Elasticsearch

Building on it: what may you do?

Short answers based on the licence, for the version in the catalog.

• B1 Change the code for internal use in your company Yes, with conditions Yes, but if staff or others reach it over a network they must be able to get your modified source.
• B2 Build your own product or service on top and offer it to customers as SaaS Yes, with conditions Yes, but you must share your changes with the users (AGPL).
• B3 Make a closed-source derivative and sell or distribute it No No. The derivative must carry the same licence and the source must be offered.
• B4 Use the project's name and trademark No No, not without permission. The licence covers the code, not the name or logo.

Keep in mind

• Open core: parts of the project (often an ee/ or enterprise folder) are under a separate commercial licence and may not be changed or used freely.
• Contributing back to the project requires signing a Contributor License Agreement (CLA).
• Dual licensing: the vendor also sells a commercial licence if the terms above don't suit you.
• There is a licence note for this product (e.g. parts under another licence or version-specific terms): read it and check the licence of the exact version you use.

This is guidance, not legal advice. Check with a lawyer before deciding.