No, it is not possible to call a specific version of a subworkflow from a main workflow. Subworkflows are inlined at registration time, meaning the subworkflow's code and structure are embedded into the parent workflow, and versioning is not applied at the subworkflow call level. Only the version of the parent workflow matters at execution; you cannot specify a different version for a subworkflow within the workflow definition. If you need to execute a specific version of a workflow from another workflow, you must use a launch plan, which triggers an external workflow execution and allows you to specify the version explicitly. For more details, see the explanation of subworkflows and external workflows in the Flyte documentation and the distinction between subworkflows and launch plans in the Flyte fundamentals guide. Would you like a step-by-step example of how to use launch plans to achieve version-specific workflow execution? Sources: - Flyte documentation - Flyte fundamentals guide 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.

To create a launch plan that triggers an external workflow (i.e., executes a specific workflow version as a separate execution), use the

LaunchPlan.get_or_create()

method in Flytekit, referencing the target workflow and specifying any default or fixed inputs as needed. When you invoke this launch plan from another workflow, it will start a new, external execution of the specified workflow, decoupled from the parent workflow’s execution context. Example:

from flytekit import LaunchPlan

external_lp = LaunchPlan.get_or_create(
    workflow=target_workflow,
    name="external_workflow_lp",
    default_inputs={"param": value}
)

Calling

external_lp()

within a workflow will trigger the external workflow execution. For more, see the subworkflows and external workflows guide. Would you like a full example with workflow definitions? Sources: - subworkflows and external workflows guide 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.

Here’s a step-by-step example of creating and using a launch plan to trigger an external workflow execution in Flyte: 1. Define the target workflow (the one you want to trigger externally):

from flytekit import task, workflow

@task
def add_one(x: int) -> int:
    return x + 1

@workflow
def increment_wf(x: int) -> int:
    return add_one(x=x)

2. Create a launch plan for the target workflow:

from flytekit import LaunchPlan

increment_lp = LaunchPlan.get_or_create(
    increment_wf,
    name="increment_lp",
    default_inputs={"x": 10}
)

3. Use the launch plan in another workflow to trigger the external execution:

from flytekit import workflow

@workflow
def main_wf() -> int:
    # This triggers an external execution of increment_wf via the launch plan
    return increment_lp()

When

main_wf

runs, it will launch a new, independent execution of

increment_wf

using the launch plan, and the result will be returned to

main_wf

. You can override default inputs by passing arguments to

increment_lp()

. This approach ensures the triggered workflow runs as a separate execution, with its own execution ID and context, as described in the Flyte subworkflows and external workflows guide. Sources: - Flyte subworkflows and external workflows guide 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.