Getting started

In this tutorial you'll build a "patrol if safe" behavior tree from scratch. By the end you'll know how to drag nodes, connect them, edit ports, and export to JSON.

Time: ~5 minutes. Prerequisites: a modern browser. No account, no install.

1. Open the editor

Head to bteditor.dev. You should see a node palette on the left, an empty canvas in the middle, and a toolbar above the canvas. If the language doesn't auto-detect to English, pick it from the 🌐 dropdown in the top right.

2. Drag a Sequence onto the canvas

In the left palette, expand Composite Nodes. You'll see Sequence, Selector, Parallel, RandomSelector, and RandomSequence. Drag Sequence onto the canvas.

Sequence runs its children left-to-right and only returns SUCCESS if all children succeed. It's the right starting point when you have a sequence of mandatory steps.

3. Add the safety check

Expand Condition Nodes and drag IsEnable onto the canvas. Place it to the left of the Sequence. The editor auto-layouts in horizontal mode by default; you can switch to vertical with the ⇄ button in the toolbar.

Conditions are leaves — they have no children. They return SUCCESS or FAILURE based on external state. In a real robot, IsEnable would be wired to a "system healthy" flag from your telemetry bus.

4. Connect IsEnable → Sequence

Hover over IsEnable until the blue output port appears on its right edge. Click and drag from that port to the input port on the left edge of Sequence. A light gray line should appear. Release.

That's a parent → child relationship. When you tick the tree, Sequence will call IsEnable first.

5. Add the patrol action

Expand Action Nodes, drag Wait onto the canvas, and place it as a child of Sequence. Connect Sequence's output to Wait's input.

The Wait node has a duration port. Click the node body to expand it; you'll see a text field next to "duration". Type 2.0 and press Enter. This makes the patrol tick wait 2 seconds between checks.

6. Export the tree

Click the Export button in the header. The default format is JSON; you can also pick XML or BehaviorTree.CPP XML from the radio buttons.

For a tiny tree like ours, the JSON will look like:

{
  "root": {
    "name": "Sequence",
    "type": 0,
    "children": [
      { "name": "IsEnable", "type": 3 },
      { "name": "Wait", "type": 1, "ports": { "duration": 2.0 } }
    ]
  }
}

You can copy the JSON to clipboard or download it as behavior_tree.json. Either format can be re-imported later with the Import Tree button.

7. Re-import to verify round-trip

Hit Clear to wipe the canvas. Then Import Tree, paste the JSON, and confirm. Your tree should come back exactly as you left it.

What next?

• Node types reference — what each node does and when to use it.
• Replay NDJSON logs — capture a real run and step through it.
• Define custom node types — extend the library with your own.
• Reactive control patterns — when to reach for behavior trees vs. state machines.

← Docs index Node types →

Last updated: 2026-07-09