaseTime * 1000);
console.log(`You've owned this game since ${date.toLocaleDateString()}`);

Gets the installation directory for an app.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetAppInstallDir() - Get install path

Parameters:

• appId: AppId - App ID to get path for

Returns: string - Full installation path or empty string

Example:

const installPath = steam.apps.getAppInstallDir(480);
// "/home/user/.steam/steam/steamapps/common/Spacewar"
console.log(`Installed at: ${installPath}`);

Gets the Steam ID of the app owner.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetAppOwner() - Get owner Steam ID

Returns: bigint - Steam ID (may differ from current user if Family Sharing)

Example:

const ownerId = steam.apps.getAppOwner();
if (steam.apps.isSubscribedFromFamilySharing()) {
  console.log(`Borrowed from: ${ownerId}`);
}

Gets the current build ID.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetAppBuildId() - Get build ID

Returns: number - Build ID (may change with backend updates)

Example:

const buildId = steam.apps.getAppBuildId();
console.log(`Running build: ${buildId}`);

Gets installed depot IDs for an app.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetInstalledDepots() - Get installed depots

Parameters:

• appId: AppId - App ID to check
• maxDepots: number - Maximum number of depots to return (default 32)

Returns: DepotId[] - Array of installed depot IDs in mount order

Example:

const depots = steam.apps.getInstalledDepots(480);
console.log(`Installed depots: ${depots.join(', ')}`);

Gets comprehensive build information.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetAppBuildId() - Get build ID
• SteamAPI_ISteamApps_GetCurrentBetaName() - Get beta name
• SteamAPI_ISteamApps_GetAppInstallDir() - Get install path

Returns: AppBuildInfo

Type:

interface AppBuildInfo {
  buildId: number;    // Current build ID
  betaName: string;   // Current beta branch ('public' if default)
  installDir: string; // Installation path
}

Example:

const info = steam.apps.getBuildInfo();
console.log(`Build: ${info.buildId}`);
console.log(`Beta: ${info.betaName}`);
console.log(`Path: ${info.installDir}`);

Functions for managing beta branches.

Gets the name of the current beta branch.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetCurrentBetaName() - Get current beta name

Returns: string - Beta name or 'public' if on default branch

Example:

const beta = steam.apps.getCurrentBetaName();
console.log(`Current beta: ${beta}`);

Gets counts of available beta branches.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetNumBetas() - Get beta counts

Returns: { total: number; available: number; private: number }

Example:

const betas = steam.apps.getNumBetas();
console.log(`Total: ${betas.total}`);
console.log(`Available: ${betas.available}`);
console.log(`Private: ${betas.private}`);

Gets information about a beta branch.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetBetaInfo() - Get beta details by index

Parameters:

• index: number - Beta index (0 to total-1)

Returns: BetaInfo | null

Type:

interface BetaInfo {
  name: string;
  description: string;
  buildId: number;
  flags: number;  // EBetaBranchFlags
}

Example:

const beta = steam.apps.getBetaInfo(0);
if (beta) {
  console.log(`${beta.name}: ${beta.description}`);
  console.log(`Build: ${beta.buildId}`);
}

Gets all beta branch information.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetNumBetas() - Get count
• SteamAPI_ISteamApps_GetBetaInfo() - Get each beta

Returns: BetaInfo[] - Array of all beta info

Example:

const betas = steam.apps.getAllBetas();
betas.forEach(beta => {
  console.log(`${beta.name}: ${beta.description}`);
});

Switches to a different beta branch.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_SetActiveBeta() - Set active beta

Parameters:

• betaName: string - Name of the beta to activate

Returns: boolean - true if successful

Example:

const success = steam.apps.setActiveBeta('experimental');
if (success) {
  console.log('Please restart the game to apply beta');
}

Notes:

• May require game restart for Steam to update files

Functions for accessing Steam URL launch parameters.

Gets a specific launch query parameter.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetLaunchQueryParam() - Get query parameter

Parameters:

• key: string - Parameter name to retrieve

Returns: string - Parameter value or empty string

Example:

// Game launched via steam://run/480//?server=192.168.1.1&port=27015
const server = steam.apps.getLaunchQueryParam('server');
const port = steam.apps.getLaunchQueryParam('port');
connectToServer(server, parseInt(port));

Notes:

• Launched via: steam://run/<appid>//?param1=value1&param2=value2
• Parameter names starting with '@' are reserved for internal use
• Parameter names starting with '_' are reserved for Steam features

Gets the full launch command line.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_GetLaunchCommandLine() - Get command line

Returns: string - Command line string or empty string

Example:

const cmdLine = steam.apps.getLaunchCommandLine();
console.log(`Launch command: ${cmdLine}`);

Notes:

• Launched via: steam://run/<appid>//<command line>
• More secure than OS command line
• Used for rich presence joins

Functions for checking timed trial status.

Checks if running as a timed trial.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_BIsTimedTrial() - Check timed trial status

Returns: TimedTrialStatus | null

Type:

interface TimedTrialStatus {
  isTimedTrial: boolean;
  secondsAllowed: number;
  secondsPlayed: number;
  secondsRemaining: number;
}

Example:

const trial = steam.apps.getTimedTrialStatus();
if (trial?.isTimedTrial) {
  const minutes = Math.floor(trial.secondsRemaining / 60);
  showTrialBanner(`${minutes} minutes remaining in trial`);
}

Signals Steam to verify game files.

Steamworks SDK Functions:

• SteamAPI_ISteamApps_MarkContentCorrupt() - Mark content for verification

Parameters:

• missingFilesOnly: boolean - If true, only check for missing files (default false)

Returns: boolean - true if request accepted

Example:

// Game detected corrupted save file
if (detectCorruption()) {
  steam.apps.markContentCorrupt(false);
  showError('Game files may be corrupted. Please verify via Steam.');
}

Notes:

• Signals Steam to verify game files on next restart
• Use missingFilesOnly=true for faster verification

import SteamworksSDK from 'steamworks-ffi-node';

const steam = SteamworksSDK.getInstance();
steam.init({ appId: 480 });

// Define DLC App IDs
const DLC = {
  EXPANSION: 480001,
  SOUNDTRACK: 480002,
  ARTBOOK: 480003
};

// Check all DLC
function checkDLCStatus() {
  const allDlc = steam.apps.getAllDLC();
  
  console.log('DLC Status:');
  allDlc.forEach(dlc => {
    const installed = steam.apps.isDlcInstalled(dlc.appId);
    console.log(`  ${dlc.name}: ${installed ? 'Ready' : 'Not Installed'}`);
  });
}

// Enable features based on ownership
function initializeFeatures() {
  if (steam.apps.isDlcInstalled(DLC.EXPANSION)) {
    enableExpansionMaps();
    enableExpansionCharacters();
  }
  
  if (steam.apps.isDlcInstalled(DLC.SOUNDTRACK)) {
    enableMusicPlayer();
  }
}

// Handle free weekend players
function checkAccessType() {
  if (steam.apps.isSubscribedFromFreeWeekend()) {
    showBanner('Free Weekend! Get 20% off the full game!');
    showPurchaseButton();
  }
  
  if (steam.apps.isSubscribedFromFamilySharing()) {
    // Some games restrict features for borrowed copies
    disableMultiplayerRanked();
  }
}

// Localization
function setupLocalization() {
  const lang = steam.apps.getCurrentGameLanguage();
  loadLanguage(lang);
}

// Run setup
checkDLCStatus();
initializeFeatures();
checkAccessType();
setupLocalization();

// Cleanup
steam.shutdown();

• Steam Apps Documentation
• DLC Best Practices
• Workshop Manager
• Cloud Manager