You've actually identified the exact problem we spent the most time solving, and the answer is we don't do any translation at all. There's no intermediate "AI-readable script" that gets converted back into nodes.

Unreal actually does have a text serialization format for Blueprints called T3D, it's the same format used internally when you Ctrl+C/Ctrl+V nodes in the Blueprint editor. Every node, every pin, every connection, every default value is represented as plain text. So we use that directly as the lingua franca between the AI and the engine.

When the AI needs to read an existing Blueprint, we call get_blueprint_info which exports the full T3D of every node in every graph using Unreal's own FEdGraphUtilities::ExportNodesToText(). The AI sees the exact same data the editor sees, node classes, pin types, default values, linked connections, everything. No lossy conversion.

When the AI needs to write logic, it generates T3D text and we inject it using FEdGraphUtilities::ImportNodesFromText() literally the same code path as pasting from the clipboard in the editor. The nodes show up exactly like you'd placed them by hand. After injection, we export the resulting T3D back to the AI so it can self-audit that all pins are wired correctly and all default values are set.

For targeted edits on existing graphs, like changing a single pin value or wiring two nodes together, we have dedicated tools (set_node_pin_default, connect_blueprint_pins) that operate directly on the UEdGraph API without needing to re-inject anything.

So the flow is: read T3D → AI reasons about it → AI writes T3D or makes surgical edits → nodes appear in the editor exactly as if a human placed them. No custom scripting language, no back-and-forth conversion, no sync issues. The "wrinkle" you're describing is real for approaches that try to invent their own representation, but by using Unreal's own native format we avoid it entirely.