Letta (MemGPT)
RAG & Memory · Free + paid
OS-inspired memory management for LLMs enabling unbounded virtual context
At a glance
- Made by
- Letta
- Korean
- None (English and a few others only)
- API
- Yes
- Available on
- Web, Windows, Mac, CLI, API
- Open source
- Open source (the license name is not listed on the page)
- GitHub
- 25,125 stars · Apache-2.0
What is Letta (MemGPT)?
Letta (formerly MemGPT) is a platform for building stateful agents that have memory. The agent harness is fully open source, and you can build coding agents, personal assistants, AI coworkers, and agents embedded in apps. You can use it through a CLI, a web app, a desktop app, channels such as Slack, Telegram, and Discord, and an Agent SDK for TypeScript. You can use the managed Letta Cloud or run it yourself with the Letta App Server.
- Stateful agents with memory
- Extend capabilities with Skills
- Automate recurring tasks with Schedules
- Slack, Telegram, Discord, WhatsApp, and Signal channel integrations
- Run agents in a cloud sandbox
- Self-hosting with the Letta App Server
- Letta Agent SDK for TypeScript
- Desktop apps for macOS, Windows, and Linux
Who uses Letta (MemGPT) and for what
- AI coding assistant
- Personal assistant for work
- AI coworker in Slack, Telegram, and Discord
Pricing
What you get for free — Yes (up to 3 stateful agents, BYOK)
| Plan | Price | Main limits |
|---|---|---|
| Free | $0/mo | Agent limits, limited use of Letta Auto, your own API keys |
| Pro | $20/mo | Weekly and monthly Letta Auto quotas, pay-as-you-go for overage, up to 20 stateful agents |
| API Plan | $20/mo | Unlimited agents, $0.10 per month per active agent, $0.00015 per second of tool execution, pay-as-you-go LLM usage |
| Teams Pro | $20 | Add team members, share agents, and set permissions |
| Enterprise | Contact sales | Custom volume-based pricing, SAML/OIDC SSO |
Checked on the official pages on 2026-10-14. Prices and features can change, so check the official site again before paying. · Official pricing page
AI tools similar to Letta (MemGPT) (alternatives)
Letta (MemGPT) vs. alternatives at a glance
| AI | Pricing | Combos on the map | Connected tools | Free | Cheapest monthly | Korean |
|---|---|---|---|---|---|---|
| Letta (MemGPT) | Free + paid | 0 | 4 | Yes | $20/mo | No |
| Cognee | Free | 0 | 4 | Yes | — | No |
| Mem0 | Free | 0 | 4 | Yes | $19/mo | No |
| supermemory | Free + paid | 0 | 4 | Yes | $19/mo | No |
| Zep | Free | 0 | 4 | Yes | $125/mo | No |
5 of these 5 tools have a free plan. Cheapest paid plan: Mem0 ($19/mo).
Combo and connection counts are based on the relationships recorded on AI Galaxy Map (2026-10-26); they are not a quality ranking.
Letta (MemGPT) on AI Galaxy Map
- One of 21 AI tools in the RAG & Memory field.
- Connected to 4 other tools — #7 in its field.
Frequently asked questions
Can I use Letta (MemGPT) for free?
Yes (up to 3 stateful agents, BYOK). Prices can change, so check the official site before paying.
What AI can I use instead of Letta (MemGPT)?
Tools that do the same job, such as Cognee, Mem0, supermemory, Zep, are connected to it on the map.
Can I use Letta (MemGPT) in Korean?
None (English and a few others only)
Sources (official pages)
Checked on the official pages on 2026-10-14. Prices and features can change, so check the official site again before paying.