Letta by Letta
Stateful agent platform (formerly MemGPT) with persistent, self-editing memory.
Memory for agents Official MCP server Open source
Price
Free plan
paid plans from $20/mo
Free tier
Yes
Free plan $0/month, limited agents (3 stateful agents),...
SDK downloads
161K
npm @letta-ai/letta-client · PyPI letta-client
Pricing
| Free tier | Free plan $0/month, limited agents (3 stateful agents), bring your own API keys |
|---|---|
| Cheapest paid plan | $20 a month |
| Usage price | API plan $20/month + $0.10 per active agent per month + $0.00015/sec tool execution + LLM tokens at cost |
| Good to know | Personal Pro is also $20/month (up to 20 agents, Letta Auto quota). Teams Pro $20/seat/month. Open-source server can be self-hosted. Note the PyPI package 'letta' now points to Letta Code; use letta-client for the API. |
From the official pricing page, checked Oct 9, 2026. Prices change: confirm before you buy.
Use it from an agent
| MCP server | Official: https://api.letta.com/mcp |
|---|---|
| npm | npm install @letta-ai/letta-client |
| PyPI | pip install letta-client |
| GitHub | letta-ai/letta · 25.1K stars · last push Sep 10, 2026 |
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| API | Free | Price | SDK downloads / wk | GitHub stars | MCP |
|---|---|---|---|---|---|
| Supermemory Memory and retrieval API that builds per-user memory graphs from text, files and connectors. |
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