Nexa AI Chat

👉 Click the banner or [start here] to get going.
Use code BLUE40 and unlock your 40% discount instantly.

Nexa AI (Minecraft Mod + Paper Plugin)

Nexa needs an AI key. Free options exist, and setup takes about 2 minutes.
Install Nexa and type /nexa hi. Nexa explains what it needs and gives you buttons: get a free key, paste it, done.

Nexa AI adds an AI companion to Minecraft that knows your game: the recipes, items and mods that are actually loaded, plus any guide your modpack ships.

• Works as a Fabric / Forge / NeoForge mod (clients + servers)
• Also available as a Paper plugin

---

👋 A quick note from the dev (v2.5)

Hey everyone! If you've used Nexa before, you'll notice this update is a big one. Honestly, it's pretty much a new mod.

The biggest change: the free built-in AI is gone. Every message anyone sent through it was a message I paid for, and as more of you started using Nexa, that bill got bigger than I could keep covering. I didn't want Nexa to just stop working one day when the money ran out, so I made the hard call: Nexa is now fully Bring Your Own Key.

I know that sounds like extra work, so I tried hard to make it painless:

• Google Gemini gives you a free key. Nexa walks you through it in chat, with buttons. About 2 minutes.
• Running Ollama or LM Studio? Nexa finds it on its own. No key, no cost, nothing leaves your PC.
• 54 one-click setups for popular AI services. Pick one, paste a key, and you're connected.
• Your chat now goes straight to the AI you chose, not through my server. It's faster and more private.

While I was at it, I rebuilt Nexa around what it's best at: actually knowing your game. It looks up real recipes and items (modded ones too) instead of guessing, and modpack makers can teach it about their pack.

Thanks for sticking with Nexa. If something breaks or feels confusing, come tell me on Discord. I read everything. ❤️

---

Features

• Chat with Nexa: /nexa <message>, or press N for the chat and settings screen.
• Answers from your pack: Nexa looks up the real recipes, uses, items and mods in your game, modded ones included, instead of guessing. It also knows which mods (or, on Paper, plugins) are installed and what each one is for.
• Server instructions: drop your rules, purpose and key places into config/nexa/instructions.md, and Nexa follows them in every conversation.
• Pack guide: modpacks can drop Markdown pages into config/nexa/knowledge/, and Nexa uses them to answer progression and FAQ questions.
• Guided setup: with no AI connected, Nexa walks you through it in chat. It also detects Ollama or LM Studio running on your PC.
• Bring your own AI: works with any server that speaks one of four standard formats: Google Gemini, OpenAI-compatible, OpenAI Responses or Anthropic Messages.
• Agent modes: ask-before-act (default; world changes need your OK) or autonomous.
• Tools: teleport, locate, time, weather, effects, waypoints, screenshot analysis and more, with permissions.
• Memory: conversations survive restarts, and old chat is summarized.
• Friendly errors: a bad key, rate limit or outage is explained in plain words, with a [Fix] button.
• Fully configurable: one file, config/nexa/nexa.toml. Server owners and pack authors decide everything: auto messages, idle messages, limits, daily caps, tools and the persona.
• Pack integration: add custom tools with JSON files (no code), or with Java / KubeJS, which can also give Nexa short always-on notes about a mod.

---

Getting an AI key

Quick setup	Format	Cost	Key
Google Gemini (recommended)	gemini	free key	https://aistudio.google.com/apikey
OpenAI	responses	pay as you go	https://platform.openai.com/api-keys
Anthropic Claude	anthropic	pay as you go	https://platform.claude.com/settings/keys
OpenRouter	openai	many models, some free	https://openrouter.ai/settings/keys
Ollama / LM Studio on your PC	openai	free, runs locally	no key; detected automatically

Plus 49 more one-click setups (all OpenAI-compatible, just paste the key): Ollama Cloud, Groq, Cerebras, SambaNova, Together AI, Fireworks AI, DeepInfra, NVIDIA NIM, Hugging Face, Inception Mercury, Vercel AI Gateway, GitHub Models, Requesty, Poe, AI/ML API, NanoGPT, Chutes, DeepSeek, Mistral AI, xAI Grok, Moonshot Kimi, Z.ai GLM, Alibaba Qwen, MiniMax, Cohere, Meta Llama API, StepFun, Upstage Solar, Novita AI, Hyperbolic, Nebius Token Factory, SiliconFlow, Featherless, Venice AI, Baseten, FriendliAI, Parasail, Nscale, Inference.net, Scaleway, OVHcloud AI Endpoints, IONOS AI Model Hub, and local llama.cpp, vLLM, Jan, KoboldCpp and LiteLLM. /nex-config ai presets lists them all with key links.

When a service's model names change often, the setup leaves the model blank: once the key is saved, Nexa asks the service which models the key can use and picks a quick everyday one. /nex-config ai models [filter] (or List in the setup screen) shows them all so you can switch.

Anything else: pick the format your server speaks and enter its address, key and model.

Format	Endpoint it calls	Works with
gemini (Google Gemini)	POST {base_url}/models/{model}:generateContent	Google AI Studio (free key)
openai (OpenAI-compatible)	POST {base_url}/chat/completions	OpenRouter, Groq, Ollama, LM Studio, vLLM, most others
responses (OpenAI Responses)	POST {base_url}/responses	OpenAI, and servers that copy it
anthropic (Anthropic Messages)	POST {base_url}/messages	Anthropic (Claude)

In singleplayer, Nexa asks you directly. On a server, the admin connects it once for everyone. Players who can't set it up are told to ask an admin. Free keys have the service's own rate limits.

---

Supported Targets

• Fabric: Minecraft 26.3 and 1.21.1
• NeoForge: Minecraft 26.3 and 1.21.1
• Forge: Minecraft 26.3 and 1.20.1
• Paper: Minecraft 26.3

Java: 26.3 runs on Java 25, 1.21.1 on Java 21, 1.20.1 on Java 17.

---

Commands

Chat

• /nexa <message>: chat with Nexa.
• /nexa confirm / /nexa cancel: approve or cancel queued actions (ask-before-act mode). Previews also have clickable [Yes] / [No] buttons.
• /nexa-gui (or /nex-gui, or the N key): opens the chat and settings screen. /nexa-gui setup opens the AI Setup tab, /nexa-gui settings opens the settings, and /nexa-gui off / /nexa-gui on turn the N key screen off or on for you.

AI setup (/nex-config ai)

For the server admin (or the console), or the owner of a singleplayer/LAN world:

• ai / ai status: format, server address, model, thinking and the masked key.
• ai presets: the one-click setups, with key links.
• ai use <service> [model]: fill in everything for one of 54 known services (gemini, openai, anthropic, groq, deepseek, mistral, openrouter, ollama, ...).
• ai models [filter]: list the models your key can use; click one to switch.
• ai key <api-key>: save the key. Nexa checks it with one tiny request and says "Connected" only if it works.
• ai format <gemini|openai|responses|anthropic|none>, ai url <address>, ai model <name>, ai thinking <level|clear>: any other server.
• ai test, ai local (use Ollama / LM Studio on this machine), ai clearkey, ai disconnect.
• The old byok name still works.

Other settings (/nex-config)

• reload: re-read config/nexa/nexa.toml, instructions.md and the knowledge and tools folders.
• clearchat: clear your conversation history.
• feedback <message>: send feedback to the developer (once per 24 hours).
• mode show / mode <ask|autonomous>: your personal agent mode, if the server allows it.
• limits status|maxrequests <1..15>|cooldown <seconds>
• custom name <name> / custom prompt <prompt> / custom show / custom reset
• automessages enable|disable|status

Changing a server-wide setting needs nexa.admin / OP, or being the singleplayer/LAN world owner. With the mod, regular players only see their own options in the settings screen; the AI setup, limits and persona are admin-only.

---

For modpack authors and server owners

All the settings live in config/nexa/nexa.toml. Ship it with your pack:

• Set the name and persona for your pack's theme.
• Turn join greetings and idle messages on or off, and set the idle window.
• Set limits: requests per message, cooldown, and messages per player per day.
• Choose the default mode, and whether players can change it.
• Disable tools, or make them admin-only.
• Turn off update checks for packs that pin versions.

Then write config/nexa/instructions.md (the rules and facts Nexa always follows), and add config/nexa/knowledge/*.md guide pages and config/nexa/tools/*.json custom tools. The full guide, with an example config, is in docs/PACK_AUTHORS.md.

You may include Nexa in any modpack. It's MIT licensed, and you don't need to ask.

---

Built-in tools

• Pack lookups (everyone): findRecipes, findUses, itemInfo, searchItems, listMods and packGuide.
• Player info (everyone): getPlayerState, getInventorySummary, getEnvironmentInfo, getGameRules, getNearbyEntities, getAgentContext and analyzeScreenshot.
• Waypoints (everyone): saveLocation, removeLocation and listSavedLocations.
• World changes (admins; asks first in ask-before-act): locate, teleport, timeSet, weather, giveEffect and spawnEntity.

---

Permissions

• nexa.use: use /nexa, /nex-config and the GUI (default: everyone).
• nexa.admin: server-wide settings and world-changing tools.
• Works with LuckPerms on every platform. Without it, nexa.admin falls back to OP (or the world owner in singleplayer).

---

Installation

• Fabric: Fabric Loader + Fabric API, then put nexa-fabric*.jar into mods/.
• Forge / NeoForge: put the jar into mods/.
• Paper: put nexa-paper*.jar into plugins/ and restart.

*Server-side features work with only the server jar. Install the client mod for the GUI (key N) and screenshot analysis.*

Upgrading from 2.x? Your old BYOK settings (chatmc_byok.json) move into nexa.toml automatically. If you were using the free built-in AI, run /nexa hi once and connect a key.

---

Data and privacy

• Your chat goes straight to the AI service you connected, or stays on your PC with a local model. The Nexa developer never sees it. That service's terms apply.
• Conversation history is saved in the world folder (chatmc_history_<uuid>.json).
• API keys are stored in config/nexa/nexa.toml on the machine running Nexa. They're never logged, and they're shown masked in game.
• The Nexa update server only receives a version check, which you can turn off with update_check = false. Feedback is sent only when you run /nex-config feedback, and it includes your message and player name. You can turn that off with feedback_command = false.

---

Support

If you run into issues, have feedback, or want to contribute, join the Discord.

Discord: https://discord.gg/Wvst4znsgk