Letta: review, pricing, security and alternatives

What Letta does

Letta belongs to the frameworks family: libraries for building your own agents in code: loop, tools, memory, orchestration. On our grid it ranks #11 of the 28 projects of this family listed in the directory.

You use it from: API, developer SDK, and web app. Usable models: Claude (Anthropic), GPT (OpenAI), local models (Ollama, llama.cpp, vLLM…), and any OpenAI-compatible model. It can run on your own machine or server.

Who is Letta for?

It is for developers building their own agent or adding agentic AI to a product. Typical tasks people give it:

• build a business agent wired to your APIs
• orchestrate tool and model calls
• add memory and error recovery to an agent

It is a good candidate if you prefer doing everything in a browser, with no install, your data must stay on your machines, and you want the option of a local model, with no API fees.

Access and human control

Its documentation does not detail the access granted to the agent: check the settings before connecting it to your accounts.

We could not establish whether it asks for human approval before sensitive actions: test it first on an unimportant account or folder.

Letta pricing

The code is free, under the Apache-2.0 licence.

Getting started with Letta

1. Install it by following the repository README.
2. Pick the model: an API key from a provider, or a local model if your machine has enough graphics memory (the VRAM calculator tells you).
3. Give it a first playground with nothing at stake: a test folder, a secondary account or a throwaway project. Only open your real accounts once you have seen how it behaves.
4. Give it a short, checkable task, review the result and its action log, then raise the difficulty step by step.

Security: risk level

A framework does not protect you by default: approval, minimal rights and sandboxing are up to you.

Three habits: least privilege (minimal rights, dedicated keys), human approval for irreversible actions, a sandbox for code execution. The AI agent security check reviews your setup in a few minutes.

Project activity and releases

Created on October 11, 2023, the letta-ai/letta repository has 25,241 stars, 2,656 forks and 0 open issues, with 7,476 commits in total. It received changes this month.

Over the last 52 weeks: 1,203 commits, an average of 23.1 per week.

177 releases in total; 11 in the last twelve months. Latest release: 0.16.8, on May 14, 2026.

Letta vs other frameworks

GitHub stars of the best-rated open-source projects in the frameworks family. Stars measure attention, not quality: a heavily promoted project collects them fast, a specialised tool will have few.

Letta and other frameworks at a glance

The 7 best-ranked agents in the same family, 7 of them open source. The score out of 100 only applies to open-source projects; for proprietary services we show the published entry price. A dash marks information the documentation does not state.

How we rated it

Score: 78/100, computed only from public, verifiable data, with no subjective testing or partnership:

• Adoption 29/40: 25,241 stars on a log scale (40 points from about 200,000).
• Activity 24/30: last commit less than a month ago, 1 release in six months, 1,203 commits in a year.
• Framework 25/30: licence, default human approval, self-hosting, model choice and documentation site.

The score does not say whether the agent will succeed at your tasks: it measures how solid the project is. The full grid is on the method page.