How to add AI to Foundry VTT.

What you need

• Foundry VTT v13 or later, and a world you run as GM. Your players install nothing to sit at your table; a Familiar of their own is optional, on a key or an AI app they bring.
• The Familiar module, installed and enabled. The click path is next.
• A Familiar licence: a subscription with the first two weeks free, or the one-time lifetime purchase. The key is in your customer portal, not the receipt: the Access purchase link in that email opens it, and so does familiarvtt.com/account. It starts with FAMILIAR- and switches the module on.
• A published adventure to import, so the AI has maps, NPCs and statblocks to run from. D&D 5e (2024) also gets the rules engine; on other Foundry systems everything else still runs, and your own system keeps the rules.
• An AI: a provider key, or an AI account you already hold. Both ways in are compared below.

• Not playing D&D 5e?Which systems have a page of their own, before you pick what to import.

Install and activate Familiar

Familiar installs like any other module, and nothing here needs a terminal. This is the licence-key step; the provider key comes later.

Two Foundry modules share the name Familiar. Ours is the one by Ryan Jansen, the familiar-vtt package on npm. The other is an unrelated module last updated in 2024, and its documentation does not describe this one.

1. 1

   Install the module

   In Foundry, open Add-on Modules, click Install Module, search Familiar and click Install. Or paste the manifest URL below into the same dialog.

2. 2

   Enable Familiar in your world

   Tick it in the world you run, and save. The world reloads, and with no key stored the chat opens by itself on the activation card.

3. 3

   Paste your licence key and click Activate

   The key goes on that card, never in Foundry's own settings sheet. The page reloads and the chat closes with it. The owl button brings it back, and so does Ctrl+Shift+Space.

https://github.com/Ryanjansen92/familiar-releases/releases/latest/download/module.json

• The install pageThe three routes in and the compatibility table, then connecting your AI on the same page.

Connect your AI: two doors

Familiar brings no model of its own: you point it at an AI you control, through one of two doors. The built-in chat takes a provider key. The MCP door is the one for a chat subscription you already hold.

• MCP vs API: which to chooseThe per-session numbers behind the middle row.

What each thing at the table needs

The plan or the key you just chose drives the AI, and that is all it drives. A Claude plan on its own runs the game and says nothing out loud. Everything the table hears or sees bills a key of its own, on either door, at that provider and nowhere else.

• Voices, transcription, music: the keys and the switchesEvery provider by name, what each one can do, and the three on-or-wait switches.
• Images and battlemaps: the keys and the settingsWhich image provider does what, and the settings behind a generated map.

Door one: paste an API key

With the module activated, paste a provider key and the first reply lands in about a minute. The campaign comes later, with the adventure you import.

Demo clip coming

1. 1

   Open Familiar's settings

   The owl button sits at the bottom left until you drag it elsewhere. It opens the chat, whose Configure AI Provider button lands on the Chat tab. Or Module Settings, Familiar, Configure AI.

2. 2

   Pick a provider and paste the key

   OpenRouter is already selected, and one key there reaches most models. The Model row starts on Provider default, so a first reply needs no pick. There is no Save button: the key is saved once you leave the field, press Enter or close the window, and a small Saved flashes. Keys stay in your browser and go straight to the provider.

3. 3

   Close the settings and say something

   The chat opens on a row of suggestion chips: How it works, Rules, Monster, Encounter, NPC. Clicking one sends it, or type your own line.

• Which model, and how hard it should thinkLeave the default alone for a first session. This is what to change after.
• A model on your own machineThe Local / Custom tab, and the route with no token bill at all.

Door two: the plan you already pay for

Module Settings, Familiar, Configure AI, then the MCP / Subs tab. Pick your client's card: it carries this world's secret already filled in.

The first start downloads Familiar's server, so give it a minute.

Demo clip coming

• Three ways through the setupFollow the card, let any AI chat walk you through it, or on some cards let the app register Familiar as you approve; plus the fixes every client shares.

Check it answers from your world

How you know it worked depends on the door. In the built-in chat, the reply names your world back to you. Over MCP the wizard closes on its own verify line, and the status rows on that tab turn to Connected.

Each ask below leans on something your world already holds.

• Combat & Initiative
• Journals & Notes
• Audio & Playlists
• Scenes & Tokens

• The first ask

  Which world is this, and which scene is active?

  Copy The first ask
• Over MCP, the wizard's line

  Use Familiar's get-world-info tool

  Copy Over MCP, the wizard's line
• Start a fight

  Start combat with every token on this scene.

  Copy Start a fight
• Read your own notes

  Search my journals for <NPC or place> and read me the entry.

  Copy Read your own notes
• Set the mood

  Play <playlist name> and darken the scene for night.

  Copy Set the mood

• Everything it can doThe rest of what those lines reach for, laid out by domain.

What it runs, and what stays yours

Familiar (familiar-vtt) is an AI co-pilot for Foundry VTT, licensed through familiarvtt.com. You talk to it in plain language and it does the work a GM would otherwise do by hand: it rolls initiative, runs the monsters, looks up a rule, voices an NPC, keeps a record of the campaign.

Ask an AI to invent a campaign from nothing and it drifts. Give it a full published adventure and it runs the table on that, from a single scene to an entire campaign. The fewer humans at the table, the more it runs.

Someone hand-painted the map in that adventure and placed every wall and light on it; Familiar runs on that work rather than redrawing it. It keeps no secrets either: hidden information is Foundry's own fog of war, not an AI choosing what to withhold.

• How to play D&D with AIThe method on top of this: what you bring, and what you hand over.
• Prepping a published adventureGetting the module in, so these asks have real pages to answer from.
• Playing solo and duetWhat changes when you are the only human at the table.