blender-mcp

Blender MCP

Control a running Blender instance from Hermes via socket on TCP port 9876.

Setup (one-time)

1. Install the Blender addon

curl -sL https://raw.githubusercontent.com/ahujasid/blender-mcp/main/addon.py -o ~/Desktop/blender_mcp_addon.py

In Blender: Edit > Preferences > Add-ons > Install > select blender_mcp_addon.py Enable "Interface: Blender MCP"

2. Start the socket server in Blender

Press N in Blender viewport to open sidebar. Find "BlenderMCP" tab and click "Start Server".

3. Verify connection

nc -z -w2 localhost 9876 && echo "OPEN" || echo "CLOSED"

Protocol

Plain UTF-8 JSON over TCP -- no length prefix.

Send: {"type": "", "params": {}} Receive: {"status": "success", "result": } {"status": "error", "message": ""}

Available Commands

type	params	description
execute_code	code (str)	Run arbitrary bpy Python code
get_scene_info	(none)	List all objects in scene
get_object_info	object_name (str)	Details on a specific object
get_viewport_screenshot	(none)	Screenshot of current viewport

Python Helper

Use this inside execute_code tool calls:

import socket, json

def blender_exec(code: str, host="localhost", port=9876, timeout=15):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((host, port))
    s.settimeout(timeout)
    payload = json.dumps({"type": "execute_code", "params": {"code": code}})
    s.sendall(payload.encode("utf-8"))
    buf = b""
    while True:
        try:
            chunk = s.recv(4096)
            if not chunk:
                break
            buf += chunk
            try:
                json.loads(buf.decode("utf-8"))
                break
            except json.JSONDecodeError:
                continue
        except socket.timeout:
            break
    s.close()
    return json.loads(buf.decode("utf-8"))