Review · Software & AI
Letta review
An open source platform for stateful agents with long-term memory, offered as an agent SDK, a CLI, a self-hosted server and Letta Cloud.
By the DBotMaker research desk · Updated November 6, 2026
- Capabilities (40%)
- 8.0
- Ease of setup (30%)
- 7.8
- Value (30%)
- 7.8
Letta is built around one idea: agents should keep long-term memory and get better with use. Its open source agent harness, licensed under Apache 2.0, stores memory in repositories the agent reads and edits, supports shared memory between agents, and adds skills, schedules and subagents for recurring work. Developers embed agents through the Letta Agent SDK for TypeScript applications, then choose managed Letta Cloud or run the full runtime themselves with the Letta App Server. Agents can also live in Slack, Telegram, Discord, WhatsApp and Signal through channels. Pricing is the cheapest verified paid entry here: Pro is $20 a month with up to 20 stateful agents and a Letta Auto quota, and the API plan for developers is $20 a month with unlimited agents, $0.10 per active agent and per-second tool execution fees. The free plan caps you at 3 stateful agents. Recent releases lean toward coding and personal assistants, so general app builders should check the SDK docs closely.
Who it is for
Developers building agents that must remember users and improve with use over weeks or months.
Price
Free plan with your own API keys; Pro $20 per month; API plan $20 per month plus usage.
Pro For personal use. $20 /month
Quoted from the vendor pricing page on November 6, 2026.
Key features
- Stateful agents with a memory system and shared memory
- Skills, schedules and subagents for recurring work
- Agent SDK for building agents into TypeScript applications
- Channels for Slack, Telegram, Discord, WhatsApp and Signal
- Managed Letta Cloud or self-hosted App Server
Strengths and weaknesses
- Strength: Memory is the core design rather than an add-on
- Strength: Free plan works with your own keys and existing coding plans
- Strength: Lowest verified paid entry price on this list
- Weakness: Free plan is limited to 3 stateful agents
- Weakness: API plan adds $0.10 per active agent a month plus tool execution fees
- Weakness: Product focus has shifted toward coding and personal agents
Key facts
- License: Apache 2.0
- Free: $0, limited agents, bring your own keys
- Pro: $20 a month, up to 20 stateful agents
- API plan: $20 a month, unlimited agents, $0.10 per active agent
Where it ranks
Letta is No. 9 in our Best AI Agent Frameworks verdict.
Alternatives we scored
Visit letta.com · Questions or corrections: editorial@dbotmaker.io