memlens Tracks Down Memory Retrieval Failures

Feisty_Dog_1198 · reddit · 2026-07-15

The author built a tool called memlens specifically designed to track down why an AI agent's memory retrieval "failed to recall."

The Problem Solved

Existing memory tools usually only return the final relevant results.
But during actual debugging, the more critical questions are:
Was it never stored in the first place?
Was the score too low?
Was it silently filtered out by a threshold?

How memlens Works

It doesn't handle retrieval itself; instead, it wraps a trace layer that logs the complete scoring and retention reasons for every candidate memory.
It currently supports two adapters:
mnemos: Natively exposes the true score of each candidate.
mem0: Bypasses the public API's hidden thresholds to fetch all candidates first, then reapplies thresholds based on the actual logic to reveal the filtered-out candidates.
It also provides a terminal viewer, memlens view trace.json, for easy trace inspection.

The author explicitly positions it as a debugging layer to "observe the true scoring process," rather than just another retriever that fabricates scores.

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memlens Tracks Down Memory Retrieval Failures

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