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App version: 3.20250901

Create a run

To create an experiment run, use the Run constructor.

For example, to create a run that belongs to the seabird-flying-skills experiment, use:

from neptune_scale import Run


if __name__ == "__main__":
    run = Run(experiment_name="seabird-flying-skills")

  • The name can contain any Unicode character, including /, , ., :, ;, &, and |.

  • The line if __name__ == "__main__": ensures safe importing of the main module. For details, see the Python documentation.

Then, to track experiment metadata, call a logging method on the run object:

for step in epoch:
    # your training loop
    acc = ...
    loss = ...

    run.log_metrics(
        data={"metrics/accuracy": acc, "metrics/loss": loss},
        step=1,
    )

For details, see Log metadata.

To get a link to the experiment in the Neptune web app:

run = Run(experiment_name=...)
run.get_experiment_url()

For details, see Construct Neptune URLs.

Set target project​

To specify the Neptune project, use the project argument:

run = Run(
    experiment_name="seabird-flying-skills",
    project="team-alpha/project-x",  # replace with your workspace and project name
)

You can also save the project name as an environment variable. For details, see Get started.

Set custom run ID​

To override the auto-generated run identifier with a custom one, pass a string to the run_id argument:

run = Run(
    experiment_name="seabird-flying-skills",
    run_id="astute-kittiwake-23",
)

The custom run ID provided to the run_id argument must be unique within the project. It can't contain the / character.

Pass existing ID​

If a run with the ID passed to run_id already exists, Neptune continues logging to that run.

For details, see Resume a run.

What's the difference between sys/id and sys/custom_run_id?
  • sys/custom_run_id is the run identifier you set manually via the run_id argument of the Run constructor. It's auto-generated if not provided.
  • sys/id is a legacy run identifier based on the project key. It will be removed in a future release and can be ignored.

View runs in the app​

In the All runs tab, by default, Neptune displays the latest run of each experiment.

To show all runs, switch from Experiments to Runs:

All runs tab in the Neptune app with a highlighted button for switching between all runs and experiment runs.

You can save your table configuration as a custom view, which makes it easier to work on the runs later.

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