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Zep vs Letta. Rows marked Differs have different values.

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Zep

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Startup

Letta

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TypeStartupStartup
CategoriesDiffers
In one lineLong-term memory for agents, built on temporal knowledge graphs.Stateful agents with memory, from the team behind MemGPT.
Stage & fundingDiffers—Seed · $10M seed led by Felicis (2024)
GitHub stars——
License——
Language——
Last push——
Works with——
Built on——
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Similar toDiffers
People linkedDiffers12
Events00
Pros
  • MetadataBuilt on Graphiti, its Apache-2.0 temporal knowledge-graph engine with about 32k stars, which supports Neo4j, FalkorDB and Amazon Neptune.[1]
  • DocsCredits are charged only for ingested Episodes; retrieval, storage, users and threads cost 0 credits.[1]
  • DocsEnterprise offers SOC 2 Type II, a HIPAA BAA, bring-your-own-key encryption and bring-your-own-cloud deployment in your VPC.[1]
  • DocsThe free trial tier includes 10,000 credits per month for prototyping.[1]
  • User reportsIts MemGPT-style memory helps with long-running work: one HN user says it made long-context documentation manageable.[1]
  • MetadataApache-2.0, self-hostable and popular (about 25.3k GitHub stars). The ADE lets you inspect and edit an agent's memory blocks while it runs.[1][2]
  • DocsLetta Code brings its learning memory into a coding-agent harness, with headless and --yolo modes for sandboxes (per Letta staff on HN).[1][2]
  • User reportsOne engineering manager said they would rather build on Letta or Mastra than trust newer personal-agent projects.[1]
Cons
  • DocsZep Community Edition was deprecated and moved to a legacy folder with no updates, so the full Zep service is now available only as cloud or BYOC.[1][2]
  • DocsPaid self-serve starts at $125/month (Flex), while SOC 2 Type II, the HIPAA BAA and audit logs are listed as Enterprise-only.[1]
  • DocsGraphiti needs an LLM with reliable structured output, and its README warns that other services may cause ingestion failures, especially with smaller models.[1]
  • User reportsThe Mem0/Zep LoCoMo dispute leaves neither vendor's headline benchmark score directly comparable.[1]
  • Independent testAn independent review says to avoid it for stateless apps or when the main problem is coordinating several agents, because it focuses on memory for a single agent.[1]
  • User reportsMemory extraction that runs on an LLM gets expensive at scale; a competitor estimates $1k-3k per month in API calls at 100K memories a month.[1]
  • User reportsA builder who tried it found that memory architectures like Letta's 'simply move the pain to retrieval'.[1]
Best forAgents that need temporally aware, graph-structured memory with enterprise compliance.Builders of long-lived, stateful single agents who want memory they can inspect and edit, and can self-host.
Watch out forIf you need fully self-hosted memory, plan to build on Graphiti yourself.Budget for the extra LLM calls that memory management makes, and check retrieval quality on your own data.
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