AI memory tools, compared

Every figure read on the vendor's own site or repository on 22 September 2026

“Memory for your AI” now describes a dozen products that don't really compete on the same axis. Most are libraries or local servers you run yourself. A few, including Pryzm Memory, are hosted services your assistant connects to over the network. That single difference decides more than any feature list.

Below is what we could verify, product by product. Where a vendor makes a claim we cannot independently check — certifications, encryption details, data residency — we say so instead of repeating it as fact. Prices move: follow the link before you decide.

The table

ProductRemote MCPHostingLicenceRetrievalEntry pricing
Pryzm MemoryYes — OAuth 2.0, hosted endpointManaged cloud onlyProprietaryhybrid RRF + cross-encoder rerankFree (100 memories) · €9,99 · €19
Mem0Yes — mcp.mem0.aiCloud + self-hostApache 2.0Vector + keyword + rerank, graph on ProFree tier · $19 · $249
SupermemoryYes — mcp.supermemory.aiCloud + self-hostMITSemantic + hybrid, vector-graphFree tier · $19 · $100 · $399
HindsightYes — one endpoint per bankSelf-host + cloudMITVector + BM25 + graph + temporalSelf-host free · cloud usage-based
basic-memoryCloud plans onlySelf-host + cloudAGPL-3.0Full-text + Vector, optional rerankSelf-host free · $15/seat · $30/seat
claude-memCloud plans onlyLocal-first + cloudApache 2.0SQLite FTS5 + VectorEngine free · $20 · $333/seat
mcp-memory-serviceYes — OAuth 2.0 (self-run)Self-host / localApache 2.0Local vector + BM25Free
Knowledge Graph Memory ServerNo — stdio, local onlyLocal fileOpen sourceSubstring match, no vectorsFree

Pricing is the publicly listed entry ladder. Pryzm is priced in euros, everyone else in US dollars — nothing is converted. Usage-based plans cannot honestly be reduced to a monthly figure, so they are labelled as such.

Remote MCP versus local-only

The official Knowledge Graph Memory Server writes to a JSONL file on your machine and speaks stdio. It is free, dependable, and completely invisible to Claude on your phone, to ChatGPT, or to any browser-based client. The same is true in practice of mcp-memory-service unless you deploy and expose it yourself — it does support OAuth 2.0 with dynamic client registration, which is the right design, but you are the one operating it.

Pryzm Memory, Mem0 and Supermemory all publish a hosted MCP endpoint with OAuth sign-in, so the same memory follows you from client to client with nothing installed. Hindsight exposes an MCP endpoint too, but you host it. basic-memory and claude-mem are local-first, with remote access reserved for their paid cloud tiers.

Where the data physically lives

Pryzm runs on Hetzner in Germany, under EU jurisdiction, with full-disk encryption at rest and one PostgreSQL schema and role per tenant, enforced by the database rather than by application code. We argue about this part publicly because it is checkable.

For Mem0 and Supermemory we could confirm that GDPR compliance is claimed, and for Mem0 also SOC 2 Type 1 and HIPAA. What we could not confirm for either, from public pages, is the hosting region or an EU data-residency option. The self-hostable tools sidestep the question entirely: the answer is wherever you put them — which, for a lot of people, is the right answer.

Retrieval

A memory you cannot retrieve is storage. Pryzm combines lexical and vector search with reciprocal rank fusion, then re-scores the candidates with a multilingual cross-encoder, on top of multilingual embeddings and an HNSW index — eight languages, tuned for French as well as English. Mem0, Supermemory, Hindsight, basic-memory and claude-mem all run some form of hybrid search; Hindsight and Mem0 add a graph layer for multi-hop questions, which Pryzm does not have. The official reference server does substring matching and no vector search at all.

Where Pryzm is the wrong choice

You want to read or fork the source. Pryzm's engine is not open source. Mem0 (Apache 2.0), Supermemory (MIT), Hindsight (MIT), claude-mem (Apache 2.0) and basic-memory (AGPL-3.0) all are.

You need to self-host or run air-gapped. We don't ship a self-hosted build today. Almost everything else on this page does.

You want zero-knowledge encryption. Nobody here offers it, us included. Our sealed mode is announced, not shipped, and we label it that way. Technical administrative access to the servers exists, is restricted, and is logged.

You want graph traversal. Hindsight and Mem0 Pro do multi-hop entity and temporal graphs. We do ranked retrieval, well.

Method and sources

Facts were collected on 22 September 2026 from each vendor's pricing page, documentation and GitHub repository, and cross-checked against the GitHub API for licence and activity. Each product name in the table links to its source. GitHub star counts are deliberately left out: they move weekly and measure attention, not fitness. OpenMemory is left out too — it was removed from the Mem0 monorepo in July 2026 and we could not establish the status of any successor, so we make no claim either way.

Something out of date or wrong about your product? Write to contact@pryzm-memory.com and we will correct this page.

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