Archived release, published August 3, 2026. The current index is v0.2.
Which memory should your AI agent use?
Compare independent test results to see where each memory system works well and where it fails.
Agentic Memory Indexi
Agentic Memory Index v0.1 · Aug 2026
Highlights
Accuracy, cost, and speed for every tool, measured the same way.
Agentic Memory Indexi
The overall score: how often each tool finds the right answer.
Costi
USD per 1,000 successful answers
Answer speedi
How long an answer takes end to end, same agent model on every tool.
Check your own agent memory
Tell us which memory system you build or use and we’ll show you what the overall score doesn’t tell you.
Which memory tool is right for your agents?
No tool wins everything: match each tool's strengths to the questions your agents actually ask.
Correct Answers by Task Typei
From direct recall to synthesis, each tool has its strengths.
Karpathy Wiki
Mitosis Cortex
gbrain
Mem0
Hyperspell
Anthropic Memory
Zep
Supermemory
Failure Attributioni
Know how each tool tends to fail before your agent depends on it.
Karpathy Wiki
Mitosis Cortex
Mem0
Zep
gbrain
Hyperspell
Anthropic Memory
Supermemory
Rankings and retention
Every tool's score, and whether what it stores survives.
Every tool's score, cost, and speed in one table.
| # | Service | Index ↓ | Cost / 1k | Lookups / sessionLookups |
|---|---|---|---|---|
| 1 | Karpathy Wiki |
98.5 | $568.93 | 1.6 |
| 2 | Mitosis Cortex |
96.9 | $418.40 | 5.1 |
| 3 | gbrain |
92.9 | $471.40 | 5.3 |
| 4 | Hyperspell |
92.4 | $429.71 | 6.8 |
| 5 | Mem0 |
92.3 | $341.42 | 5.1 |
| 6 | Anthropic Memory |
84.0 | $419.45 | 8.4 |
| 7 | Supermemory |
77.1 | $519.04 | 5.7 |
| 8 | Zep |
75.1 | $394.75 | 5.1 |
| — | Claude Code built-in memoryClaude Code memory | 67.7 | $426.90 | — |
Long-term retentioni
How well early facts survive: probed at five checkpoints across 56 working sessions.
Speed
One-time setup, indexing lag, and per-operation latency.
Onboarding, readiness, and store-session times for every tool.
| Tool | Onboard ↑ | Time to ready | Time to store |
|---|---|---|---|
| Anthropic Memory |
0.8 min | local | 56.0s |
| Karpathy Wiki |
1.0 min | local | 62.0s |
| Supermemory |
1.6 min | 4.6s | 57.0s |
| Mem0 |
1.9 min | 2.7s | 41.0s |
| Hyperspell |
3.1 min | 16.0s | 41.0s |
| gbrain |
3.2 min | local | 99.0s |
| Mitosis Cortex |
7.5 min | 0.40s | 55.0s |
| Zep |
9.1 min | 21.3s | 41.0s |
| Claude Code built-in memoryClaude Code memory | — | local | 25.0s |
Where retrieval time goesi
The average answer, second by second.
Karpathy Wiki
Zep
Mitosis Cortex
Mem0
Supermemory
Hyperspell
Anthropic Memory
gbrain
Pricing and cost
What the tools charge, and what successful answers actually cost.
What each tool costs to start, from list pricing.
| Tool | Free tier | Starting at | Open source |
|---|---|---|---|
| Karpathy Wiki |
Always | $0 | Open method |
| Mitosis Cortex |
7-day trial | $7.99/mo | Closed |
| gbrain |
Pay for embeddings | $0 | Yes |
| Hyperspell |
No cap hit at 200+ | Not Listed | Closed |
| Mem0 |
~550 answers/mo | $19/mo | Core is |
| Anthropic Memory |
Always | $0 | Yes |
| Supermemory |
~800 answers/mo | $19/mo | Yes |
| Zep |
~950 answers/mo | $125/mo | Engine (Graphiti) is |
| Claude Code built-in memoryClaude Code memory | Included with Claude Code | $0 | Bundled |
List prices as of Jul 27, 2026.
Cost Breakdowni
Per 1,000 successful answers: agent token spend, the entry paid tier amortized at its capacity, and embeddings where billed separately.
Mem0
Zep
Mitosis Cortex
Anthropic Memory
Hyperspell
gbrain
Supermemory
Karpathy Wiki