One Belief Per Fact: Building Agent Memory for Users Who Change Their Minds

Description and use

The agent memory system now stores a single current version per fact, preserves history, and flags conflicts, eliminating ambiguous responses when users change their minds.

Problem

Agent memory systems often store multiple contradictory facts per user, leading to ambiguous or conflicting responses when a user changes their mind across sessions.

Outcome

The system now returns a single, up‑to‑date belief per fact, with a clear version chain and conflict flag, eliminating ambiguous responses and enabling auditability.

Workflow

• 1. Capture raw episodic log after each session.
• 2. Asynchronously project log entries into typed, self‑contained fact sentences using an LLM.
• 3. Embed only the fact sentence text into a vector table; store metadata (key, version, provenance, flags) separately.
• 4. On write, fetch existing belief by stable key, compare new fact with LLM to decide SAME/UPDATE/CONFLICT.
• 5. For SAME: append session to provenance; for UPDATE: archive old, write new with current:true; for CONFLICT: archive old, write new with current:true, set contradiction flag.
• 6. On read, embed query sentence, perform vector search, filter results by current:true to surface the latest belief.
• 7. If a conflict flag is present, downstream agents can alert or handle accordingly.
• 8. Preserve history for audit and potential rollback.
• 9. (Future) Mark multi‑valued fact types to append rather than overwrite.

Evidence

The first cut of the semantic tier keyed facts by session. Every session inserted new rows, so after a handful of sessions there were six copies of Priya's risk tolerance, some of them contradicting each other, and no notion of "current."

Source

The update procedure is search-then-decide. When the projector extracts a new fact, it first fetches the existing belief under that key, then an LLM compares old against new and returns exactly one of three verdicts: SAME, UPDATE, CONFLICT.

Source

When a CONFLICT is detected, three things happen at once, and the design is deliberately not "silently overwrite."

Source