Introducing the Character Engine
Today we're publicly introducing the Character Engine — model-agnostic infrastructure that transforms any foundation model into a believable, persistent AI character.
Most AI characters suffer from the same fundamental problems: they forget everything between sessions, their personality is just a static system prompt, and they only respond when spoken to. The Character Engine solves all three.
The engine wraps any LLM with 7 parallel context layers — persistent memory, evolving personality, emotional modeling, relationship tracking, goal systems, world knowledge, and autonomous behavior. Your LLM handles language. We handle everything that makes a character feel alive.
It works with OpenAI, Anthropic, Google, Mistral, and any OpenAI-compatible API including self-hosted models via vLLM, Ollama, or TGI. Swap providers without rewriting your character logic — same personality, same memories, different brain.
Key capabilities include sub-200ms memory retrieval at p95, 50+ personality dimensions modeled through Big5 traits and custom emotional modeling, and zero cold starts — characters never forget who you are.
The Character Engine is built for two primary use cases. For gaming, it powers NPCs with persistent memory and evolving relationships — they remember player choices across sessions, develop opinions, hold grudges, and form alliances. For AI companions, it enables relationships that deepen over months with proactive outreach, personality evolution, and relationship modeling.
Deploy anywhere: mobile apps via REST API with SSE streaming, game engines like Unity and Unreal, messaging platforms including Telegram, WhatsApp, and Discord, or direct REST API access with OpenAI-compatible streaming.
The engine is already battle-tested in production powering Pocket Souls, our flagship consumer product where AI companions remember you, check in on you, and grow alongside your journey.
Explore the platform at platform.sonz.ai or reach out at [email protected] to discuss how the Character Engine can power your AI characters.