# Licensing FAQ #### How much does the Chat SDK cost? The Chat SDK is free and open source. The SDK is released under the [Apache 2.0](https://tldrlegal.com/license/apache-license-2.0-\(apache-2.0\)) license with the “Commons Clause” License Condition v1.0. That provides all the freedom of the Apache license while adding a clause that would prevent big cloud companies from monetizing the project. #### So if you give the code away for free, what's in it for you? We offer [consulting services](https://chatsdk.co/pricing/) and [premium addons](https://chatsdk.co/modules-2/) for the Chat SDK. The add-ons include things like: typing indicators, read receipts, video and audio messages etc... We give 90% of the chat functionality away for free and our customers are free to develop this functionality themselves if they wish. However, for a small licensing fee they can get robust well tested addons instantly. #### Will the Chat SDK always be free and open source? If so, how long will it be supported? The core Chat SDK will always be free and open source. We are planning to support the code until at least December 2022. #### I want you to customize the code for me. How much will it cost? We have a team ready to help you add the features you need. If you send us an email at we will help you define a specification and then we'll provide a quote for the work. #### How many users can Chat SDK support? We have tested the Chat SDK with 300,000 daily users and it works perfectly. That's with over 2 million monthly users! Really, Firebase is the only limitation in terms of scaling and Firebase can support millions of daily users. #### What's the Firebase database schema? Firebase uses a no-SQL database so it doesn't have a predefined schema. As the app runs, it will generate the schema as it goes. The schema is very flexible - you can add extra custom data if you like. As long as you don't remove fields, the Chat SDK will run correctly. If you're interested in the schema you can check out the [Firebase Schema Guide](https://github.com/chat-sdk/chat-sdk-ios/wiki/Understanding-the-Chat-SDK-data-schema). #### If the client defines the schema, how is the data secured? Firebase includes a set of flexible security rules that help to secure the data. You can read more on the [Firebase website](https://firebase.google.com/docs/database/security/) and by looking at the [rules.json](https://github.com/chat-sdk/chat-sdk-ios/blob/master/rules.json) file. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://chat-sdk.gitbook.io/chat-sdk/commercial/licensing-faq.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.