Grimoire MCP · Your TTRPG bot

Your campaign, organized by magic.

One OAuth click and Claude, ChatGPT, or any AI assistant reads your world live. Canon facts, NPC motivations, faction politics, plot threads. No Node.js. No copy-paste. No bundled AI that lags the frontier.

Connect your campaign → See the 3-step setup

Free on Grimoire's free tier. Available with the free tier of Claude or ChatGPT. End-to-end free to try.

claude.ai grimoire connected

How would Queen Mira react if her brother betrayed her?

Grimoire MCP · reading your world

get_constitution get_entity get_knowledge_graph

Mira wouldn't rage. Her record shows she buries betrayal and waits. With Cyrus now in the Opposition, she'd move against House Vale first.

What is an AI assistant for D&D?

An AI assistant for D&D is a large language model (Claude, ChatGPT, Gemini, or similar) that helps a Dungeon Master with session prep, in-character dialogue, NPC reactions, rumor generation, and recall during play. The good ones answer in your campaign's canon; the bad ones hallucinate facts about your world. Grimoire MCP is the integration layer that turns your AI assistant of choice into one that respects your canon.

Build your own TTRPG bot.

Tool access from MCP. Canon events from your story. Paired with the frontier model of your choice. Make the Grimoire database the physics engine for your canon. Any homebrew quirk, any retconned event, any setting rule becomes a rule the AI can't bend. Connect Grimoire MCP and watch your AI become a living in-world expert in your unique setting and story.

Grimoire is built around the human DM. The AI helps you prep, recall, and draft between sessions. At the table, you keep the game. AI-assisted GMing means the AI never ships to your players without you seeing it first. The Dungeon Master is still you; the AI is just the assistant that remembers your campaign so you don't have to.

An AI assistant is only as good as the canon it can see. Most GMs feed their AI fragments and hope. Grimoire MCP feeds it the whole world.

Setup

Three clicks to connect

OAuth 2.1 with streamable HTTP. No installs, no terminal, no token pasting.

How does Grimoire MCP work with Claude?

Claude.ai and Claude Desktop both support MCP custom connectors on the free tier. Grimoire exposes your campaign as a connector; Claude reads it on every relevant query, scoped to one campaign per OAuth grant, enforced server-side. The three-click setup below works identically with ChatGPT and Cursor, with one per-client UI difference.

Add a custom connector

In Claude, ChatGPT, or any MCP client with custom-connector support, open Settings → Connectors and paste:

https://api.ttrpg.bot/mcp

Sign in, pick a campaign

Your client opens the Grimoire consent screen. Sign in, choose which campaign the AI may see, click Approve. Access is scoped to that one campaign, enforced server-side.

Ask it about your world

"Who knows about the cult?" "What was the queen's reaction in session 4?" "Generate three rumors that fit my current city." Your client reads live and answers from your data.

Full setup guide →

New to AI-assisted GMing? Read AI for Dungeon Masters for the longer story on what "AI for DMs" means as a design choice, with comparisons to AI-as-DM products that work differently.

What this gives your AI

Whatever you ask. Live, structured, in your world.

MCP is a protocol. Connect Grimoire to a frontier model and that model gets live, structured control of your campaign. The workflow is whatever you invent.

Tier 1 · the fast wins

Notes in. Entities out.

Paste a paragraph of session notes. The AI parses it into NPCs, locations, factions, and threads, then writes them straight into your campaign. The location you mentioned three sessions ago is suddenly searchable.

Tier 2 · the deeper plays

Model reactions in your canon.

Ask how an NPC reacts to a betrayal and the AI reads their actual motivations, actual alliances, actual history with the party. Project House Vale's next move. Generate rumors that fit your city, not generic fantasy.

Tier 3 · the MC-possibilities

Chain MCPs together.

Pipe your last session into a slideshow MCP and a voiceover MCP for an automated recap. Hook a calendar MCP and the bot reminds you to prep. Compose Grimoire with whatever your client already has installed.

We focus on one thing: making sure Grimoire can capture whatever's unique about your story and hand it to AI in a form the AI respects. You pick which AI and how it works. A baked-in "TTRPG bot AI" would always lag the frontier. This never does.

Most systems remember text.
Grimoire models the world.

Notion organizes notes. Grimoire organizes worlds. Same idea, different layer.

Grimoire respects whatever your world is. Memory as currency. Dreams that alter geography. Recursive timelines. Gods that only exist when worshipped. Cities alive as organisms. Your AI sees those rules as canon, not as flavor.

Why MCP, not just a chat

Context-efficient by design.

Most TTRPG GMs already use AI by pasting notes into a fresh chat. That falls apart when context fills up, when the chat compacts, or when you start a new conversation and the model forgets. Grimoire is built so the AI pulls only what it needs, on demand, from the structured truth.

	Using AI without Grimoire (single chat)	Grimoire MCP
Setup	New chat, paste your notes, hope they fit	One OAuth click. The connector stays put.
Data freshness	Snapshot of whatever you last pasted	Live from your campaign on every call
World structure	Limited to recent documents and chat history	14 typed entities, your schema, your canon
Stays in canon	Until the chat compacts or moves on; sessions still contradict	The AI defers to your data, not its training, every call
Context efficiency	Re-paste lore each session, hope it fits the window	Pulled on demand. Only the slice the AI asks for.
Player AI access	No safe way to share	Visibility tiers in the data model today. First-class player accounts shipping next.

Grimoire's job is to give your AI the most efficient view of your campaign possible. Where you take it from there is yours. The MCP tools tell the AI not to invent details you didn't ask for, so parsing notes adds your facts, not the model's guesses.

Under the hood

The actual tool calls

Walk through the calls your client makes, left to right, in sequence, with realistic timing. Switch tabs to see two different ways AI clients use Grimoire MCP.

User → AI client

"How would Queen Mira react if her brother betrayed her?"

1~3s

get_constitution

World truths loaded: magic, gods, founding rules.

→

2~8s

get_narrative_state

Where the story is now: recent sessions, open threads, canon.

→

3~13s

search_campaign

Found Queen Mira and her brother Cyrus.

→

4~18s

get_entity

Mira's full record: motivations, secrets, ties to Cyrus.

→

5~25s

get_knowledge_graph

Political ties: Crown loyalist, Cyrus turned Opposition.

→

6~40s

client models

Combines the above to derive how Mira would react.

↓

Result · ~45s

An in-character reaction grounded in Mira's actual motivations and her history with Cyrus, not a generic queen-betrayed-by-brother trope. Respects what's canon, what's secret, what's already happened.

Visibility tiers wrap every read.

Trust by design

The boring stuff that matters

When you're handing your campaign to a robot, the fundamentals are the feature.

Free on both ends

Grimoire never charges you for AI. Grimoire's free tier covers MCP, and the free tiers of Claude and ChatGPT both support one custom connector. The whole experience can be tried for free.

Visibility-aware

DM secrets stay DM secrets even when your players query. Three visibility tiers wrap every layer of context Grimoire exposes.

No training, ever

Your campaign data never enters anyone's training pipeline. Grimoire only serves data when it's queried. Prompts live entirely in your client's session.

Switch AI assistants freely

Want voice? Add it to Claude Desktop. Want agents? Use Claude Code. Want a different model? Use any MCP-compatible AI assistant. Your campaign doesn't move.

Questions, answered

The MCP page FAQ

What is MCP?

Model Context Protocol — an open standard from Anthropic that lets AI clients (Claude, ChatGPT, Cursor, others) read live data from external services through tool calls instead of pasted context. Grimoire is the TTRPG-specific MCP server: your campaign data, queryable by any compliant AI client.

Do I need to install Node.js or edit config files?

No. Grimoire MCP uses OAuth 2.1 plus streamable HTTP transport. You add it as a custom connector in your AI client's settings, sign in once through the Grimoire consent screen, and it's connected. No terminal, no JSON config, no Node.js, no tokens to paste.

Which AI clients work with Grimoire MCP?

Any MCP-compatible client. Tested in production: Claude (desktop and web), ChatGPT (Plus and Pro with custom connector support), Cursor. Grimoire is listed in the official MCP Registry as bot.ttrpg/grimoire and on Smithery as ttrpg/Grimoire, so any client that pulls from those directories sees it.

How is this different from just using AI without Grimoire?

Without Grimoire, your AI works from whatever you've pasted into the current chat. It's a fresh start every session — re-paste lore, re-explain who matters, hope the context window holds. When the chat compacts or you start a new one, the model forgets, and answers start to contradict earlier sessions. With Grimoire MCP, the AI pulls only the slice of your world it needs, on demand, from the structured source of truth. No re-pasting. No context bloat. The next conversation picks up where the canon is, not where the last chat ended.

Does Grimoire replace the Dungeon Master?

No. Grimoire is AI-assisted, not AI-replaced. The AI helps you prep, recall canon, draft recaps, and project NPC moves between sessions. At the live table, you run the game. This is a structural design choice, not a feature limit. The products that try to replace the DM are a different category; Grimoire is solidly in the 'AI for the human DM' category. The longer version of this argument lives on /ai-for-dungeon-masters/.

How is this different from other AI campaign tools like LoreKeeper, Tabletop Arc, or LitRPG Adventures?

Two structural differences. First, the AI integration model: tools like LoreKeeper ("Arcane Intelligence powered") and Tabletop Arc ("AI memory layer") bake their own AI in, which means you're locked to their chosen model and you pay whatever they pay for tokens. Grimoire is bring-your-own-client via MCP — connect Claude, ChatGPT, or any MCP-compatible client and you get the frontier model directly, no markup, and your client improves the day the vendor ships a new model. Second, the role: content generators like LitRPG Adventures produce one-shot assets (NPCs, dungeons, items) that you copy into your campaign. Grimoire is the live structured campaign itself — the AI reads it, writes to it, and traverses its graph. Different layer.

Is my campaign data used to train AI models?

No. Grimoire only serves your campaign data when your AI client queries it, and the data lives in your client's session. The protocol itself is not a training pipeline. Whether your AI client trains on session content is your client's policy, not Grimoire's.

What does it cost?

Grimoire's free tier includes MCP access. The free tiers on Claude.ai and ChatGPT both support one custom connector. Grimoire never charges for AI tokens — bring your own client. End-to-end free to try.

Can my players use the AI connection?

Not yet. The MCP connection today is scoped to the GM's account: the GM connects their AI client, the AI sees that GM's campaign. The visibility tier system exists in the data model and the in-app Player Portal, but first-class player accounts that can connect their own AI client to a campaign they're invited to are planned for the next iteration.

Is Grimoire free to use with Claude or ChatGPT?

Yes. Grimoire's free tier covers Grimoire MCP: unlimited entity storage and live AI queries on one campaign. Claude.ai's free tier covers one custom connector. ChatGPT's free tier also supports custom MCP connectors. The full AI-assisted D&D campaign workflow is free end-to-end on both sides.

Build your TTRPG bot. Free.

Grimoire's free tier includes MCP. The free tier of Claude or ChatGPT supports one custom connector. That connector can be Grimoire. Your feedback actively shapes the product.

Start free → How Grimoire MCP works Read the MCP docs

Listed in the official MCP Registry as bot.ttrpg/grimoire, and on Smithery.