Example: Flows Manager

10 min

End-to-end walkthrough: create a Node-RED flow, start it, download a backup of its file, then clean up.

Setup

from litmussdk import flows

The flow content itself (nodes, wires, tabs) is managed via Node-RED's API directly; this SDK only handles the flow lifecycle (create, start/stop, update, delete) and file download.

1. Create a Flow

create_flow returns a stopped, empty flow. The Node-RED UI or API is then used to populate its tabs.

flow = flows.create_flow(
    name="My Flow",
    secret="my-flow-secret",
    memory_limit=256,
)
flow_id = flow["id"]
print(f"Created flow {flow_id}")

2. Start the Flow

flows.start_flow(flow_id)

The flow is now running. Calling start_flow again raises an error.

3. List Flows and Find Yours

all_flows = flows.list_flows()
me = next(f for f in all_flows if f["id"] == flow_id)
print(f"name={me['name']} memory_limit={me['memory_limit']}")

4. Update a Flow

flows.update_flow(
    flow_id=flow_id,
    name="My Flow (renamed)",
    memory_limit=512,
)

5. Download the Flow File (4.0.x+)

The flow's .json definition can be downloaded as bytes for backup or air-gap deployment. As of SDK 2.6.0, this returns proper bytes; prior versions silently corrupted binary content via UTF-8 decode.

content: bytes = flows.download_flow_file(flow_id)

with open("my_flow.json", "wb") as f:
    f.write(content)

Logs work the same way:

logs: bytes = flows.download_flow_logs(flow_id)
with open("my_flow.logs", "wb") as f:
    f.write(logs)

Both functions raise UnsupportedVersionError on Litmus Edge 3.x.

6. Delete Flow Artifacts (4.0.x+)

Clean up individual files without deleting the flow itself:

flows.delete_flow_logs(flow_id)
flows.delete_flow_node_modules(flow_id)
flows.delete_flow_credentials(flow_id)
flows.delete_flow_flows_json(flow_id)

7. Stop and Remove the Flow

flows.stop_flow(flow_id)
flows.remove_flow(flow_id)