psai

psai® is an interactive music engine for videogames, intended for composers and developers making adaptive soundtracks. Its playback controls can adjust intensity, recombine musical segments automatically, pause, and respond to gameplay logic. The Unity edition is written in C# without native code, and the maker says it works on all Unity target platforms. A native C++ SDK is available for Windows only; interested users are directed to contact the maker about evaluation or licensing. The regular and Pro versions use the same Unity engine, while Pro adds the standalone editor for creating projects from scratch. That editor is listed for Win/Mac and requires Music Engine Pro and Pro User Registration. Downloads include a demo soundtrack and eight free music themes. The maker says Unity use across a customer's projects carries no further costs or royalties, with one copy per company seat. However, users who have not purchased the engine through the Unity Asset Store may use the editor only non-commercially. The site links to manuals, API documentation, tutorials, and a Unity forum.

psai® offers adaptive music playback for Unity games, with a separate Windows-only native SDK. The standalone editor adds project creation, but its access and commercial-use terms are important to check.

psai® is aimed at videogame composers and developers who need music that responds to gameplay. The Unity version suits Unity projects; the native C++ SDK is limited to Windows.

psai is a specialized interactive music engine for videogame composers and developers building adaptive soundtracks, especially in Unity. Its free Unity engine is a useful starting point, but creating projects from scratch requires Pro and the editor’s commercial-use terms can constrain how teams work.

Overview

psai makes game music respond to play through intensity control, musical-segment recombination, pausing and gameplay-driven playback logic. That focus suits teams shaping an interactive score; it is not presented as a general-purpose audio system.

The regular and Pro versions use the same Unity engine. Pro adds the standalone editor for creating projects from scratch, and using that editor requires both Pro and Pro User Registration. A demo soundtrack and eight free music themes offer material to work with, but do not replace Pro when authoring new projects.

Key features

• Adaptive playback: Intensity control and automatic recombination let music change with gameplay rather than remain fixed. These are the core reasons to consider psai for an interactive soundtrack.
• Unity integration: The C# engine uses no native code, and its maker says it works on all Unity target platforms. That makes it a clear fit for Unity projects across their chosen targets.
• Native C++ SDK: The separate native SDK is Windows-only, and interested developers must contact the maker about evaluation or licensing. Teams needing a native SDK on other platforms should look elsewhere.
• Source and developer resources: Customers receive the full source code; the FAQ identifies the .NET Google protobuf implementation as the only internally referenced DLL. A manual, API documentation, tutorials, Unity forum and technical-support email are provided, though the posted Unity Asset Store EULA limits support services to customers with a special agreement.

Pricing

The engine itself is the same in the regular and Pro versions, so Pro’s value is authoring access and updates rather than a different Unity runtime. The editor’s EULA says users who did not purchase the engine through the Unity Asset Store may use the editor only non-commercially, including unlimited testing for future commercial use. Teams planning commercial editor use should check that condition before committing.

Platforms

The Unity implementation is written in C# without native code, with the maker stating it works on all Unity target platforms. psai also documents Unity and native C++ APIs, but the native SDK runs on Windows only. The editor download is for Windows and Mac and requires Pro and Pro User Registration.

Who it's for

psai is aimed at videogame composers and developers who want a soundtrack to react to gameplay, particularly teams building in Unity. The free engine works for projects that do not need the standalone editor; teams creating projects from scratch need Pro. It is a weaker fit for developers seeking a cross-platform native C++ SDK or a general audio solution.

Pros and cons

• Pro: Adaptive intensity, segment recombination, pausing and gameplay logic give composers several ways to make music follow the action.
• Pro: The free Unity engine can be used across projects without royalties, with one company copy per seat.
• Pro: Customers receive source code, alongside API documentation, tutorials and a manual.
• Con: Creating projects from scratch requires Pro, and the editor has a non-commercial restriction for users who did not buy through the Unity Asset Store.
• Con: Native C++ support is limited to Windows, and support services under the posted Unity Asset Store EULA require a special agreement.

Alternatives

Browse the Game Audio Middleware directory for more options. Choose Amplitude Audio SDK if you want free, open-source software under Apache-2.0; its separate Studio Free plan is for non-commercial use. Audiokinetic Wwise may suit teams wanting a free Indie tier with a game-production budget below $250K, unlimited sound files and a per-title license.

Live Link Face is another free option for iOS and Android. Meta XR Audio SDK is free and has stated compatible versions for Unity, Unreal, FMOD and Wwise. OpenAL Soft is a free LGPL-licensed implementation of the OpenAL 3D audio API.

Reactional Engine offers a free plan with forum and Discord support and a required splash screen; its Studio plan uses custom pricing. SoLoud is free for commercial use, with modification and redistribution permitted under the ZLib/LibPNG license. Steam Audio SDK is free to all developers, subject to its license agreement.

Verdict

Choose psai if you are composing or developing a gameplay-responsive soundtrack in Unity and want a free engine with project-wide use and no royalties. Its main draw is focused adaptive playback; look elsewhere if you need native C++ beyond Windows, or check the Pro editor’s commercial-use terms before relying on it to create a commercial project.