01At a glance
Mem0 is a memory layer: your application sends it messages, a model distils them into facts, and queries get the nearest facts back. recall is a reader: it opens the transcripts Claude Code, Codex and Cursor already keep, indexes them without a model, and writes a few markdown notes a night from them.
Both give an agent long-term memory. One is a service you integrate; the other is a tool you install.