MEMORY: topology — graph edges + contradiction detection

[Hmbown]

Part of #534 (Phase 3 EPIC). Builds on #535 (substrate) and #536 (engine).

Thesis

Memories don't live alone — they cause, supersede, contradict, support each other. Storing edges turns "recall" into "navigate from this fact to its consequences" and lets the system flag when a new memory contradicts an old one instead of silently piling up conflicts. Silent conflict accumulation is the #1 source of "memory feels wrong" failures in long-lived stores.

Edge kinds

Kind	Meaning
causes	A led to B happening
supersedes	B replaces A; A should not surface in recall unless asked
contradicts	A and B make incompatible claims; needs resolution
supports	B is evidence for A
promoted_from	B graduated from A (episodic → procedural, etc., for #F lifecycle)

Concrete

• Edge table in the SQLite store (memory_edges with from_id, to_id, kind, created_at).
• Recall returns related memories with their relationship (1-hop traversal default, configurable depth).
• Contradiction detection: when a new semantic or constitutional memory is written, run a gated LLM check against existing memories tagged with overlapping keys. If a conflict is detected, surface to the user via /memory UI: "this fact contradicts X — supersede, keep both, or drop new?"
• Contradiction LLM check is opt-in (cost) and uses the cheapest available model.

Open questions

• How wide should the contradiction-check candidate set be? FTS5-overlap top-N? Same-type same-scope?
• Should contradiction checks run inline (block the write) or async (write first, surface conflict next session)?
• UI: how to render an edge graph in a TUI without becoming visual noise — list view of related memories per hit, or actual graph rendering?

Acceptance signals

• Edges queryable from recall results.
• Contradictions prompt the user, never auto-resolve.
• Edge graph survives session and migration.
• supersedes edges suppress superseded memories from default recall (visible only with --include-superseded).

[merchloubna70-dot]

mem0 already implements the core of this issue:

• Graph edges (causes / supersedes / contradicts / supports): supported via Neo4j sidecar — search_graph and get_entity MCP tools expose the graph
• Contradiction detection: built into mem0's LLM-driven ingest loop — when a new memory conflicts with an existing one, it auto-issues a DELETE for the stale record. There's no separate "present conflict to user" UI, but that's a thin Rust layer on top of the MCP event stream

Running Neo4j locally adds overhead, but it's optional — the vector-only mode still gives contradiction detection without graph traversal.

Full proposal with ready-to-use mcp.json config in #534. This could close most of the graph topology work without any Rust implementation.

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wangfengcsu@qq.com