Universal Memory Protocol is a new open spec built on a tidy analogy: MCP standardised how agents call tools, A2A standardised how they talk to each other, but nothing standardises how they remember. Every harness reinvents memory privately, so knowledge accumulated in Claude project notes, Obsidian folders, vector stores and SQLite files dies at each vendor boundary. UMP proposes one portable record format and a small operation set, remember and recall, so a new agent or store can extend existing memory rather than start from zero.
The design detail that stands out is trust plumbing: records are signed and bi-temporal, carrying provenance about who created each memory and how, with scoping by owner, project and visibility. Distribution is pragmatic too. It ships as an npx-installable MCP server for Claude Code, Codex or Cursor, a TypeScript SDK, and a plain HTTP interface for everything else.
The catch is the same one every standard faces. MCP spread because Anthropic shipped it into every harness that mattered; a community spec has to win adoption one integration at a time.