AgentIndex icon
AgentIndex
letta logo
letta
★ 25.2k
vs
Yggdrasil logo
Yggdrasil
★ 22

letta vs Yggdrasil

letta: Letta is a powerful platform for building stateful AI agents equipped with advanced memory, enabling them to learn and self-improve over time. It provides both a command-line interface for local agent execution and a comprehensive API with Python and TypeScript SDKs for seamless integration into applications.; Yggdrasil: Yggdrasil provides a local, always-on memory for AI agents like Claude Code and Codex, allowing them to retain project context, decisions, and lessons across different sessions and projects. It ensures AI assistants never forget past interactions, offering cross-project recall and persistent knowledge without sending data to the cloud.

01

TL;DR

letta logo
lettaMemory & Context · ★ 25.2k
When to choose:
  • You want a long-lived agent that remembers past work and rewrites its own memory and context over time.
  • You want one agent reachable from CLI, desktop, browser, mobile and messaging apps, with subagents, schedules and hooks.
  • You want memory you can inspect: the README says context is tracked in git and can sync to your own repository.
When to skip:
  • You only need to add memory to an agent you already use through MCP; a small MCP memory server is a lighter fit.
  • You rely on older Letta tutorials or the V1 API server: the project restructured, and the V1 server is retired.
  • You want everything to work without signing in: Letta Cloud is the default backend and some features need it.
Read letta full review →
Yggdrasil logo
YggdrasilMemory & Context · ★ 22

Prevent AI agents from forgetting project context in new sessions.

Read Yggdrasil full review →
02

Side-by-Side Comparison

Field
letta logoletta
Yggdrasil logoYggdrasil
Category
Memory & Context
Memory & Context
Stars
★ 25.2k
★ 22
License
Apache-2.0
AGPL-3.0
Install Command
npm install -g @letta-ai/letta-code
uvx --from yggdrasil-memory ygg install
Updated
5d ago
1d ago
Open Source
Yes
Yes
Website
↗ Visit
↗ Visit
GitHub
↗ GitHub
↗ GitHub
Tags
Stateful AI, Agent Platform, Advanced Memory
Local Memory, AI Agent, Persistent Context
03

Features

letta logoletta
01Build stateful AI agents with advanced memory
02Agents capable of learning and self-improvement over time
03CLI tool for running agents locally in your terminal
04Comprehensive API for integrating agents into applications
05Support for skills and subagents; fully model-agnostic
Yggdrasil logoYggdrasil
01Persistent memory across sessions, tools, and projects.
02Shared memory for Claude Code, Codex, and other MCP agents.
03Cross-project recall to reuse past solutions and decisions.
04100% local operation with no cloud dependency or telemetry.
05Zero-dependency default mode using SQLite + FTS5 for keyword search.
04

Use Cases

letta logoletta
↳Running AI agents locally in your terminal for coding and general tasks.
↳Integrating stateful AI agents into custom applications using the API and SDKs.
↳Developing self-improving AI systems that adapt and learn continually.
Yggdrasil logoYggdrasil
↳Prevent AI agents from forgetting project context in new sessions.
↳Allow AI agents to leverage decisions and lessons learned from other projects.
↳Consolidate existing knowledge sources (e.g., transcripts, Obsidian vaults) into a unified memory.
↳Provide a consistent identity and persona for AI assistants across tools.
05

Best For

letta logoletta
Most PopularEssentialTrending
Yggdrasil logoYggdrasil
—
FAQ

FAQ

What is the difference between letta and Yggdrasil?
Both letta and Yggdrasil are in the Memory & Context category. letta has 25.2k stars, while Yggdrasil has 22 stars.
Which is better, letta or Yggdrasil?
The best choice depends on your use case. Choose letta if Running AI agents locally in your terminal for coding and general tasks., and Yggdrasil if Prevent AI agents from forgetting project context in new sessions..
Is letta free or open source?
Yes, letta is open source on GitHub (Apache-2.0).
Is Yggdrasil free or open source?
Yes, Yggdrasil is open source on GitHub (AGPL-3.0).
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