Nous Research: Hermes 4 405B
nousresearch/hermes-4-405b
Access Hermes 4 405B from Nous Research using Puter.js AI API.
Get Started// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';
puter.ai.chat("Explain quantum computing in simple terms", {
model: "nousresearch/hermes-4-405b"
}).then(response => {
document.body.innerHTML = response.message.content;
});
<html>
<body>
<script src="https://js.puter.com/v2/"></script>
<script>
puter.ai.chat("Explain quantum computing in simple terms", {
model: "nousresearch/hermes-4-405b"
}).then(response => {
document.body.innerHTML = response.message.content;
});
</script>
</body>
</html>
# pip install openai
from openai import OpenAI
client = OpenAI(
base_url="https://api.puter.com/puterai/openai/v1/",
api_key="YOUR_PUTER_AUTH_TOKEN",
)
response = client.chat.completions.create(
model="nousresearch/hermes-4-405b",
messages=[
{"role": "user", "content": "Explain quantum computing in simple terms"}
],
)
print(response.choices[0].message.content)
curl https://api.puter.com/puterai/openai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_PUTER_AUTH_TOKEN" \
-d '{
"model": "nousresearch/hermes-4-405b",
"messages": [
{"role": "user", "content": "Explain quantum computing in simple terms"}
]
}'
Model Card
Hermes 4 405B is a frontier hybrid-mode reasoning model based on Llama-3.1-405B, trained on a 60B token dataset with verified reasoning traces. It features toggleable deep reasoning via think tags, massive improvements in math, code, STEM, and logic, and achieves state-of-the-art on RefusalBench for reduced censorship.
Context Window 131K
tokens
Max Output N/A
tokens
Input Cost $1
per million tokens
Output Cost $3
per million tokens
Release Date Aug 6, 2025
Output Speed 32
tokens / sec
Latency 0.91s
time to first token
Model Playground
Try Hermes 4 405B instantly in your browser.
This playground uses the Puter.js AI API — no API keys or setup required.
Benchmarks
How Hermes 4 405B performs on standard evaluations.
| Benchmark | Score |
|---|---|
| GPQA Diamond Graduate-level science Q&A | 53.6% |
| Humanity's Last Exam Cross-domain reasoning | 4.2% |
| LiveCodeBench Recent coding problems | 54.6% |
| SciCode Scientific programming | 34.6% |
| AIME 2025 Advanced math exam | 15.3% |
| IFBench Instruction following | 34.8% |
| LCR Long-context reasoning | 20.0% |
| Terminal-Bench Hard Agentic terminal tasks | 9.8% |
| τ²-Bench Tool use / agents | 26.6% |
Scores sourced from Artificial Analysis.
Find other Nous Research models →
Hermes 4 70B
Hermes 4 70B is a hybrid reasoning model based on Llama-3.1-70B with toggleable deep thinking mode using think tags. It offers major improvements in math, code, STEM, logic, and creative writing while supporting JSON schema adherence, function calling, and reduced refusal rates compared to other models.
ChatHermes 3 405B Instruct
Hermes 3 Llama 3.1 405B is a frontier-level 405B parameter full fine-tune of Llama-3.1-405B, focused on user alignment with powerful steering capabilities. It features advanced agentic capabilities, roleplaying, reasoning, multi-turn conversation, and improved code generation, competitive with or superior to Llama-3.1 Instruct models.
ChatHermes 3 70B Instruct
Hermes 3 Llama 3.1 70B is a 70B parameter fine-tune of Llama-3.1-70B offering advanced agentic capabilities, improved roleplaying, reasoning, and multi-turn conversation. It provides reliable function calling and structured outputs while being competitive with Llama-3.1 Instruct models at a more accessible size.
Frequently Asked Questions
You can access Hermes 4 405B by Nous Research through Puter.js AI API. Include the library in your web app or Node.js project and start making calls with just a few lines of JavaScript — no backend and no configuration required. You can also use it with Python or cURL via Puter's OpenAI-compatible API.
Yes, it is free if you're using it through Puter.js. With the User-Pays Model, you can add Hermes 4 405B to your app at no cost — your users pay for their own AI usage directly, making it completely free for you as a developer.
| Price per 1M tokens | |
|---|---|
| Input | $1 |
| Output | $3 |
Hermes 4 405B was created by Nous Research and released on Aug 6, 2025.
Hermes 4 405B supports a context window of 131K tokens. For reference, that is roughly equivalent to 262 pages of text.
Yes — the Hermes 4 405B API works with any JavaScript framework, Node.js, or plain HTML through Puter.js. Just include the library and start building. See the documentation for more details.
Get started with Puter.js
Add Hermes 4 405B to your app without worrying about API keys or setup.
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