Unreal AI Runtime: The first unified interactive AI toolkit for game developers
Today, we’re excited to be launching our Unreal AI Runtime SDK - the first unified solution for game developers building realtime interactive AI experiences. No more stitching together multiple AI plugins, managing separate provider APIs, or spending all your time fighting AI instead of building your game.
With the Unreal AI Runtime, you can now:
- Start working immediately with foundational AI building blocks like speech-to-text (STT), text-to-speech (TTS), and LLMs
- Get access to hundreds of models across various model providers with a single API key
- Easily create AI pipelines, such as a speech to speech pipeline, with an intuitive visual graph editor
- Leverage pre-built templates for common use cases like AI NPCs and chatbots
- Manage and optimize costs, latency, and quality through built-in observability and experimentation tools
The Unreal AI Runtime SDK is live now and available for download. We are also launching our Unity AI Runtime SDK for early access.
Why we built this
Inworld has been building for game developers since day one — starting with lifelike, interactive characters that could form relationships, express emotions, and respond naturally through voice. Along the way, we saw the biggest challenges developers faced when building engaging, realtime AI experiences:
- Keeping up with dozens of models and providers - Delivering a rich, multimodal AI often requires testing dozens of different models. The Unreal AI Runtime SDK unifies access to all major model providers under a single API key, so switching models is as easy as selecting from a dropdown.
- Easily customizing without reinventing the wheel - With pre-built templates and a modular design, you can customize or extend for your specific use case while starting from a production-ready, pre-optimized foundation. Our intuitive visual graph editor makes it easy for anyone—writers, designers, or developers—to customize logic, prompts, and behavior that define your AI interaction.
- Debugging non-deterministic AI responses - The Unreal AI Runtime's built-in observability tools, including logs, traces, and dashboards, make it easy to trace every step of your AI pipeline, understand latency, and pinpoint exactly where an issue occurred.
- Managing costs with scale - The Unreal AI Runtime helps manage those costs with dashboards that provide a unified view of your cost drivers and experimentation tools.
The Unreal AI Runtime was built to address these challenges for game developers, so you can spend more time building your game instead of building AI infrastructure.
What you can build
Engaging, conversational NPCs
Developer: Inworld team
SDK: Unreal AI Runtime
Motivation: Building a believable, real-time character is hard. We designed our Character, Metahuman, and Lipsync templates to handle all of this out of the box, optimizing for performance, realism, and responsiveness. It’s the fastest way to build a fully interactive, voice-driven character in Unreal.
Generative Survivor’s game
Developer: Brian Cox, Shuang Liang
SDK: Unity AI Runtime
Motivation: I wanted to challenge myself to create a fully generative game. This voice input triggers a series of LLM service calls, each using specialized prompts to search the asset libraries and select the most fitting options.
AI-powered decision making
Developer: Braeden Warnick
SDK: Unreal AI Runtime
Motivation: I wanted to explore making an NPC companion that can behave based on what they should do based on their character info.
Get started with Inworld Runtime
To get started building today:
- Download the AI Runtime SDK for Unreal or Unity and read the documentation
- Explore the Character template to add conversational capabilities to your NPCs
- Talk to our team for enterprise support.
We’re excited to see what games and experiences you bring to life!