These tools competes with

LettavsEverOS

Stateful agents with long-term memory — formerly MemGPT versus Local-first, markdown-native memory runtime for agents

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Choose Letta when…

  • •need agents with persistent cross-session memory
  • •context window length is limiting your application
  • •building personal assistants or long-running agents

Choose EverOS when…

  • •You want agent memory stored as plain, human-readable markdown files
  • •You need local-first memory with no hosted service dependency
  • •You want hybrid keyword + vector retrieval out of the box

Side-by-side comparison

Field
Letta
EverOS
Category
Memory & Persistence
Memory & Persistence
Type
Open Source
Open Source
Free Tier
✓ Yes
✓ Yes
Pricing Plans
Open Source: FreeCloud: $20/mo
OSS: Free
GitHub Stars
⭐ 13,200
⭐ 11,500
Health
●100 — Active
●100 — Active

Letta

Letta (formerly MemGPT) is an open-source framework for building stateful AI agents with persistent, editable memory. Agents remember conversations across sessions, search their own memory, and update their knowledge over time — solving context window limitations.

Website ↗GitHub ↗

EverOS

Open-source agent memory runtime storing state as plain markdown with hybrid BM25 + vector retrieval, plus 'self-evolving' skills that update from experience. Local-first alternative to hosted memory layers like Mem0 and Letta.

Website ↗GitHub ↗

Only Letta (3)

LangGraphOpenAI APIEverOS

Only EverOS (2)

Mem0Letta

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