Google ADK vs Letta
Side-by-side comparison of two agent options that often come up together when people are choosing between self-hosted frameworks, managed assistants, and extensible AI tooling.
Open source19k stars
Google ADK
Google's open-source code-first Python toolkit for building and evaluating AI agents
Open source22k stars
Letta
Platform for building stateful agents with advanced memory persistence
Category
Google ADK
Letta
Tagline
Google's open-source code-first Python toolkit for building and evaluating AI agents
Platform for building stateful agents with advanced memory persistence
Deployment
Self-Hosted
Self-Hosted
Pricing
Free to use, with optional model or infrastructure costs if you self-host.
Usually affordable for individuals or small teams, with some recurring model or hosting costs.
Channels
Web, CLI
Telegram, Slack, Discord, WhatsApp, Signal
Open source
Yes
Yes
Privacy
Some privacy controls exist, but vendor-hosted infrastructure still handles a meaningful share of the data flow.
Good privacy posture for most teams, especially when self-hosted or carefully configured.
Google ADK pros
- Official Google backing
- Built-in evaluation framework
- Multi-agent orchestration
Letta pros
- Open source with transparent code and flexible deployment options.
- Strong privacy story for users who care where data runs.
- Good memory and persistence support for ongoing conversations or tasks.
Google ADK cons
- Python-only
- Development framework, not ready-to-use assistant
- Google Gemini API dependency
Letta cons
- Lower autonomy — designed more as a platform than an out-of-box assistant
- Setup requires understanding memory architecture concepts
- Python-only — no native TypeScript/JavaScript implementation
Google ADK gotchas
- You should expect ongoing hosting, uptime, and secret-management work if you deploy it for real users.
Letta gotchas
- You should expect ongoing hosting, uptime, and secret-management work if you deploy it for real users.
- Recurring subscription or model spend can matter more than the headline feature list.
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