Mem0

Mem0's MCP server gives Claude long-term memory that persists across conversations. It's built on Mem0's managed semantic memory service, which means you're storing context in the cloud rather than in local files or ephemeral session state. The big advantage over the official MCP memory server is user filtering — you can scope memories to specific users, which matters if you're building tools for multiple people or want to keep work and personal contexts separate. I'd reach for this when I'm working on a project that spans weeks and I want Claude to remember decisions, coding patterns, or domain knowledge without me repeating myself. For example, if you're iterating on a codebase with specific architectural constraints, Mem0 can recall those rules in future sessions. It's also useful for personal assistant workflows where you want Claude to remember your preferences, frequent tasks, or ongoing goals. The setup is straightforward — you need a Mem0 API key, which means signing up for their service. It's not self-hosted, so you're trusting a third party with your data. The semantic recall works well in practice: ask Claude to remember something, and it gets stored with enough context to retrieve it later when relevant. The user filtering is the killer feature here — you can namespace memories by user ID, which the official server doesn't support. Quirks: you're dependent on Mem0's uptime and API limits. If you're privacy-sensitive or working with proprietary code, storing context in a third-party service might not fly. Also, the repo doesn't include a package manager install, so you're cloning and configuring manually. It's not a dealbreaker, but it's an extra step compared to npm-installable servers. Skip this if you're happy with Claude's native memory features or if you need everything local. But if you're building multi-user tools or want persistent memory without rolling your own storage layer, this is the cleanest option I've found.