--- title: Hermes 3 405B Instruct — Frontier LLM | ModelsLab description: Access Nous: Hermes 3 405B Instruct via API for agentic reasoning, code generation, and structured outputs. Generate complex responses now. url: https://modelslab.com/nous-hermes-3-405b-instruct canonical: https://modelslab.com/nous-hermes-3-405b-instruct type: website component: Seo/ModelPage generated_at: 2026-07-01T04:03:05.804849Z --- Available now on ModelsLab · Language Model Nous: Hermes 3 405B Instruct Steer Frontier Reasoning --- [Try Nous: Hermes 3 405B Instruct](/models/open_router/nousresearch-hermes-3-llama-3.1-405b) [API Documentation](https://docs.modelslab.com) Unlock Hermes Capabilities --- 131K Context ### Process Long Inputs Handle 131K token context for multi-turn conversations and long documents. Agentic Power ### Enable Advanced Agents Supports function calling, roleplaying, and structured outputs in Nous: Hermes 3 405B Instruct. 16K Output ### Generate Detailed Responses Produce up to 16K tokens per response for complex reasoning and code tasks. Examples See what Nous: Hermes 3 405B Instruct can create --- Copy any prompt below and try it yourself in the [playground](/models/open_router/nousresearch-hermes-3-llama-3.1-405b). Code Refactor “Refactor this Python function for efficiency and add type hints: def calculate\_fib(n): if n <= 1: return n; return calculate\_fib(n-1) + calculate\_fib(n-2)” JSON Schema “Generate a JSON schema for a user profile with fields: name, email, age, preferences as array of strings. Include validation rules.” Logic Puzzle “Solve this riddle step-by-step: Three houses in a row, owned by Brit, Swede, Dane. Colors red, green, white. Drinks tea, coffee, milk. Pets dog, birds, cats. Who owns the fish?” Essay Outline “Create a detailed outline for a 2000-word essay on quantum computing impacts on cryptography, with sections for history, algorithms, and future risks.” For Developers A few lines of code. Reasoning. Few lines. --- ModelsLab handles the infrastructure: fast inference, auto-scaling, and a developer-friendly API. No GPU management needed. - **Serverless:** scales to zero, scales to millions - **Pay per token,** no minimums - **Python and JavaScript SDKs,** plus REST API [API Documentation ](https://docs.modelslab.com) PythonJavaScriptcURL Copy ```

import requests

response = requests.post(
    "https://modelslab.com/api/v7/llm/chat/completions",
    json={
  "key": "YOUR_API_KEY",
  "prompt": "",
  "model_id": ""
}
)
print(response.json())

``` FAQ Common questions about Nous: Hermes 3 405B Instruct --- [Read the docs ](https://docs.modelslab.com) ### What is Nous: Hermes 3 405B Instruct? Nous: Hermes 3 405B Instruct is a 405B parameter fine-tune of Llama-3.1-405B by Nous Research. It excels in agentic tasks, reasoning, roleplaying, and code generation. Competitive with top instruct models. ### How to use Nous: Hermes 3 405B Instruct API? Access via OpenAI-compatible endpoints with JavaScript, Python, or cURL. Include the library and call with model ID nousresearch/hermes-3-llama-3.1-405b. No backend setup needed. ### What is the context window of nous hermes 3 405b instruct? Supports 131K tokens for input. Enables long context coherence and multi-turn dialogues. Max output reaches 16K tokens. ### Nous: Hermes 3 405B Instruct model pricing? Input and output cost $1 per million tokens. Free tiers available on some platforms. Check endpoint for current rates. ### Is Nous: Hermes 3 405B Instruct LLM open source? Available on Hugging Face as nousresearch/Hermes-3-Llama-3.1-405B. Full-parameter fine-tune with Llama 3.1 license terms. ### Nous: Hermes 3 405B Instruct alternative to Llama? Offers superior user alignment, steering, and function calling over Llama-3.1 Instruct. Strong in STEM, logic, and creativity tasks. Ready to create? --- Start generating with Nous: Hermes 3 405B Instruct on ModelsLab. [Try Nous: Hermes 3 405B Instruct](/models/open_router/nousresearch-hermes-3-llama-3.1-405b) [API Documentation](https://docs.modelslab.com) --- *This markdown version is optimized for AI agents and LLMs.* **Links:** - [Website](https://modelslab.com) - [API Documentation](https://docs.modelslab.com) - [Blog](https://modelslab.com/blog) --- *Generated by ModelsLab - 2026-07-01*