A CLAUDE.md (or AGENTS.md, etc) is typically hand-written, untyped, and never checked. Nothing stops it from still telling the agent to do something you reversed six months ago, and nobody validates it in CI.

Lore keeps the actual decisions/requirements/designs as typed Markdown in your repo, and rac export --agent-rules generates those rules files from the decisions that are currently Accepted — superseded ones drop out automatically. So the rules file becomes a build artifact of your knowledge base instead of something you hand-maintain and hope stays current. (Note that in dogfooding Lore that its repo does exactly that: its CLAUDE.md is a ~20-line router into the validated corpus)

The part that makes it more than markdown-with-a-schema is write-time enforcement. rac validate / rac gate run in CI and fail the merge if an artifact is malformed, a link is broken or ambiguous, or anything points at a superseded decision. At serve time it's a read-only MCP server doing deterministic retrieval — the exact current decision by ID, not similarity-ranked guesses. No RAG, no embeddings, no model call to decide what's relevant.

On spec-driven dev (Spec Kit, OpenSpec, Kiro): those drive a change — proposal → design → tasks → implementation, usually archived when the feature ships. Lore holds the durable why that outlives any single change and gets served to the agent on every session. It's the layer above SDD, not a replacement — you'd point a spec tool at the decisions Lore is enforcing.