Got it — sounds like you changed your flow’s parameters but the UI isn’t showing them. In Prefect 3.x, the run form in the UI reads parameters from the deployment’s stored

parameter_openapi_schema

. That schema only updates when you redeploy. Quick path to fix and verify: - Redeploy after changing your

@flow

signature - CLI:

prefect deploy

- Or programmatically:

from prefect import flow

    @flow
    def my_flow(x: int, y: str = "default"): ...

    my_flow.from_source(
        "<https://github.com/owner/repo>",
        entrypoint="path/to/file.py:my_flow",
    ).deploy(
        name="prod",
        work_pool_name="your-pool",
    )

- Verify the deployment has the new schema

prefect deployment inspect "my-flow/prod"

Look for

parameter_openapi_schema

and confirm your new param is there. - Refresh the UI - Close/reopen the deployment page or hard-refresh. The UI should auto-refresh after a successful update, but a reload ensures it. If it’s still not showing: - Make sure you’re opening the correct deployment/version in the UI (new parameters are versioned per deployment). - If using

from_source

with Git, ensure you committed/pushed the change and are deploying from the branch/ref that contains it. - Double-check you’re not using removed 2.x commands like

prefect deployment build

(use

prefect deploy

in 3.x). If you can, share: - The exact

flow/deployment

name - Output of:

prefect deployment inspect "flow-name/deployment-name"

- Your Prefect version (

prefect version

) Docs for reference: - Deployments in Prefect 3 - Flow parameters - Deployment versioning