u/Sollimann

A little over 4 years ago I started Bonsai as a side project: a Rust library for building complex, deterministic AI behavior with behavior trees. It has since found its way into a wide range of applications.

The video shows two of them: on the left, a Titanfall 2 gameplay where all the players except the first person view is a NPC (bot) driven by Bonsai behavior trees. On the right (with sound), a robot from NASA lunabotics 2026 autonomously digging and dumping regolith in a simulated lunar environment – also powered by Bonsai.

A lot of the library's usefulness today comes from the community. Thanks to everyone who has contributed PRs, filed issues, and pushed it further than I would have on my own.

Repo link in the comments.

A little over 4 years ago I started Bonsai as a side project: a Rust library for building complex, deterministic AI behavior with behavior trees. It has since found its way into a wide range of applications.

The video shows two of them: on the left, a Titanfall 2 gameplay where all the players except the first person view is a NPC (bot) driven by Bonsai behavior trees. On the right, a robot from NASA lunabotics 2026 autonomously digging and dumping regolith in a simulated lunar environment – also powered by Bonsai.

A lot of the library's usefulness today comes from the community. Thanks to everyone who has contributed PRs, filed issues, and pushed it further than I would have on my own.

Repo link in the comments.

What the library does

If you not familiar with the library, its basically a Rust implementation of behavior trees which are a great way to build deterministic AI — they're widely used for things like robotics, game NPCs and any agent that needs predictable, debuggable decision-making.

What's new

We just introduced python bindings and a live view of the behavior tree. Also, we have added tons of new examples to get you going.

For more, the project here: https://github.com/sollimann/bonsai

We've just shipped v0.12.0 of `bonsai-bt`, and the big addition this release is live visualizations in the browser — you can now watch the state of your behavior tree update in real time as it ticks, including which nodes are running, succeeding, or failing.

For anyone unfamiliar: behavior trees are a great way to build deterministic AI — they're widely used for things like robotics control loops, game NPCs, and any agent that needs predictable, debuggable decision-making. The new visualizer makes it a lot easier to actually see what your tree is doing and catch issues without sprinkling print statements everywhere.

The visualizer is gated behind a feature flag. Add it to your `Cargo.toml` like this:

```toml

[dependencies]

bonsai-bt = { version = "0.12.0", features = ["visualize"] }

```

For more, see repo: https://github.com/Sollimann/bonsai