LangChain vs Letta

Choose LangChain if…

Best for developers building custom applications on top of large language models, and its edge is composable chains, agents, and memory abstractions that cut LLM app code from hundreds of lines to dozens. The standard starting framework for LLM app development, expect the API to keep shifting under you. Lean toward Letta instead if manages its own memory tiers and decides what to retain or summarize, more reliable than an ad-hoc RAG memory hack matters more for your use case.

Choose Letta if…

Best for developers building agents that need to remember and update facts across arbitrarily long interaction histories, and its edge is manages its own memory tiers and decides what to retain or summarize, more reliable than an ad-hoc RAG memory hack. A genuinely more solid approach to agent memory than manual context management, per-step cloud pricing adds up for memory-heavy agents. Lean toward LangChain instead if composable chains, agents, and memory abstractions that cut LLM app code from hundreds of lines to dozens matters more for your use case.