Graphiti is free and open source. It's MCP server works with any MCP client, from Cursor to Claude, too...

Graphiti MCP has tens of thousands of users. They deploy it to their desktops, servers, you name it. And for many different use cases: B2B, B2C, and personal use.

More here: https://github.com/getzep/graphiti

Source: me, one of the authors of Graphiti :-)