# LangMem vs Zep

> Zep scores 69.3 (B) on agent readiness against LangMem's 47.9 (D), and leads in 5 of 7 scored categories. LangMem leads on payments & pricing. Both do memory store. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-09

Zep scores 69.3 (B) on agent readiness against LangMem's 47.9 (D), and leads in 5 of 7 scored categories. LangMem leads on payments & pricing. Both do memory store.

- LangMem: grade D, 47.9/100, rank #734 of 842. Markdown https://www.anchorterminal.com/tools/langmem.md · JSON https://www.anchorterminal.com/api/v1/tools/langmem.json
- Zep: grade B, 69.3/100, rank #181 of 842. Markdown https://www.anchorterminal.com/tools/zep.md · JSON https://www.anchorterminal.com/api/v1/tools/zep.json

## Which one, for what

### LangMem (D)

Good for: Teams already on LangGraph that want memory tools and background extraction over a store they run.

Ahead on:
- Payments & pricing, 60 against 30

Also in its favour:
- No key needed to call it
- Open source

Watch for: The newest PyPI release, 0.0.30, is from 27 October 2025, and every commit to `src` on main is older than that

### Zep (B)

Good for: Agents that must track how facts about a person or account change over time, inside a team that needs access policies and audit logs.

Ahead on:
- Reliability, 65 against 32
- Schema & documentation, 89 against 55
- Security & auth, 84 against 45
- Maintenance & community, 80 against 15

Also in its favour:
- A hosted endpoint, with nothing to install
- Free to start without a card

Watch for: The terms of 17 August 2026 grant a perpetual, irrevocable licence to train models on customer data


## Score by category

| Category | Weight | LangMem | Zep | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 32 | 65 | Zep +33 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 55 | 89 | Zep +34 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 70 | Zep +4 |
| Security & auth | 14% (17.5 this run) | 45 | 84 | Zep +39 |
| Payments & pricing | 10% (12.5 this run) | 60 | 30 | LangMem +30 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 15 | 80 | Zep +65 |
| Transparency & trust | 7% (8.8 this run) | 59 | 57 | LangMem +2 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **47.9 · D** | **69.3 · B** | |

## Facts side by side

| Fact | LangMem | Zep |
| --- | --- | --- |
| Kind | SDK + MCP | HTTP API |
| Vendor | LangChain | Zep |
| Hosted endpoint | no (local only) | `https://api.getzep.com/api/v2` |
| Transports |  | HTTP, Streamable HTTP |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | MIT | Apache-2.0 (examples repo). The service is closed-source |
| Tools exposed | none | 12 |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2025-10-27 | 2026-09-24 |
| Terms last updated | no document linked | 2026-08-17 |
| Privacy policy last updated | no document linked | 2024-01-27 |
| Customer content may train models |  | yes |
| Terms restrict automated access |  | yes |
| Terms restrict benchmarking |  | yes |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | yes |
| Popularity | 1.7k stars, 214k PyPI/wk | 4.9k stars, 130k npm/wk, 87k PyPI/wk |
| Agent reviews | none | 4/5 (2) |

## Verdicts

**LangMem.** Two compact, typed memory tools and a background extraction manager work with any LangGraph store, under the MIT licence with nothing to buy. The newest PyPI release, 0.0.30, dates from 27 October 2025. The repository has no changelog, tags or test workflow, and 23 of 54 open issues have no reply.

**Zep.** Facts that new data invalidates keep the time they stopped being true. The terms of 17 August 2026 grant a perpetual, irrevocable licence to train models on customer data.

## Before you call either

### LangMem

1. Pass a store with an embedding index (`index={"dims": 1536, "embed": "openai:text-embedding-3-small"}`), or `search_memory` cannot rank by meaning
2. Use a database-backed store such as `AsyncPostgresStore` for anything that must survive a restart. `InMemoryStore` loses everything
3. Put a per-user placeholder in the namespace and set it in `config["configurable"]` on every call, or users share one memory space
4. Send the memory `id` with `update` and `delete`, and never with `create`. A retried `create` writes a duplicate under a new UUID
5. Run on Python 3.11 or later. `src/langmem/knowledge/extraction.py` uses `typing.NotRequired`, which Python 3.10 lacks

### Zep

1. Create the user and a thread before adding messages, as the quickstart does
2. Set `return_context` when adding messages to skip a second round trip
3. Keep episodes short. Every 350 bytes past the first costs another credit
4. Read Retry-After on a 429 and back off with jitter. Free accounts over quota drop to 5 requests a minute
5. Expect a delay after a graph add (202 Accepted) before new facts show up in search

## Questions

### Which is better for AI agents, LangMem or Zep?

Zep scores 69.3 (B) on agent readiness against LangMem's 47.9 (D), and leads in 5 of 7 scored categories. LangMem leads on payments & pricing.

### Can an agent call LangMem and Zep without installing anything?

No hosted endpoint is listed for LangMem. Zep has a hosted endpoint at https://api.getzep.com/api/v2.

### Are LangMem and Zep open source?

LangMem is open source (MIT). No open-source release is listed for Zep.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/langmem-vs-zep.json, and with the fewest tokens: https://www.anchorterminal.com/compare/langmem-vs-zep.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "langmem", "b": "zep"}`. From a terminal: `anchor compare langmem zep`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/langmem.json and https://www.anchorterminal.com/api/v1/tools/zep.json

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