Webhooks provide real-time updates about your prediction. Specify an endpoint when you create a prediction, and Replicate will send HTTP POST requests to that URL when the prediction is created, updated, and finished.

Here are some example scenarios where webhooks are useful:

• Persisting prediction data and files. Input and output (including any files) are automatically deleted after an hour for any predictions created through the API. Webhooks give you a way to receive all the metadata for a completed prediction, so you can store it in a database or save the output files to persistent storage before they're gone.
• Sending notifications when long-running predictions finish. Some predictions like training jobs can take several minutes to run. You can use a webhook handler to send a notification like an email or a Slack message when a prediction completes.
• Creating model pipelines. You can use webhooks to capture the output of one long-running prediction and pipe it into another model as input.

Note: Webhooks are handy, but they're not strictly necessary to use Replicate, and there are other ways to receive updates. You can also poll the predictions API or use server-sent events (SSEs) to check the status of a prediction over time.