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MemPalace

Verbatim cross-session memory for LLMs — highest free LongMemEval score

PriceFree / Open Source (MIT). Self-hosted.Reviewed2026-04-21
Verdict — Ship
3 Ships1 Skips
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The Panel's Take

MemPalace is an open-source persistent memory system for LLMs that takes a philosophically different approach from every summarization-based alternative: it stores conversations verbatim, forever, and retrieves them with semantic precision. Where systems like MemGPT or standard RAG pipelines compress memories into lossy summaries, MemPalace treats exact wording as sacred — because often the specific phrasing of something a user said six months ago is the thing that matters. The storage architecture uses a hierarchical "memory palace" metaphor: people and projects are wings, topics are rooms, individual memories are drawers. Semantic retrieval is scoped to sub-trees rather than doing a flat vector search across everything, which dramatically reduces false positives and improves precision at depth. The system claims a 96.6% score on LongMemEval — the highest publicly reported score among free tools — and integrates with any OpenAI-compatible API endpoint. Verbatim storage does mean storage costs grow linearly with usage, and there's no built-in forgetting mechanism yet (which some see as a bug and others as a feature). But for personal assistants, coding agents, and any application where "you told me X last Tuesday" accuracy matters, MemPalace's approach to memory is architecturally more honest than the alternatives.

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MemPalace verdict: SHIP 🚀

3 ships · 1 skip from the expert panel

Full review: shiporskip.io/tool/mempalace-ai-persistent-memory-longmemeval-2026

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Ship · 7.5/10
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The reviews

The hierarchical tree-scoped retrieval is genuinely clever — instead of HNSW across your entire memory corpus, you're running a smaller, context-aware search. The OpenAI-compatible API means dropping this into an existing stack takes an afternoon. LongMemEval at 96.6% with free hosting is a compelling benchmark.

Helpful?

Verbatim storage with no forgetting is a liability problem waiting to happen — GDPR right-to-erasure, accidental PII retention, and storage costs that scale with time rather than importance. The LongMemEval benchmark was also designed by teams that use summarization; verbatim systems may be overfitted to it.

Helpful?

Persistent, accurate memory is one of the remaining gaps between AI assistants feeling like tools and feeling like collaborators. The verbatim approach is philosophically closer to how human memory actually works — not summaries, but specific episodic recall. MemPalace is pointing in the right direction.

Helpful?

For creative workflows, the difference between a summary of feedback and the exact words a client used is enormous. MemPalace's verbatim storage means your AI assistant can quote your art director's exact note from three months ago, not a paraphrase that lost the nuance. That's a real creative workflow upgrade.

Helpful?

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