Skip to content

API reference: PyTorch Ignite integration#

The NeptuneLogger class provided by the PyTorch Ignite library captures metadata that is generated when training and validating models with Ignite.


Creates a Neptune handler to log metrics, model and optimizer parameters, and gradients during the training and validation. It can also log model checkpoints to Neptune.


Name Type Default Description
api_token str, optional None User's Neptune API token. If None, the value of the NEPTUNE_API_TOKEN environment variable is used.

⚠ To keep your token secure, avoid placing it in the source code. Instead, save it as an environment variable.

project str, optional None Name of a project in the form workspace-name/project-name. If None, the value of the NEPTUNE_PROJECT environment variable is used.
**neptune_run_kwargs str, optional - Additional keyword arguments to be passed directly to the init_run() function, such as description and tags.


If you have your Neptune credentials saved as environment variables, the following starts the Neptune logger with default settings:

from ignite.contrib.handlers.neptune_logger import *

neptune_logger = NeptuneLogger()


You can also pass more options to the run created by the logger:

neptune_logger = NeptuneLogger(
    project="workspace-name/project-name", # (1)!
    name="My first Ignite run",
    description="Quick training run with Ignite",
    tags=["training", "low LR"],
  1. The full project name. For example, "ml-team/classification".

    To find the required string in the Neptune app, click How to create a new run. You can copy the project argument from the modal that opens.

To log metadata to the Neptune run, access the neptune_logger.experiment attribute. You can then use any logging methods from the Neptune client library to track your metadata, such as append(), assign() (=), and upload().

metadata = ...
neptune_logger.experiment["your/metadata/structure"] = metadata


Handler that saves an input checkpoint to the Neptune server.

Windows note

NeptuneSaver is currently not supported on Windows.


Name Type Default Description
neptune_logger NeptuneLogger - An instance of the NeptuneLogger class.


Set up the logger:

from ignite.contrib.handlers.neptune_logger import *

neptune_logger = NeptuneLogger()
evaluator = create_supervised_evaluator(model, metrics=metrics, ...)

def score_function(engine):
    return engine.state.metrics["accuracy"]

to_save = {"model": model}

Pass the Neptune logger to the saver:

from ignite.handlers import Checkpoint

handler = Checkpoint(
    NeptuneSaver(neptune_logger), n_saved=2,
    filename_prefix="best", score_function=score_function,
evaluator.add_event_handler(Events.COMPLETED, handler)

Close the logger when done:


You can access example checkpoints and download them from this example run.

See also

NeptuneLogger reference in Ignite API docs