Choosing an AI memory layer in 2026? Here's what the docs don't tell you.
The AI memory market has consolidated around three serious players: Mem0, Zep/Graphiti, and Mnemonic. Each solves a different core problem. The pitch decks and docs won't tell you which one is actually right for your use case — especially if compliance is in the picture.
This post is the comparison we wish existed when we were evaluating. No fluff, no undisclosed affiliations, no cherry-picked benchmarks. Just what each tool actually does well and where it breaks down.
The quick answer
- Mem0 — best ecosystem, fastest onboarding, no governance
- Zep — best temporal reasoning, deprecated free tier, no governance
- Mnemonic — governed memory, compliance-first architecture, best pricing for graph features
Feature comparison table
| Feature | Mnemonic | Mem0 | Zep | |---------|----------|------|-----| | Graph memory | ✅ All tiers | ❌ $249/mo only | ✅ Cloud + Graphiti OSS | | Vector search | ✅ All tiers | ✅ All tiers | ✅ All tiers | | Retention policies | ✅ Configurable | ❌ Not a feature | ❌ Not a feature | | Audit logs | ✅ Every read/write/delete | ❌ None | ❌ None | | PII auto-redaction | ✅ Pre-storage | ❌ None | ❌ None | | Deletion workflows | ✅ Immutable proof | ❌ Manual | ❌ Manual | | Multi-tenant isolation | ✅ Architecture-level | ⚠️ Namespace-level | ⚠️ App-level | | Temporal/bi-temporal | ⚠️ Retention windows | ❌ No (overwrites) | ✅ Core feature | | SOC 2 Type II | 🚧 In progress | ✅ Late 2025 | ✅ Certified | | HIPAA BAA | 🚧 Enterprise (planned) | ✅ Enterprise | ✅ Enterprise | | Self-hosting | ❌ Managed only | ⚠️ Complex (auth required) | ⚠️ OSS only (no managed features) | | Free tier | ✅ Generous (500 memories) | ✅ 10K memories (vector only) | ⚠️ 1,000 credits (minimal) | | GitHub stars | — | ~52K | ~25K (Graphiti) | | Framework integrations | Growing | 21+ (AWS, LangChain, etc.) | MCP server, Claude/Cursor |
Pricing breakdown
Mnemonic
| Tier | Price | Memories | API Calls/mo | Notable | |------|-------|----------|-------------|---------| | Free | $0 | 500 | 1,000 | PII scanning, audit logs, 30-day retention | | Pro | $99/mo | 50,000 | 100,000 | Full governance engine, 1-year retention, multi-tenant | | Business | $349/mo | 500,000 | 1,000,000 | Custom retention policies, advanced audit exports, SSO | | Enterprise | Custom | Custom | Custom | BAA, custom data residency, on-prem/VPC |
Governance is included at every tier. Audit logs, PII redaction, and retention enforcement are not add-ons.
Mem0
| Tier | Price | Memories | Notable | |------|-------|----------|---------| | Free | $0 | 10,000 | Vector only — no graph features | | Standard | $19/mo | Higher limits | Vector only — still no graph | | Pro | $249/mo | Unlimited | Graph finally unlocked here | | Enterprise | Custom | Custom | SOC 2, HIPAA BAA, BYOK |
The graph paywall is the most-cited developer complaint about Mem0. Entity tracking, relationship modeling, and multi-hop queries are Pro-only. If you need graph memory, you're paying $249/mo — with no governance features included.
Zep
| Tier | Price | Notable | |------|-------|---------| | Free | $0 | 1,000 episode credits — disappears in real prototyping | | Flex | ~$8.50/1M input tokens | Usage-based, graph included | | Enterprise | Custom | SOC 2 Type II, HIPAA BAA, BYOK, VPC |
The free tier is effectively a demo. Community Edition was deprecated in April 2025 — self-hosting the full Zep stack now requires running Graphiti + a graph DB (Neo4j, FalkorDB, or Kuzu) yourself. The managed free tier runs out immediately in any real workflow.
The governance gap
This is the thing neither competitor talks about — because neither has solved it.
What "compliance" means for Mem0 and Zep: SOC 2 and HIPAA certifications. Badge on the pricing page. Enterprise-tier checkboxes.
What compliance actually requires in production:
- Retention policies: "Delete memories containing PHI after 90 days." Neither Mem0 nor Zep has this as a configurable product feature. It's your problem to implement.
- Audit log export: "Show me every time an agent accessed a patient's memory this quarter." Neither has a queryable, exportable audit trail for memory operations.
- Deletion workflows: "This user exercised their GDPR right to erasure — provide proof of deletion." Neither has a built-in workflow or immutable deletion record.
- PII classification: "Flag memories that contain PHI before they're stored." Neither has pre-storage PII detection.
- Access control beyond API keys: Both support API key scoping. Neither has per-memory access policies enforced at the infrastructure layer.
This is not a minor gap. Regulated industries — healthcare, fintech, HR tech, legal — cannot deploy AI memory with no retention controls, no audit trail, and no deletion mechanism. The governance gap is why Mnemonic exists.
Developer friction points
Mem0 frustrations (from GitHub, Reddit, HN)
1. Graph memory paywall at $249 The most-cited complaint. Developers build their memory architecture on Mem0 in the free tier, then discover the features they actually need (graph relationships, entity tracking, multi-hop reasoning) are locked behind a 13x price jump. No Pro discount for graph-only access.
2. Memory overwrites — no history "Mem0 overwrites, which loses history" — multiple Reddit threads. If a user's preference changes, the old value is gone. No bi-temporal model means no ability to answer "what did the agent know about this user last month?"
3. Production reliability at scale Scira AI publicly switched to a competitor citing "unbearable latency" and unreliable indexing at scale. Enterprise teams report the product "felt too fragile" in production.
4. CVE-2026-0994 A Protobuf exposure flagged in the managed platform. Enterprise security teams initiated formal evaluation processes as a result.
Zep frustrations (from GitHub, Reddit, community)
1. Community Edition deprecation April 2025: Zep deprecated free self-hosting. Significant community backlash. Teams that built workflows on Zep CE now have to pay for cloud or maintain a DIY Graphiti stack. "The initial thing that gave me concern was hiding the docs for local install."
2. Neo4j dependency overhead "Zep's bi-temporal approach is the right idea but comes with Neo4j as a dependency." Smaller teams find the operational overhead of running a graph DB in production unjustifiable for a memory layer.
3. Free tier too restrictive 1,000 episode credits disappears in any real prototyping workflow. There's no way to evaluate Zep seriously before hitting the paywall.
4. Python-first, TypeScript second Graphiti OSS is Python-only. TypeScript developers using Node.js are treated as second-class citizens in the open-source ecosystem.
When to choose each
We'll be honest here. Mnemonic is our product. We think it's the right choice for most teams building on AI in regulated environments. But it's not the right choice for everyone.
Choose Mem0 if:
- You're a startup or early-stage team that needs the fastest onboarding
- You're building a consumer product where governance is not a requirement
- You need ecosystem breadth — Mem0's 21 framework integrations and AWS Strands SDK partnership are unmatched
- You don't need graph memory (and $249/mo for graph is a dealbreaker)
- You have no compliance requirements and need memory working in under an hour
Mem0 wins: ecosystem, onboarding speed, community size (~52K GitHub stars)
Choose Zep if:
- Temporal reasoning is central to your use case — tracking how facts about entities change over time
- You need bi-temporal data (validity windows, superseded facts, factual lineage)
- Your team is comfortable with Python and graph DB operational overhead
- You're building research tooling or knowledge graph applications where Graphiti's design shines
Zep wins: temporal reasoning, bi-temporal modeling, academic/technical use cases
Choose Mnemonic if:
- You're building AI agents in a regulated environment (healthcare, fintech, HR tech, legal, insurance)
- You need retention policies that are enforced automatically, not manually
- You need an audit trail for memory operations — who read what, when
- You need GDPR/HIPAA-compatible deletion workflows with immutable proof
- You want graph memory without paying $249/mo for it
- Your InfoSec or legal team is involved in the evaluation
- You're a developer who got asked "how do we handle memory deletion requests?" by your compliance team and needs an actual answer
Mnemonic wins: governance, compliance architecture, pricing for graph features, regulated industries
The core architectural difference
Mem0 and Zep are memory-first products that added compliance certifications. Mnemonic is a governance-first product where memory is how the governance manifests.
The distinction is not philosophical — it shows up in the code.
With Mem0 or Zep, compliance is your implementation problem:
// Your responsibility: implement retention, redaction, audit logs, deletion proof await mem0.add(facts, { user_id: userId }); // ^ No TTL. No PII scan. No audit record. Nothing. With Mnemonic, governance is the infrastructure:
// Governance runs automatically: PII scan, TTL enforcement, audit log, access check await mnemonic.remember({ agent: 'intake-bot', tenant: 'acme-corp', fact: 'Patient prefers morning appointments.', retention: '90d', access: ['clinical-ops'] }); // ^ PII scanned before storage. TTL set. Audit record created. Access policy stored. For regulated industries, the second model is the one that survives an audit.
Bottom line
| Decision | Answer | |----------|--------| | Best for a hackathon | Mem0 | | Best for temporal/knowledge graph reasoning | Zep | | Best for governed memory in production | Mnemonic | | Best graph memory pricing | Mnemonic (Free/$99/$349 vs Mem0's $249) | | Most framework integrations | Mem0 | | Best for HIPAA/GDPR compliance architecture | Mnemonic |
Get started
Mnemonic's free tier includes 500 memories, audit logs, PII scanning, and 30-day retention — no credit card required.
See how governed memory works →