`GetActiveCompanionDefId`

ESO Lua API function — used by 31 of the 3,030 addons we indexed (combined 5,262,228 downloads). Signature from the official ESOUIDocumentation.txt, API version 101050.

Official signature

GetActiveCompanionDefId()

Returns: integer activeCompanionDefId

Real usage — from Inventory Insight

  if HasActiveCompanion() then
    return ZO_CachedStrFormat(SI_UNIT_NAME, GetCompanionName(GetActiveCompanionDefId()))
    -- returns nil if no current active companion

Short excerpt from the shipping addon Inventory Insight — its ESOUI page; the code belongs to its author. Shown because documentation without a working example is half a reference.

Most-downloaded addons using it

Addon	Total downloads
Inventory Insight	2,763,446
WPamA (What Pledges at my Alts)	735,283
OdySupportIcons - Group Role Icons & More	484,590
Bar Steward - Multi Toolbar	204,140
Bandits Companions and Pets	192,393
SuperStar - Seasonal Update	178,124