Living, Breathing Worlds
Narrative, Evolved
We've built a new type of engine that breathes life into worlds at scale. It creates endless streams of characters and stories from coherently evolving simulated cultures, unlocking immersive narratives that respond to player and agent actions—all at a fraction of the cost of ML-only systems.
Now we're developing an API to let anyone build and explore custom worlds, from prehistory to sci-fi and everything in between.
Use Cases
INTERACTIVE FICTION
Transform any work into a collaborative exchange with your audience. Be inspired by worlds that take on a life of their own, evolving organically. You can retain significant narrative control or hand over the reins completely; either way, giving your audience agency enriches the experience for everyone.
RPG CAMPAIGNS
From worldbuilding to story opportunities and consistency, WorldsAPI helps GMs every step of the way. Curate narrative threads from entire populations of characters with their own lives, goals, and relationships that evolve between sessions. Less prep, more unforgettable moments with your players.
GAME DEVELOPMENT
Players expect living worlds that respond meaningfully to their choices. Generate immersive content while maintaining narrative coherence and as much control as you need to tell your story. Ship games where every NPC has genuine motivations and every player action creates authentic ripple effects.
SYNTHETIC DATA
Generate massive amounts of data from tailored populations with unprecedented cultural, social, and behavioral depth. From improving language models to preparing human responders for complex interactions, our systems provide controllable, ethical training data at scale.
WORLD MODELS
Create custom reproducible environments where models encounter millions of causally coherent interaction scenarios. Develop world models that understand the complexity of human culture and behavior, which far outstrips that of physical systems, and assess their potential impacts.
Our Technology
WorldsAPI is powered by a first-of-its-kind Culture Engine that simulates all aspects of individual lives for entire populations. It produces dynamically evolving constraints that can be used directly by humans or integrated with language models to make worldbuilding and narrative tasks easier.
The result? Higher-quality interactions, genuine impacts, reduced costs.
MASSIVE POPULATIONS
Simulate 1M+ individuals at high speed, each with their own lived experience. The engine maintains causal coherence regardless of scale, ensuring satisfying butterfly effects and reproducible results.
INFINITE DIVERSITY
Seed the engine to produce realistic characters and narratives for any kind of world, from prehistory to the present and fantasy to sci-fi. Or let it surprise you—you get the keys to an infinite cultural space.
REDUCED COSTS
Minimize the environmental and unit costs of your narrative applications. The engine uses algorithms founded on anthropological first principles to produce constraints at scale, confining token usage to the edges.
Join Early Access
Build a world that evolves beyond its design. Get early access to our API.