is it really FOSS?

Mastra

TypeScript AI agent framework

Nope!
It's not FOSS, and it doesn't currently claim to be, although it may have been in the past.

Details

The project is provided under an Elastic License which is non-FOSS as it sets limits upon use and modification.

The project advertises as open source in its docs, marketing.

This was queried on HackerNews, with this said in the response:

We’re using Elastic v2 for now because we want users to be able to do anything with us, but protect from eg AWS

But the license goes beyond just stopping AWS, and still isn’t open source.

The license was touched upon in a GitHub issue, with a member of the project providing a response which doesn’t really align with their license terms.

The project appears to have raised $500k in funding from YC. There’s little information about other revenue streams, although there is a sign-up for a “Mastra Cloud”, indicator a likely hosted service offering.

Details last reviewed 2025-06-11. Mistakes or outdated information? Let us know by opening an issue on Codeberg.