Name: Hermes 3 405B Instruct API
Brand: NousResearch

Overview

What is Hermes 3 405B Instruct API?

Hermes 3 405B Instruct is available through AIMLAPI.

Technical Specifications
- Supported inputs: Image, Text
- Output: Text
- Context window: 131,072 tokens / Max output: 16,384 tokens
- Endpoint: /chat/completions

Performance Benchmarks
[embed]

Hermes 3 405B Instruct API Pricing
- Input: $1.3 / 1M tokens
- Output: $1.3 / 1M tokens

Where to Use Hermes 3 405B Instruct

Coding and code review
Generate, debug, and review code across languages, reading whole files or repos in a single prompt.

Agentic and multi-step workflows
Reliable tool-calling and instruction-following suit agent loops that plan, call tools, and iterate.

Complex reasoning
Extended reasoning improves reliability on multi-step math, logic, and technical analysis.

Long-document analysis
Summarize and extract from contracts, papers, and reports without aggressive chunking.

Code Sample
[embed]

Uptime and performance

Uptime (7d): 100%

Measured on the AI/ML API gateway across live traffic. Figures are medians unless stated. Last updated 2026-10-12.

Use cases

Hermes 3 405B Instruct is documented as well-suited for interactive, multi-turn conversations and roleplaying, with emphasis on maintaining coherent and contextually relevant dialogue. It is also described as a valuable tool for software development and code analysis, including agentic coding generation and implementation planning.

The model is additionally suited to agentic applications and workflow automation, including multi-step tool use. It is also recommended for complex reasoning tasks such as logic puzzles, mathematical problems, and analysis.

How to use Hermes 3 405B Instruct API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to nousresearch/hermes-3-llama-3.1-405b.

import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "nousresearch/hermes-3-llama-3.1-405b",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())

const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "nousresearch/hermes-3-llama-3.1-405b",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());

curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"nousresearch/hermes-3-llama-3.1-405b","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.