Wandb provides an API to give users direct access to wandb's database. This can be useful for automated systems to asynchronously add extra data to a completed run or to export data for custom analysis. For complete documentation refer to our API Reference.


Before using the API you need to store your key locally by running wandb login or set the WANDB_API_KEY environment variable.

Querying Runs

The most common use of wandb's API is to export data from a past or running run.

This can be used for ad-hoc data analysis or taking action in automated environments using custom logic.

import wandb
api = wandb.Api()
run = api.run("<entity>/<project>/<run_id>")

The most commonly used attributes of a run object are:




A dictionary meant to store inputs to the model such as hyperparameters.


A dictionary of outputs which can contain everything from scalars such as accuracy or loss to large files. The command wandb.log() updates this obejct. It can also be set directly.


A list of dictionaries meant to store values that change while the model is training such as loss. The command wandb.log() appends to this object.

You can also modify or update the data of past runs.

By default a single instance of an api object will cache all network requests. If your use case requires real time information in a running script, call api.flush() to get updated values.

Querying Multiple Runs

The W&B API also provides a way for you to query across runs in a project with api.runs(). The most common use case is exporting runs data for custom analysis. The query interface is the same as the one MongoDB uses.

runs = api.runs("username/project", {"$or": [{"config.experiment_name": "foo"}, {"config.experiment_name": "bar"}]})
print("Found %i" % len(runs))

Calling api.runs(...) returns a Runs object that is iterable and acts like a list. The object loads 50 runs at a time in sequence as required, you can change the number loaded per page with the per_page keyword argument.

api.runs(...) also accepts an order keyword argument. The default order is -created_at, specify +created_at to get results in ascending order. You can also sort by config or summary values i.e. summary.val_acc or config.experiment_name

Error Handling

If errors occur while talking to W&B servers a wandb.CommError will be raised. The original exception can be introspected via the exc attribute.

'Git' state of a run through the API

You can see the git commit through the UI under the information tab. It is also available by the files api, stored in: "wandb-metadata.json" so you can use the public api to grab that file then parse the json file.