What is Hermes good for?

Hermes suits model research and reasoning tasks (math, code, logic), while Hermes Agent is for building autonomous workflows with learning and memory.

What's the difference between Hermes and ChatGPT?

Hermes is open source, locally deployable, and fine-tunable; ChatGPT is a closed commercial service that's more turnkey.

Which Hermes model sizes are available?

The Hermes-4 series spans 14B (lightweight local), 70B (balanced), and 405B (flagship), all deployable and fine-tunable locally.

How to Use Hermes: Tutorial (Nous Research Open Source AI)

Author: UPGPTs TeamFirst published: 2026-08-09Last updated: 2026-08-09

TL;DR: Hermes is Nous Research's open-source AI project — the Hermes 4 model series (hybrid reasoning LLMs) plus Hermes Agent, a self-evolving AI agent. Want a quick try? Chat online at chat.nousresearch.com. Want it local? Clone the repo with Git and run ./start.sh.

Hermes is Nous Research's open-source AI project. It includes the Hermes 4 model series (hybrid reasoning LLMs) and Hermes Agent, a self-evolving AI agent.

Full translation in progress. The Chinese source file for this article is the authoritative version.

Quick Steps

Try it online for free — visit chat.nousresearch.com and start chatting, no install required

Install Hermes Agent — clone and run with Git only:

bash

git clone https://github.com/NousResearch/hermes-agent && cd hermes-agent && ./start.sh

Pick a model size that fits your needs (Hermes-4-14B is lightweight, 405B is the flagship)
Use hybrid reasoning (thinking tag) for math, coding, and logic tasks

Key Features

Hybrid reasoning mode: shows its thinking process via thinking tags
Strong reasoning: big improvements in math, code, STEM, and logic
Structured output: generates valid JSON per a given schema
Tool calling: native ChatML format, works with vLLM / SGLang

Pros and Cons

Hermes advantages

Open source and deployable: models and the agent run locally and are fine-tunable — data stays under your control
Cost-controllable: compared with closed commercial subscriptions, local deployment avoids per-use fees
Clear positioning: reasoning tasks (math, code, logic) and autonomous workflows are its strengths

Limitations / things to note

Deployment has a learning curve: local install needs Git and environment setup — not turnkey
Capability depends on the chosen size: the 14B lightweight version is a long way from the 405B flagship
Smaller ecosystem: fewer plugins and less Chinese material than ChatGPT or Claude

Who It's For

Developers and AI enthusiasts researching models and reasoning
Teams that need a local, controllable, fine-tunable AI solution
Advanced users building learning-and-memory workflows with an agent

About the Author

UPGPTs Team creates step-by-step, screenshot-heavy tutorials for AI tools like ChatGPT, Claude, Grok and Codex. Find more in the UPGPTs Tutorial Hub, check the FAQ, or reach us via the Contact page.