Hermes Agent
Hermes Agent is Nous Research's MIT-licensed self-hosted agent that keeps persistent memory across sessions, writes and refines its own skills from experience, and reaches you through Telegram, Discord, Slack, WhatsApp, Signal or the terminal.
Pros
- Fully open source under the MIT licence and among the most heavily adopted agent projects on GitHub, with roughly 239,000 stars and 48,800 forks on github.com/NousResearch/hermes-agent, which means no vendor lock-in and a large body of community deployments to learn from. The learning loop is the real differentiator: it creates skills from experience and improves them in use, nudges itself to persist what it learns, searches its own past sessions in full text, and builds a model of how you work across sessions rather than starting cold each time. It is deliberately model-agnostic, running against Nous Portal, OpenRouter, OpenAI, Anthropic or any custom endpoint with a switch rather than a rewrite, and it ships more than 40 built-in tools plus MCP support, a cron scheduler for natural-language automations, and parallel subagents with isolated conversations. Deployment is genuinely flexible, covering Linux, macOS, WSL2, Termux, native Windows and Docker, along with Modal, Daytona, Vercel Sandbox, SSH and Singularity backends and desktop apps for macOS 12+, Windows 10/11 and Linux, so it will sit equally happily on a $5 VPS or a GPU box.
Cons
- Self-hosting is the deal, not a footnote: you own the server, the upgrades, the API keys and the blast radius, and this is an agent with real tool access, messaging gateways and a browser, so a careless instruction or a poisoned input has consequences beyond a bad reply. Release cadence is very fast and calendar-versioned, with v2026.8.31 published on 31 August 2026 and pushes landing daily, which is great for features and poor for stability unless you pin a tag and read the changelog before every upgrade. The paid layer is Nous Portal and its public overview page advertises the included credit allowances but not the headline monthly subscription price for each tier, so you cannot see what a plan actually costs before creating an account. Hosted tools and cloud agent hosting bill against the same credit balance as model calls, which makes a runaway agent an expense as well as a risk, and there is no managed, supported, someone-else-runs-it edition at all.
Cost
The agent itself is free and open source under the MIT licence, self-hosted, with your only unavoidable costs being the server it runs on and whatever model provider you point it at. Nous Portal is the optional first-party layer: a Free tier gives free models only at standard rate limits with $0 in monthly credits, while Plus includes $22 in monthly credits with a $10 rollover cap, Super includes $110 with a $50 rollover cap, and Ultra includes $220 with a $100 rollover cap, each advertising a 10% bonus, 200+ models, hosted tool usage and high rate limits. The public overview page shows those credit allowances but does not render the headline monthly price for each tier. Top-ups of $10, $20, $50, $100 and $200 are available through Stripe, and hosted tools such as web search, scraping, image generation, browser use and speech are priced per use against the same credit balance, as is cloud hosting of the agent.
Verdict
Best for developers and technical operators who want a persistent, memory-keeping assistant they fully control and can point at any model, and who are comfortable running and securing their own server; anyone wanting a supported, hands-off product with a price on the tin should look elsewhere.
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