From the Developer Portal
From the AYLIEN.com

Frequently Asked Questions

Do you offer a free plan?
Yes, you can register for the free plan here.
How and when can I upgrade my plan?
You can upgrade your plan at any time. To upgrade your plan access the developer portal, navigate to plan, and choose which plan you wish to upgrade to. Please note that you can only change plans once you’ve entered your payment details.
Does the access to various features differ from plan to plan?
No, all Text Analysis features are available in every plan.
How do you define a hit?
A hit is counted as performing one analysis on one document (article, tweet, or any other piece of text). For example, extracting entities and summarizing an article counts as two hits.
Do you provide an on-premise solutions?
Yes we do, contact our sales team to hear more about our on-premise solutions.
What if I need to make more hits than are offered in the Growth plan?
We have an unlimited plan available. The “Enterprise” plan comes as part of our on-premise solutions. Get in touch to find out more.
Is there a limit on how many hits I can make?
Yes, each plan has a limit on the total number of hits that can be made on a monthly basis. Please refer to our plans list above for more information on limits. If you’re having trouble choosing an appropriate plan, get in touch here.
How frequently can I call the API?
Each plan has its own per minute rate limits. Please refer to the plans list above for these limits.
What happens if I make more hits than allowed in my plan?
You will receive a “403 Authentication failed” response if you go beyond your plan’s cap limit.
Do you provide academic pricing?
Yes, we provide discounted packages for approved researchers and academic institutions. Get in touch to find out more.