BlendJob is a local Job Server runtime for Blender extensions. It runs long tasks in an isolated Python environment and provides a reusable Blender Operator workflow with progress, cancellation, FIFO scheduling, result delivery, and server lifecycle management.
It is designed for AI inference, model downloads, media processing, geometry computation, and other work that benefits from running outside Blender's main process.
A BlendJob feature has three parts:
- A Server Handler defines the Python task.
JobRuntimeconfigures the Server entrypoint, environment, and storage.- A Blender Operator inherits
runtime.JobOperatorBase, submits parameters, and applies the result on Blender's main thread.
Register a backend task:
# example_job/server/__init__.py
from blendjob import JobServer
server = JobServer("Example Job Server")
@server.job("double")
def double(context, parameters):
context.progress(0.5, "Calculating")
return {"value": parameters["value"] * 2}Configure the Blender runtime:
# example_job/__init__.py
from pathlib import Path
from blendjob import JobRuntime
runtime = JobRuntime(
"server:server",
entrypoint_root=Path(__file__).parent,
storage_root=Path.home() / ".example-job",
environment={
"python": "3.10",
"packages": ["numpy==2.4.2"],
},
namespace="example_job",
)Define the Blender Operator:
# example_job/__init__.py (continued)
import bpy
JobOperatorBase = runtime.JobOperatorBase
class DoubleValue(JobOperatorBase, bpy.types.Operator):
bl_idname = "example_job.double_value"
bl_label = "Double Value"
job_type = "double"
value: bpy.props.IntProperty(default=21)
def request(self, _context):
return {"value": self.value}
def response(self, _context, result):
self.report({"INFO"}, f"Result: {result.value['value']}")The Getting Started guide provides a complete, ready-to-run Blender extension layout with registration and UI code.
Install BlendJob in a regular Python project with pip or uv:
python -m pip install blendjobuv add blendjobThe default package has no dependencies, which keeps the Blender-side runtime lightweight. Install the server extra when creating a FastAPI app or running the server directly in a regular Python environment:
python -m pip install "blendjob[server]"For a Blender extension, bundle the BlendJob wheel in wheels/ and declare it in blender_manifest.toml:
wheels = ["./wheels/blendjob-0.1.13-py3-none-any.whl"]Supported runtime targets are Python 3.10+, Windows x64, macOS arm64, and Linux x64.
uv sync
uv run pytest
uv build
uv run mkdocs build --strictVersioned documentation uses Mike:
uv run mike deploy --update-aliases 0.1 latest
uv run mike set-default latestBlendJob is available under the MIT License.