Hermes Agent vs Letta (2026): which should you pick?
As of Nov 12, 2026, Hermes Agent grades higher than Letta: 2.8 against 2.0 out of 4.0.
Checked Nov 9, 2026 and Nov 12, 2026 · graded Nov 9, 2026 and Nov 12, 2026 by ToolGPA
Hermes Agent grades higher on value for money, the free plan and ease of use. They get the same grade on features and platforms.
Price, platforms and features side by side. The table says where each price was read and when.
Hermes Agent
Open-source AI agent with persistent memory and a messaging gateway
Letta
Stateful agents with long-term memory, from the MemGPT team
Which one is for you
Pick Hermes Agent if
- Fits if you're a developer who wants an agent on your own machine, server or VPS
- Works for jobs that run unattended, like a scheduled report or a morning briefing sent to your chat app
Look elsewhere if
- Skip it if you want an app on your phone: no iOS version is listed, and Android is a prerelease Termux package
- Not for you if setting up providers and chat platforms sounds like work, because it is
- Pricey if you want paid models all day, as they're billed on top, from $20 a month on Nous Portal
- Watch out: Portal tiers are described as multiples of Plus usage with no dollar allowance, and extra Cloud agents are billed daily at prices shown only inside Nous Portal
- Watch out: on Linux there's no desktop app, so the install is through the terminal
Pick Letta if
- Fits if you are a developer who wants agents that keep their memory between runs
- Works for people who already pay for a coding plan and can bring that key
Look elsewhere if
- Tight if you stay free, because there is no included model usage and 3 agents is the cap
- Pricey if you code heavily, as the pricing page says $100 to $200 a month or more of usage
- Watch out: server tool time is billed at $0.00015 a second against your credits
- Watch out: more than one person needs Teams Pro, since Pro covers a single user
How we grade them
| 2.8GPAHermes AgentGood | 2.0GPALettaFair | |
|---|---|---|
| Value for money | BThe agent itself is MIT licensed and costs nothing, with no paid edition. The models are the bill: your own provider's rates, or Nous Portal from $20 a month, which covers paid models, hosted tools and one Cloud agent. The listing gives Super and Ultra only as 5 and 10 times Plus usage, not in dollars. | CPro is $20 a month with $20 of credits, around the category's $21 middle. Teams Pro is $20 a seat. |
| Free plan and trial | AThe whole agent is free and open source with nothing held back, and a free Nous Portal account runs it on free models with no monthly credits needed. Bring your own key and there's no cap from Nous at all. | CFree covers 3 stateful agents but no model usage, so you bring your own keys or buy credits. |
| Features | CThe parts: memory that survives sessions, skills it writes from work it has done, cron described in plain words, subagents, commands sandboxed in Docker or Modal, and 20-plus chat platforms sharing one memory. It's a developer's framework, with model access sold separately and no hosted product. | CPersistent memory, a coding CLI, an SDK, and Slack and GitHub channels. Memory repositories are capped at 5 MiB on Free, and web search and tools spend credits. |
| Ease of use | CDesktop apps for Mac and Windows, a terminal install on Linux, and either way you connect a model provider first and set up each messaging platform yourself before you can chat there. No rating on record. | DNo store rating, and the main route is an npm-installed CLI and SDK, so you work from a command line. |
| Platforms and integrations | BMac, Windows and Linux, with optional always-on hosting, and it answers on more than 20 platforms including Telegram, Discord, Slack, WhatsApp and Teams. No iOS version, and Android only through a prerelease Termux package. | BWeb plus a CLI and SDK, with Slack, GitHub, Telegram, Discord, WhatsApp and Signal channels. |
| Best for | a free agent you message from your chat apps | developers building agents that remember across sessions |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: Hermes Agent and Letta. How we grade
Price against what you get
Hermes Agent starts at $20 a month and scores 2.3 out of 4 on features, ease of use and platforms. Letta starts at $20 a month and scores 2.0.
Hermes Agent scores higher for the same starting price. Of the other AI agents on the chart, 13 score higher than Hermes Agent for less, and 17 score higher than Letta for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- Hermes Agent is self-hostable, according to its own site.
- Hermes Agent also covers chat assistant.
At a glance
| Hermes Agent | Letta | |
|---|---|---|
| Pricing | Free plan | Free plan |
| Starts at | $20 per month for the optional Nous Portal Plus tier; the agent is free | $20 per month |
| Free plan | Hermes Agent is free and open source under the MIT license. You connect your own model provider, or a free Nous Portal account that is limited to free models. | Up to 3 stateful agents and 5 MiB per memory repository; bring your own API keys or an external coding plan. |
| Free trial | None listed | None listed |
| Web | ||
| macOS | ||
| Windows | ||
| Linux | ||
| Made by | Nous Research, Inc. | Letta, Inc. |
| Price read from | hermes-agent.nousresearch.com | docs.letta.com |
| Checked | Nov 9, 2026 | Nov 12, 2026 |
Worth knowing
Hermes Agent
- The agent is free, but paid models cost extra: your own provider's rates, or Nous Portal tiers from $20 a month.
- Desktop apps are offered for macOS and Windows; on Linux the install is through the terminal.
- The platform support page lists no iOS version, and Android runs only through a prerelease Termux package.
- Hermes Cloud needs $2 of Nous credit or a subscription to deploy; extra instances are billed daily from credit at sizes and prices shown only inside Nous Portal.
Letta
- The free plan has no included model usage; you bring your own keys or buy credits.
- Credits are spent by model usage at provider-based rates, and the pricing page says heavy coding use can run $100 to $200 a month or more.
- Server-side tool time is billed at $0.00015 per second against credits, and web search and fetch tools also cost credits.
- Adding members to an organization needs Teams Pro; Pro covers a single user.
Key features
Hermes Agent
- Messaging gateway
- One gateway connects the agent to Telegram, Discord, Slack, WhatsApp, Signal, Matrix, email, Microsoft Teams and other platforms, more than 20 in all, sharing a single memory.
- Memory and self-written skills
- The agent keeps memory across sessions, creates reusable skills from work it has done and revises them in use. Skills follow the open agentskills.io format.
- Scheduled automations
- Built-in cron accepts natural-language schedules for reports, backups and briefings and delivers the results to any connected platform.
- Subagents
- Isolated subagents with their own conversations and terminals handle parallel workstreams without filling the main agent's context.
- Terminal backends and sandboxing
- Commands run locally or in Docker, over SSH, or on Daytona, Singularity, Modal or Vercel Sandbox, with command approval and container isolation.
- Nous Portal and Hermes Cloud
- A Portal subscription covers 200+ models and hosted web search, image generation, text-to-speech and browser tools, plus one always-on Cloud agent; extra hosting is billed daily.
Letta
- Persistent agent memory
- Agents are stateful: they carry memory across sessions, and memory repositories are versioned in git so changes can be tracked.
- Letta Code CLI
- An open-source harness installed with npm for coding agents, personal assistants and agents that work on local files, with skills and schedules.
- Agent SDK and app server
- Developers can embed stateful agents in their own applications, with a self-hosting option and a protocol for external tools.
- Channels and cloud agents
- Cloud-hosted agents connect to Slack and a GitHub integration; the channels guide also lists Telegram, Discord, WhatsApp and Signal.
- Bring your own keys
- All plans accept your own model API keys, and usage then goes through your provider account instead of using Letta credits.
Plans
Hermes Agent
Hermes Agent$0
The complete MIT-licensed agent, run on your own machine or server with a model provider of your choice.
Nous Portal Free$0
Free models only, standard rate limits and pay-as-you-go top-ups; no hosted tools or Cloud agent.
Nous Portal Plus$20
per month
Paid and free models from 200+, hosted web search, image, speech and browser tools, high rate limits and one Cloud agent of 4 GB RAM and 25 GB disk.
Nous Portal Super$100
per month
Five times the usage of Plus, with the same models and hosted tools and one Cloud agent of 4 GB RAM and 100 GB disk.
Nous Portal Ultra$200
per month
Ten times the usage of Plus, with the same models and hosted tools and one Cloud agent of 8 GB RAM and 100 GB disk.
Letta
Free$0
per month
Up to 3 stateful agents; no included model usage, so bring your own keys or buy credits.
Pro$20
per month
Includes $20 of credits a month for any model and remote sandboxes, up to 20 stateful agents.
Teams Pro$20
per seat / month
Everything in Pro, plus teammates in an organization, shared agents and access control.
EnterpriseCustom
Volume-based pricing with role-based access control, SAML/OIDC SSO and dedicated support.
Common questions
Which is cheaper, Hermes Agent or Letta?
As of Nov 12, 2026, they start at the same price. Hermes Agent starts at $20 per month for the optional Nous Portal Plus tier; the agent is free, and Letta starts at $20 per month.
Which has a free plan, Hermes Agent or Letta?
As of Nov 12, 2026, both Hermes Agent and Letta have a free plan.
Which platforms do Hermes Agent and Letta run on?
As of Nov 12, 2026, only Hermes Agent lists macOS, Windows and Linux apps. Both list a web app. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.