A Minecraft AI companion that plays with you

Sei is an AI gaming companion: a free desktop app for Mac and Windows whose companions play games with you. In Minecraft, your companion joins your world as a real second player. They mine, build, and fight alongside you, talk with you out loud on voice, and remember your time together.

macOS Windows

Free to start · Open source

Sei companion Lyra standing next to the player in a Minecraft village at sunset — Lyra, a Sei companion, joins the player's Minecraft world as her own player with her own skin.

What your AI companion does in Minecraft

Your companion is not a chat window on the side. They join your world as their own player, so they can see what is around them and act on it. Ask in chat or just say it on a call:

Follow you and explore caves, villages, and the Nether together.
Gather and mine wood, stone, and ore veins, and hand you what they found.
Craft and smelt tools and materials from what is in their inventory and nearby chests.
Build walls, shelters, and simple structures next to you.
Fight and defend against mobs, eat when they are hungry, and sleep when night comes.
Look around and react to what they see, and look things up on the web when you ask a question they cannot answer.

Each companion also has their own personality. Some are cheerful, some are sarcastic, and some will tell you the Nether is hostile and pointless. You can meet the ones Sei matches you with, create your own, or import a companion you already talk to on another platform.

Minecraft chat where the player asks Sei companion Marv if he likes the Nether and Marv answers that it is hostile and pointless — Marv, standing next to a Nether portal, has opinions about the Nether.

Talk to them while you play

Start a voice call and play at the same time. Your companion hears you, answers out loud, and keeps playing while you talk, like a teammate on Discord. Calls work in English, Chinese, Japanese, Korean, French, and Spanish, and you can also type in Minecraft chat or in the app.

A companion that remembers you

Sei companions keep a long-term memory of your time together: the base you built, the time you both fell into lava, what you told them about your day. That memory stays on your computer and comes with them into every game you play together, not just Minecraft.

More than a Minecraft bot

Minecraft is one of several games your Sei companion plays with you. The same character, with the same memory of you, also plays chess, takes turns drawing and guessing in Draw!, farms with you in Stardew Valley, and survives with you in Don't Starve Together. With Backseat, they also watch you play games they cannot join, such as Elden Ring or Hollow Knight: Silksong, and talk with you about them. More games are on the way. See all of Sei.

How to play Minecraft with an AI companion

Download Sei for macOS or Windows and sign in, or pick local mode and use your own model.
Choose a companion. Sei matches you with up to four characters, or you can make your own.
Open Play together, then Minecraft. The first time, Sei adds a Sei profile to your Minecraft Launcher for you.
Start Minecraft with that profile, load a world, press Esc, and choose Open to LAN.
Summon your companion. They join the world as a second player and say hi.

Requirements

Computer	macOS (Apple Silicon or Intel) or Windows
Minecraft	Minecraft: Java Edition, 1.8 to 26.3 (most releases in that range; the app shows which). Bedrock is not supported.
World	A world on the same computer, opened to LAN. Vanilla worlds work. Forge and NeoForge worlds, and worlds that make every player install their mods, turn Sei away.
Mods	None needed for your companion to join. Optional: the Sei profile that Sei's setup adds to your Minecraft Launcher (Fabric Loader and the CustomSkinLoader skin mod, for Minecraft 1.14 to 26.1) shows each companion's own skin.
Cost	Free to start. Open source and free to self-host with your own API key or Ollama.

Sei vs Minecraft AI mods

Last checked 2026-10-19

Most AI companions for Minecraft come in one of three forms. A mod from CurseForge or Modrinth goes into your mods folder and runs inside the game, so you need the right mod loader and a matching Minecraft version. An open-source bot project such as Mindcraft runs from a terminal on your computer and connects a bot to your world, using your own AI key. A companion app such as MinePal or Sei runs next to Minecraft and connects its companion to your world as a player.

Sei is a companion app, not a mod. Your companion joins a world you open to LAN the same way another player would, so it works with plain vanilla Minecraft: Java Edition from 1.8 to 26.3. Nothing has to go into your mods folder for it to join. Sei's setup can add an optional Sei profile to your Minecraft Launcher, with Fabric Loader and the CustomSkinLoader skin mod, and that only exists so you see each companion's own skin.

Sei makes this page. We took every fact about the other projects from their own pages on 2026-10-19 and link the pages we used. Where a page did not say something, the table says "not listed". If something here is out of date, tell us on Discord and we will fix it.

Name	What it is	What you install	Minecraft	Voice	AI model
Mindcraft	Open-source bot project on GitHub	Node.js and the project files. You add an API key to a settings file and start it from a terminal.	Java Edition up to 1.21.11, world opened to LAN. Online servers need an official Minecraft account for the bot.	Spoken replies if you set a text-to-speech model	Your own API key (OpenAI by default, many providers) or a local model with Ollama
MinePal	Companion app	The MinePal desktop app. Bedrock players join its hosted crossplay lobbies.	Vanilla and modded Java Edition, 1.8.8 to 26.3. Bedrock through its lobbies.	Voice chat in 55 languages	MinePal's plans: free tier with 20 chat credits a day, paid from $2.99/month
Player2 AI NPC	Mod on CurseForge and Modrinth	A mod loader (Fabric; Forge and NeoForge builds are listed too), Fabric API, Cardinal Components, PlayerEngine, the mod, and the Player2 desktop app running in the background	Java Edition 1.20.1 to 1.21.1	Characters have voices from the Player2 platform; you talk to them in chat	Through the Player2 app
Sei	Companion app for Mac and Windows	The Sei app. The Sei launcher profile for skins is optional, and Sei sets it up for you.	Vanilla Java Edition 1.8 to 26.3 (most releases), world opened to LAN on the same computer. No Forge, NeoForge, or Bedrock.	Voice calls: it hears you and answers out loud, in 6 languages	Hosted plans with no key (Free plan, no card), or your own API key, or Ollama on your computer
VoxelMind	Open-source Fabric mod (MIT)	Fabric, Fabric API, and the mod	Java Edition 1.21 to 26.2 on Fabric. Also works on servers that run the mod.	Not listed	Your pick: Player2, its own Sparks credits, OpenRouter, or a local model (Ollama, LM Studio)

On a phone, swipe the table sideways to see every column.

Sources, checked 2026-10-19: Mindcraft README, minepal.net, Player2 AI NPC on Modrinth, voxel-mind.com.

Where mods and the others are stronger than Sei

Modded worlds. A mod runs inside your modpack, and MinePal lists modded Java support. Sei is turned away by Forge and NeoForge worlds and by worlds that require content mods on every player.
Bedrock, consoles, and phones. MinePal's crossplay lobbies take Bedrock players. Sei is Java Edition on a Mac or Windows computer only.
Servers. VoxelMind works on servers that run the mod, and Mindcraft can join online servers with its own Minecraft account. Sei joins a world opened to LAN on your own computer.
Tinkering. Mindcraft is built to be changed: you can edit its prompts and bot profiles and pick from many model providers.
Languages and price. MinePal lists voice chat in 55 languages to Sei's 6, and paid plans from $2.99 a month. Mindcraft and VoxelMind are free software; you pay your AI provider or run a local model.

Where Sei is different

No mod loader to manage. Your companion connects over Open to LAN, so your world can stay vanilla and there is no mod to match to your Minecraft version. The app updates itself.
Talk out loud. Voice calls are built in. Your companion hears you and answers while it keeps playing.
No API key on the hosted plans. Start on the Free plan with no card, or bring your own key or a local model with Ollama.
One companion in many games. The same character, with the same memory of you, also plays Stardew Valley, Don't Starve Together, chess, and Draw!, and watches other games with Backseat. Its memory is stored on your computer.
Open source. The app is on GitHub under AGPL-3.0.

Comparing companions beyond Minecraft, such as Questie AI or HakkoAI? See the comparison of AI gaming companions.

Questions

Is there a free AI companion for Minecraft that talks with you?

Yes. Sei is a free desktop app for Mac and Windows. Its AI companion joins your Minecraft: Java Edition world as its own player after you open the world to LAN. Start a voice call and it hears you and answers out loud while it follows you, mines, builds, and fights mobs, and it remembers your past sessions. The Free plan costs $0, needs no card, and includes voice calls within its weekly allowance. You don't install mods or paste an API key yourself: Sei adds a Sei profile to your Minecraft Launcher the first time. Bedrock, console, and mobile editions are not supported.

Is there an AI bot that plays Minecraft with you?

Yes. Sei is a desktop app for Mac and Windows whose AI companion joins your Minecraft: Java Edition world as its own player, with its own skin. It follows you, mines and gathers, crafts and smelts, builds, fights mobs, hands you items, eats, and sleeps, and it talks with you in chat or on a voice call. More than one companion can join the same world.

Can I get an AI companion in Minecraft without mods?

Yes. Sei's companion is not a mod. It joins your Minecraft: Java Edition world as its own player when you open the world to LAN, so it works in plain vanilla worlds from 1.8 to 26.3. The one optional extra is the Sei profile that Sei's setup adds to your Minecraft Launcher, with Fabric Loader and the CustomSkinLoader skin mod, so you see each companion's own skin. Sei installs it for you, and you can skip it. Bedrock is not supported.

Is there a Minecraft Java AI companion mod?

Yes, several. On CurseForge and Modrinth there are mods such as Player2 AI NPC (which also needs the Player2 app) and VoxelMind, and Mindcraft is an open-source bot project on GitHub that runs with your own API key. Mods need a matching mod loader and Minecraft version. If you would rather not manage mods, Sei is a desktop app whose companion joins a vanilla Java world over Open to LAN, with voice calls built in. This page compares them side by side.

Does Sei work with Minecraft Bedrock or Pocket Edition?

Not yet. Sei companions join Minecraft: Java Edition on macOS and Windows. Bedrock, console, and mobile editions are not supported.

Which Minecraft versions does Sei work with?

Sei can join Minecraft: Java Edition worlds from 1.8 to 26.3. That covers most releases in the range, and the app shows the exact list; a few older point releases are missing, such as 1.16 to 1.16.3. The optional Sei launcher profile that shows companion skins installs for 1.14 to 26.1. Bedrock, console, and mobile editions are not supported.

Does Sei work with Forge, Fabric, or modded worlds?

Sei joins vanilla worlds. Forge and NeoForge worlds turn it away, and so do Fabric worlds whose mods every player must have, which can include map mods such as Xaero's Minimap. Sei's own launcher profile runs on Fabric with only a skin mod, so worlds you open from it work. If you want a companion inside a modpack, a mod such as Player2 AI NPC or VoxelMind, or MinePal, which lists modded Java support, is the better fit.

Do I need an API key or to install mods myself?

No. On the hosted plans there is no API key to paste and no config file to edit. The first time you play, Sei's setup adds a Sei profile to your Minecraft Launcher for you, which is also how your companion shows up with their own skin. If you prefer to run everything yourself, local mode uses your own API key or a local model through Ollama.

Can I play with more than one AI companion?

Yes. You can bring more than one companion into the same world. They know about each other and can talk to each other as well as to you.

Is Sei a Minecraft mod?

Sei is a desktop app, not a mod you manage. Your companion connects to your world as its own player, the same way another player would join over LAN. Because the companion lives in the app, the same character can also call you, play chess, play Draw!, and come along to other games, with one memory across all of them.

Is Sei free?

Yes, you can start for free with no card. The app is open source, and you can self-host it for free with your own API key or a local model.

Deciding between Sei and a Minecraft mod? See Sei vs Minecraft AI mods above. For companions in other games, see our comparison of AI gaming companions.