bim-blender

Convert 3D files without opening Blender, or drive a live Blender session from the command line. Supports FBX, glTF/GLB, OBJ, USD, and BLEND natively — IFC read/write requires the free Bonsai add-on. Your AI assistant can batch-convert files, load IFC models, and place geometry in a scene you're actively working in.

Headless format conversion and live Blender control via a local TCP bridge. One install command sets up a managed Blender 4.5 LTS — no manual Blender setup required.

Install managed Blender: bim blender install — downloads Blender 4.5.10 (~395 MB) to %LOCALAPPDATA%\bim-cli\blender\. No admin, no system-wide Blender install required. Run once, idempotent.

Add IFC support: bim blender install --component bonsai — adds the free Bonsai extension (~118 MB).

How it works

Two modes in one driver:

Headless (static): bim blender convert spawns blender --background, runs the conversion, exits. No visible window. Suitable for batch pipelines.
Bridge (live): bim blender launch opens Blender with its UI visible. A background Python server binds a random local port and writes a discovery file. bim blender exec sends Python snippets over TCP — changes appear in the open Blender window in real time.

Convert — format matrix

Supported conversions. * = requires bim blender install --component bonsai.

From	To	Requires Bonsai
IFC	FBX, glTF/GLB, OBJ, USD, BLEND	Yes *
FBX	glTF/GLB, OBJ, USD, BLEND	No
glTF/GLB	FBX, OBJ, USD, BLEND	No
OBJ	FBX, glTF/GLB, USD, BLEND	No
USD	FBX, glTF/GLB, OBJ, BLEND	No
BLEND	IFC *, FBX, glTF/GLB, OBJ, USD	IFC only *

exec globals

These variables are pre-injected into every bim blender exec snippet:

Variable	Type	Availability
`bpy`	Blender Python API module	always
`bpy.context`	active context	always
`bpy.data`	data block access	always
`bonsai`	Bonsai module	when Bonsai installed
`tool`	`bonsai.tool` helpers	when Bonsai installed
`ifcopenshell`	IfcOpenShell module	when Bonsai installed

Return a value by assigning to _. Non-JSON-serializable results fall back to repr().

Verbs

Verb	What it does
`bim blender install`	download and install managed Blender 4.5.10 LTS
`bim blender install --component bonsai`	add Bonsai IFC add-on to the managed install
`bim blender install --component all`	Blender + Bonsai in one step
`bim blender upgrade`	upgrade managed install to latest pinned versions
`bim blender doctor`	check install health; each failed check includes a `fix` command
`bim blender status`	show installed versions and paths
`bim blender convert --in FILE --out FILE`	headless format conversion; format detected from extension
`bim blender launch`	open managed Blender with UI; waits for bridge to bind
`bim blender instances`	list live Blender instances with pid, port, open file
`bim blender exec --code "PYTHON"`	run Python against a live Blender instance
`bim blender exec --file script.py`	run a .py file
`bim blender kill --pid PID`	terminate a specific Blender instance
`bim blender kill --all`	terminate all managed Blender instances

Example: batch IFC to glTF

bim blender install --component all
bim blender convert --in model.ifc --out model.glb

Example: co-edit with an agent

bim blender launch
bim blender exec --code "bpy.ops.mesh.primitive_cube_add(location=(2, 0, 0))"
bim blender exec --code "_ = bpy.context.active_object.location[:]"

The cube appears in the open Blender window. The second command reads back whatever you've moved it to.

For agent use: /blender/llms.txt