fluss
The python client for fluss, the Arkitekt workflow service: designing, storing and running workflows (flows) that wire the actions of your apps together.
Installation
pip install fluss
The flow executor is an optional extra, because it needs rekuest while the plain client does not:
pip install "fluss[engine]" # run flows (fluss.engine)
pip install "fluss[python]" # also run flows written as Python source
With arkitekt, pip install "arkitekt[rekuest,fluss]" brings it in.
Design
A flow is a graph: argument nodes feed reactive and action nodes, whose outputs reach return
nodes. Flows live in workspaces, and every execution of a flow is a run. fluss is the client
for that graph — it queries and mutates flows, workspaces and runs on the fluss server — and
fluss.engine is what executes one.
Usage
Every fluss operation is a method of the Fluss client, in a blocking and an a-prefixed async
flavour (fluss.get_flow(id), await fluss.aget_flow(id)).
In an arkitekt app
Add the service to your app and ask for fluss: Fluss; the client is injected by annotation. Flows
and runs travel between actions by id (@fluss/flow, @fluss/run, @fluss/pythonflow,
@fluss/pythonrun), so an action can take and return them directly:
from arkitekt import App, run
from fluss import Fluss, fluss_service
from fluss.api.schema import Flow
app = App("flow-inspector", "0.1.0", services=[fluss_service])
@app.action
def describe_flow(flow: Flow, fluss: Fluss) -> str:
"""Describe Flow"""
return f"{flow.title} in workspace {flow.workspace.id}"
if __name__ == "__main__":
run(app)
An app built with the fluss service also offers the generic Run Flow action (interface
run_flow), so it can execute any flow it is handed (Run Python Flow too, with the python
extra).
From a script
from arkitekt import easy
from fluss import fluss_service
with easy("my-script", fluss_service) as fluss:
for flow in fluss.flows(limit=10):
print(flow.id, flow.title)
The engine
fluss.engine executes a flow as a generic rekuest action: given a flow and a dict of arguments it
yields the flow's returns, so a workflow can be called like any other action.
A flow run is registered as a rekuest workflow: if the agent running it dies, it is resumed, and the node calls that already finished return their recorded results instead of running again. Each call is keyed by its node and how often that node ran, so concurrent branches are found again whichever order they finish in.
from fluss.engine import run_flow, arun_flow
It imports rekuest at module level, so install fluss[engine] to use it. Importing plain fluss
never requires rekuest.
Python flows
fluss.engine.python (the python extra) validates and runs flows written as Python source in a
Monty sandbox: async def main(...) calls the actions of its manifest by alias.
- Run Python Flow is a workflow too. Each action call is keyed by the action, a digest of its
arguments and how often that exact call was made before, so a resumed run finds its calls
again without depending on how its gathered calls interleave. The sandbox's
randomseed is fixed per run, so the run makes the same calls again. One case remains: identical calls in parallel branches may trade results on resume. The calls downstream of them then run again, which repeats anIRREVERSIBLEaction if one is among them. - Its actor shares one Monty worker pool across runs.
printoutput reaches the task log while the run goes on. A cancelled run cancels the calls it has in flight and endsCANCELLED. - Publishing a version makes it runnable, not an action. To call a version like any action,
deploy it onto an agent that hosts
run_python_flow:
from fluss.engine.python.client import acreate_python_flow_from_source, adeploy_python_flow, amanifest
actions = await amanifest({"segment": segment_hash}, rekuest)
flow = await acreate_python_flow_from_source(source, actions, fluss, title="Segment", publish=True)
await adeploy_python_flow(flow, rekuest, runner=run_python_flow_implementation_id)
Testing
uv run pytest -m "not integration" # no server needed
uv run pytest -m integration # a real fluss server via dokker
See RELEASING.md for how versions are cut.
1 maintainer
Metadata
1 maintainer
Release files for fluss 6.0.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| fluss-6.0.0.tar.gz | 91.0 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| fluss-6.0.0-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 201.3 kB
Release files / fluss-6.0.0.tar.gz
| Download URL | fluss-6.0.0.tar.gz |
|---|---|
| Size | 91.0 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
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uv/0.13.1 {"installer":{"name":"uv","version":"0.13.1","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"Ubuntu","version":"24.04","id":"noble","libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":true}
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Release files / fluss-6.0.0-py3-none-any.whl
| Download URL | fluss-6.0.0-py3-none-any.whl |
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| Size | 110.2 kB |
| Tags | Python 3 |
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SHA-256 checksum How to use checksums |
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uv/0.13.1 {"installer":{"name":"uv","version":"0.13.1","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"Ubuntu","version":"24.04","id":"noble","libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":true}
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