Leadfeeder has a 'Read Only' API available for Premium subscribers.
You can find Leadfeeder API documentation here.
Your personal Leadfeeder API key is available in your personal settings under API. Alternative access it via this link https://app.leadfeeder.com/settings/api.
You'll need the API key when querying data from Leadfeeder Public API.
Read here the most common use cases we’ve noticed that are helpful to our customers’ success.