kitio.aiHermes Agent vs Letta
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Hermes Agent starts at See pricing page and Letta starts at $20/mo. Check both pricing pages for current plans.
At a glance
Best for
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Editable Markdown memory
- Scheduled jobs
- Local, Docker or cloud runtime
- Approval modes
- Command allowlists
- Persistent agent memory
- Agent SDK and API
- Agent Development Environment
- Cloud or self-hosted
- Agent export and import
| Feature | Hermes Agent | Letta |
|---|---|---|
| Best for | Open-source personal agent with editable Markdown memory | Platform for stateful AI agents with long-term memory |
| Category | Agents & automation | Agents & automation |
| Pricing model | Freemium | Freemium |
| Starting price | See pricing page | $20/mo |
| Free plan | Yes | Yes |
| Made by | Nous Research | Letta |
| Based in | United States | United States |
| Rating | No ratings yet | No ratings yet |
| Key features |
|
|
Pricing compared
Hermes Agent starts at See pricing page and Letta starts at $20/mo. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
5 plans
Free
Free
- Limited stateful agents
- 5 MiB storage per memory repo
- Bring your own API keys
Pro
$20/mo
- Up to 20 stateful agents
- Letta Auto weekly + monthly quota
- 50 MiB storage per memory repo
Teams Pro
$20/mo
- Per seat
- Share agents with access control
- All Pro features
API Plan
$0.10 / active agent / mo
- Unlimited agents
- $0.00015 per sec tool execution
- Pay-as-you-go LLM usage
Enterprise
Contact sales
- Role-based access control
- SAML/OIDC SSO
- Dedicated support
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Hermes Agent
- Transparent, editable memory
- Flexible places to run it
- Good safety controls
- Requires setup and maintenance
- Model costs are separate
Letta
- Strong long-term memory design
- Open-source core
- Clear view of agent state
- Developer-focused
- Free plan limited to a few agents
Which one should you choose?
Choose Hermes Agent if you want:
- Transparent, editable memory
- Flexible places to run it
- Good safety controls
Watch out: requires setup and maintenance.
Choose Letta if you want:
- Strong long-term memory design
- Open-source core
- Clear view of agent state
Watch out: developer-focused.
Hermes Agent vs Letta FAQ
What is the difference between Hermes Agent and Letta?
Hermes Agent: Open-source personal agent with editable Markdown memory. Letta: Platform for stateful AI agents with long-term memory. Both are agents & automation tools.
Is Hermes Agent or Letta cheaper?
Hermes Agent starts at See pricing page and Letta starts at $20/mo. Check both pricing pages for current plans.
Do Hermes Agent and Letta have free plans?
Hermes Agent: Yes. Letta: Yes.
Who makes Hermes Agent?
Hermes Agent is made by Nous Research, based in United States.
Who makes Letta?
Letta is made by Letta, based in United States.
Which should I choose, Hermes Agent or Letta?
Choose Hermes Agent if you value transparent, editable memory and flexible places to run it. Choose Letta if you value strong long-term memory design and open-source core.