Project Overview
Blender MCP Legacy is a modified build of the Blender Lab MCP add-on, which runs a local MCP (Model Context Protocol) server inside Blender so an AI client can control the scene. The official add-on requires Blender 5.1+, which rules out Intel Macs (x86_64) stuck on Blender 4.5 LTS. This port makes them compatible again.
Challenges & Goals
- Compatibility: Run the add-on on Blender 4.2 to 4.5, on Intel macOS, Windows and Linux.
- Minimal, auditable changes: The first commit holds the untouched upstream code and the second holds every modification, so they can be reviewed with a single
git diff. - Security transparency: Clearly document what differs from the official build.
Technical Details
- Extension manifest: Minimum Blender version lowered from 5.1.0 to 4.2.0 in
blender_manifest.toml. - Sandbox: The private hook
bpy.ops._op_create_function, missing in Blender 4.x, is read withgetattr. When absent, dangerous-operator blocking is skipped instead of crashing the add-on. This limitation is documented: only trusted clients should connect. - MCP server: Local TCP server (default
localhost:9876), also usable headless (blender --background --command blender_mcp). - Distribution: Ready-to-install zip via Install from Disk…, published as a GitHub release under GPL-3.0.