Building Blueprints with the Agent

The Blueprint toolsets let the agent author Blueprint classes end to end: create the asset, add variables, components, functions and event graphs, set defaults, and compile. This turns "I need an actor that does X" into a working, compiled Blueprint without you touching the graph editor.

What the agent can do

• Create Blueprint classes from a parent class (Actor, Pawn, ActorComponent, UserWidget, etc.) at a content path.
• Add components (mesh, collision, light, custom) and configure their properties.
• Add variables with a type, category, default value, and exposure flags.
• Add functions and events, wire up nodes, and set default values on the class.
• Compile and save so the class is ready to place or reference.

These tools are reflected from the engine, so names follow the Verb+Noun convention (create / add / set / compile). Use describe_toolset on the Blueprint toolset for the exact signatures in your engine build.

Typical workflows

Create a simple actor Blueprint

"Create a Blueprint called BP_Pickup based on Actor in /Game/Blueprints. Give it a StaticMesh component using SM_Sphere, a float variable Value defaulting to 10, and a bool bConsumed. Compile it."

The agent creates the asset, adds the component and mesh, adds the two variables with defaults, then compiles — you get a placeable, compiled BP_Pickup.

Extend an existing Blueprint

"Open BP_Pickup and add an integer variable Tier exposed on spawn, then recompile."

The agent adds the variable, sets its exposure flag, and recompiles in place.

Wire behavior

For graph logic, describe the behavior and let the agent add the event/function nodes:

"On BeginPlay, log Value and hide the mesh if bConsumed is true."

Tips

• Pick the right parent class. Tell the agent the base class explicitly (Actor, Pawn, ActorComponent, UserWidget) — it changes which components and overrides are valid.
• Always compile. Adding members marks the Blueprint dirty; the agent should compile (and save) before you place or reference it. Ask it to "compile and save" to be safe.
• Reuse, don't duplicate. The agent can call the Asset toolset's FindAssets to check whether a similar Blueprint already exists before creating a new one.
• Variable types use Unreal type names. Float, Boolean, Integer, Vector, plus object/struct references by path. The agent will translate plain-language types, but being explicit avoids ambiguity.

Discover the actual signature

Use list_toolsets, then describe the relevant fully qualified toolset. Replace the placeholder below with a name returned by that catalog:

{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"describe_toolset","arguments":{"toolset_name":"<name returned by list_toolsets>"}}}

Call the selected tool using toolset_name, tool_name and arguments, as shown in the tools reference. Engine-backed authoring can use the hidden backend where supported; preview, viewport and interactive actions require their editor context. Compile and save explicitly, then verify the relevant runtime result.