How to add AI to Foundry VTT.

What "AI in Foundry" actually means

Familiar is a Foundry module that puts an AI on the DM's side of the table. You talk to it in plain language and it does the work a GM would otherwise do by hand: rolls initiative, runs the monsters, looks up a rule, voices an NPC, keeps a record of the campaign. You stay in the scene instead of digging through menus.

Set the expectation honestly before you install anything. This is a co-pilot, not a replacement DM. It runs the published adventure you bring into Foundry: the maps, the NPCs, the statblocks, the journals you imported. It reads that and runs it. It is good at characterisation, bookkeeping, and recall when those sit on top of your prep. It is not an author. Ask an AI to invent an original campaign from nothing and it drifts. Familiar does not ask it to.

So "let an AI run your Foundry game" is honest, with one qualifier: the story is the one you imported, and the AI runs the table around it.

This is the line that separates Familiar from a weekend AI-DM app: it runs the adventure you imported, it does not improvise one.

The short version

Three steps, and the first one is the same as installing any Foundry module. The detail for each lives further down, but this is the whole shape of it.

1. 1

   Install Familiar

   Paste the Familiar manifest URL into Foundry and enable it in your world. This is the standard module install, no different from any other add-on. The click-by-click is below.

2. 2

   Connect the AI you already use

   Open Familiar's settings and connect a model. Two paths: use the Claude or ChatGPT subscription you already pay for, or paste an API key. Either way the keys are yours and the cost is yours.

3. 3

   Import an adventure and play

   Bring a published adventure into your world so the AI has journals, sheets, and statblocks to read. Then start a session and talk to your game.

Install the module

Familiar installs the way every Foundry module does. In Foundry, open Add-on Modules, click Install Module, and paste this manifest URL:

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

Click Install, then enable Familiar in the world where you run your game. That is the whole module setup. The site is the install route while the Foundry package listing is pending, so the manifest URL is the canonical way in. The home page has the same steps with a screenshot of the dialog.

Connect your AI: two paths

Familiar is bring-your-own-AI. It does not ship a model or proxy your tokens, so you point it at one you control. There are two ways to do that, and which you pick comes down to what you already pay for.

Most GMs already have one of these. If you pay for a Claude or ChatGPT plan, the MCP path puts that subscription to work with no extra API bill. If you would rather paste a key and start typing, the built-in chat path takes an API key from any of the supported providers and runs in the Foundry sidebar, with a few in-app conveniences like live transcription on top.

• Use your subscription (MCP). Connect through the Model Context Protocol so your existing Claude, ChatGPT, or Codex plan drives the game at no extra API cost. Best for long, multi-step turns. The step-by-step walkthrough is the "Connect via MCP" guide.
• Paste an API key (built-in chat). Pick a provider, paste a key, and talk to your game from Foundry's sidebar. No terminal, no config. The built-in chat also carries a few conveniences that live there only, like live transcription. Voice and image generation work on either path.

Not sure which path fits? The "MCP vs API" guide lays the two side by side: where the model runs, who you pay, and which features each one unlocks.

What it does once connected

With a model connected and an adventure imported, you run the game by talking to it. Say what you want and it happens, without breaking the scene to click through Foundry. These are shipped capabilities, mapped to what they actually do at the table.

• Combat bookkeeping. Roll initiative, resolve attacks and saves, apply conditions and damage, track death saves, and play the monsters' turns from their real statblocks, so a fight never stalls on the maths.
• Journal and rules lookup. Full-text search across every journal, character, scene, and item, so when a name or a 5e rule comes up the AI reads the actual entry instead of reaching for whatever sounds right.
• NPC voices. Anchor an NPC to a written character and the AI speaks them in their own assigned voice, holding to what their sheet says rather than improvising a new backstory.
• Prep support. The AI reads your imported journals and statblocks at the table, so the prep you built is what it runs from, not a guess.
• Cross-session memory. A persistent record of your campaign plus a rewritten plot summary carry from one session to the next, so what was true last week is still true tonight.

• Combat & AI
• Journals & Notes
• Voice & Image
• Knowledge & Memory

What stays yours, and what it will not do

Familiar runs the DM's side of the table: the rules, the dice, the monsters, the cast you wrote, and the recall. The story it tells is the one you imported. You hold the spine.

Two limits are worth stating plainly. It does not keep secrets from you: hidden information is Foundry's own fog of war and dice-gated reveals, not an AI deciding what to withhold. And it sits on the DM's side, running the world; it is not a party member fighting beside your character.

The trade is deliberate, and it is the honest one. You give it good prep and it gives you a table that runs itself around your story. The bookkeeping and the cast are reliable because they are anchored to what you built. The plot stays yours because that is the part an AI cannot be trusted to invent.

Add it to your next session

You do not need a full campaign prepped to start. Install Familiar in Foundry, connect the AI you already pay for, and import the first chapter of a published adventure you own. That is enough to run a session and see how it feels.

From there the two connect guides cover the setup in depth, and the prep guide covers how to lay an adventure out so the AI reads it cleanly. If you get stuck on a manifest install, an MCP config, or what to import first, the Discord is the place to ask.