Powered by Local AI | Runs Entirely Offline

The World Bends
to Your Imagination

Nexus is a fully self-contained AI text adventure engine that runs on your machine | no cloud, no subscriptions to AI APIs, no limits. Just you, your story, and a 12-billion-parameter Game Master.

One-time purchase · $8.99 · Yours forever · No AI API costs ever

// Screenshots from live sessions

Nexus Main Screen
Main Dashboard - Initialize Construct
Curated Constructs
Curated Constructs - AI-Generated World Seeds
Gameplay Narrative
Live Gameplay - Dark Narrative Prose
Reply Screen
Real-Time Response - Active Memory State
Engine Setup
One-Time Setup - Streams the Model to Your Machine
Nexus Main Screen
Main Dashboard - Initialize Construct
Curated Constructs
Curated Constructs - AI-Generated World Seeds
Gameplay Narrative
Live Gameplay - Dark Narrative Prose
Reply Screen
Real-Time Response - Active Memory State
Engine Setup
One-Time Setup - Streams the Model to Your Machine
100% Offline After Setup
Native Windows Executable
Zero Terminal Commands
Infinite Unique Stories
Persistent Save System
Romance & NPC Memory

An AI Game Master That Lives on Your PC

Nexus ships as a single double-click executable. It silently boots a local AI engine, downloads a 12-billion-parameter language model once, then opens a cinematic browser interface - all without you ever touching a terminal or paying ongoing API fees.

Every story you tell stays on your machine. Your inventory, your companions, your choices - all tracked with mechanical precision by a Game Master who remembers everything and enforces real consequences.

12B
Parameter Model
Unique Worlds
0
Monthly API Fees
1-Click
Setup Required
Nexus gameplay

Everything a Game Master Needs.
Nothing You Don't.

Strict Mechanics Engine
Real inventory enforcement. You cannot use what you don't have. HP, Stamina, and equipment all tracked as hidden control tags that the engine parses on every response.
Living Character Memory
Every NPC you meet is stored in a persistent Characters dictionary. Relationships evolve based on your chosen Romance Preference (Male/Female/Both/None). The GM remembers who you crossed, who you charmed, and who you owe a debt.
Branching Save System
Auto-saves after every exchange. Name your own save slots for branching paths. Load any save and diverge into an entirely different timeline.
Forge Any Reality
Type any world concept - or choose from AI-generated suggestions spanning Dark Fantasy, Sci-Fi, Cyberpunk, and beyond. The engine constructs lore, factions, and opening scenes in seconds.
Intelligent Model Fallback
If the primary model hits an error, Nexus silently queries your local Ollama install, filters compatible models, and reroutes the request - no interruption, no crash, no message.
Dark Fiction Tone Enforced
The system prompt enforces atmospheric dark fiction prose on every turn. Lethality is real but not cheap - the GM applies severe consequences without resorting to instant arbitrary death.
One-Time Purchase, Offline Forever
Download the engine and it's yours forever. No DRM, no activations, and fully unlocked offline. No re-authentication, no internet required to play.
Zero Setup for End Users
Double-click Nexus.exe. That's it. The app boots Ollama as a hidden process, polls the health endpoint, and only opens the browser once everything is confirmed ready.

From Download to First Adventure
in Under 20 Minutes

01
Purchase & Download
After checkout, you will be instantly redirected to a secure download page to get the Nexus engine ZIP file. No waiting, no manual emails.
02
Extract & Boot
Extract the folder anywhere on your machine and double-click Nexus.exe. The engine boots a local Node.js server, spawns Ollama silently, and waits until the AI is ready.
03
Download the AI Model (One-Time)
Nexus streams the NemoMix-Unleashed-12B model (12.13 GB) directly from Hugging Face with a real-time progress bar, speed indicator, ETA counter, and rotating commentary. Cancel and resume any time. This only happens once.
04
Forge Your Reality & Play
Set your callsign and romance preference. Type any world concept or pick a Curated Construct. The Game Master opens your scene in seconds. Every choice matters. Every NPC remembers. Every item is real.

See the Engine in Motion

Dashboard
Initialize Construct Dashboard
Curated Constructs
AI-Generated Curated Constructs
After reply
After Sending a Reply - Sidebar Stats Active
Model download
One-Time Model Download - Nexus Engine Setup

One Price. Infinite Worlds.

No subscriptions. No AI API costs. No usage limits. Buy once and the engine is yours, forever, running entirely on your hardware.

✦ Complete Edition
$ 8.99 / once

Everything you need to run an infinite AI-driven text adventure on your own machine - no ongoing costs, ever.

  • Nexus.exe - native Windows executable
  • Automated AI Model Manager (Downloads open-source models)
  • Full game engine: HP, Stamina, Inventory, NPC Memory
  • Branching save system - unlimited named slots
  • AI-generated world suggestion cards (refreshable)
  • Automatic model fallback & engine recovery
  • Offline forever after one-time activation
  • All future updates included
  • Instant access to the DRM-free game download

What Players Are Saying

"I’ve bounced between a bunch of AI RPG tools, but Nexus is the first one that actually feels like playing with a real GM. If I don’t have an item, I can’t magically use it. Actions actually have consequences too. I betrayed a merchant early on and the game brought it back up way later in a way that completely caught me off guard."

MR
Marcus R.
Tabletop RPG Veteran

"Setup was way easier than I expected. I just opened the app, pasted my key, let the model download, and I was playing within minutes. No messing around with terminals or config files. Everything worked out of the box."

EL
Elena L.
Writer & Gamer

"I’m usually pretty skeptical about local AI apps, especially anything managing Ollama in the background. But after checking how they handled it, I was impressed. It only closes Ollama if it launched it itself, which means it doesn’t interfere with my own setup. Small detail, but it shows real care went into this."

DK
Dev K.
Software Engineer & AI Enthusiast

"The writing quality surprised me the most. I ended up playing as a disgraced doctor in this grim Victorian plague city, and the atmosphere stayed consistent the entire time. The game never drifted out of character, even after long sessions."

AT
Amara T.
Fiction Writer

"Honestly, the value is kind of ridiculous. I paid once and that was it. Since it runs locally, I don’t have to worry about subscriptions or paying every time I want a long roleplay session. I’ve already gotten weeks out of it."

JM
Jordan M.
Budget-Conscious Gamer

"The save system is awesome. I reached a major decision in my campaign, made two separate saves, and played out both outcomes. It genuinely felt like exploring alternate timelines in my own story."

SP
Sam P.
Dungeon Master & Worldbuilder

Questions & Answers

Do I need an internet connection to play?
Only once - during the initial model download. After that, Nexus runs 100% offline. The AI model lives on your hard drive, the game is DRM-free, and the engine is fully self-contained.
What are the system requirements?
Nexus runs on Windows with at least 16 GB of RAM recommended (the 12B model is quantized for performance). A dedicated GPU will significantly speed up response times but is not required - the model can run on CPU, though slower. You'll need ~15 GB of free disk space for the model file.
What is Ollama and do I need to install it?
Ollama is the local AI runtime that Nexus uses under the hood. It's bundled with or automatically managed by the Nexus executable - you do not need to install it separately. The application spawns and manages Ollama as a hidden background process. If you already have Ollama installed, Nexus is smart enough to detect that and won't interfere with your existing setup.
How long does the model download take?
It depends on your internet speed. The model is 12.13 GB. On a 50 Mbps connection, expect around 30–40 minutes. On faster connections, significantly less. The download screen shows real-time speed, progress percentage, GB downloaded, and estimated time remaining. You can cancel and resume at any time.
Is this a subscription? Will I be billed monthly?
Absolutely not. Nexus is a one-time purchase of $8.99. You will never be charged again. There are no API costs, no monthly fees, no usage limits. The AI runs on your hardware using your compute. We earn nothing from you after the initial sale.
Are my stories and data private?
Completely. Every conversation, save file, inventory state, and character memory lives exclusively on your local machine. Nothing is sent to any server during gameplay. Your stories are yours - we have no access to them, and neither does anyone else.
Can I use my own Ollama models?
Yes - the automatic model fallback system queries your local Ollama install if the primary NemoMix model encounters an error. It filters compatible generative models and reroutes silently. For power users, this means you can experiment with other models in your Ollama library.
What happens if I lose my download files?
The game is completely DRM-free. If you lose your files or need to reinstall on a new machine, simply contact us via the support email with your purchase receipt and we'll send you a fresh download link.
How many save slots do I get?
Unlimited. Save files are JSON files stored in a local saves directory. You can create as many named save slots as you want, branch your story at any decision point, and maintain dozens of parallel campaigns simultaneously.
Do future updates cost extra?
No. All future updates to Nexus are included in your one-time purchase. As we improve the engine, add features, or update the model configuration, you'll receive those updates at no additional cost.

Get in Touch

Questions about the engine, licensing, refunds, or technical support? We respond within 24 hours, usually much faster.

Support Email
support@nexusengine.io
Response Time
Within 24 hours · Usually same day
Coverage
Available worldwide · All time zones