bootstrap.py

"""Blender startup script for headless HF Spaces (NOT blender -b).

Run under a virtual display so Blender's GUI event loop runs and the
MCP addon's bpy.app.timers dispatcher fires (upstream explicitly refuses
-b background mode for this reason):

    xvfb-run -a blender --python /app/bootstrap.py

What it does:
  1. Enables the bundled blender_mcp addon (expects addon.py copied to
     the Blender scripts/addons dir as blender_mcp.py by the Dockerfile).
  2. Sets the socket port (env BLENDER_PORT, default 9876).
  3. Calls the addon's own start operator (blendermcp.start_server) —
     no clicks needed.
Blender stays alive afterwards (GUI loop under xvfb), serving MCP clients
until the container stops.
"""

import os
import sys

import bpy


def main() -> None:
    port = int(os.environ.get("BLENDER_PORT", "9876"))

    bpy.ops.preferences.addon_enable(module="blender_mcp")

    scene = bpy.context.scene
    if hasattr(scene, "blendermcp_port"):
        scene.blendermcp_port = port

    bpy.ops.blendermcp.start_server()

    running = getattr(getattr(bpy.types, "blendermcp_server", None), "running", False)
    print(f"BOOTSTRAP: blendermcp_server running={running} port={port}", flush=True)
    if not running:
        print("BOOTSTRAP FATAL: server did not start", flush=True)
        sys.exit(1)


if __name__ == "__main__":
    main()