Nous: Hermes 4 405B✓ Catalog verified
Hermes 4 is a large-scale reasoning model built on Meta-Llama-3.1-405B and released by Nous Research. It introduces a hybrid reasoning mode, where the model can choose to deliberate internally with...
Overview
Hermes 4 is a large-scale reasoning model built on Meta-Llama-3.1-405B and released by Nous Research. It introduces a hybrid reasoning mode, where the model can choose to deliberate internally with...
Access: available through the official Nousresearch API. Context window: 131K.
Specifications
| API identifier | nousresearch/hermes-4-405b |
| Provider | Nousresearch |
| Model type | Text LLM |
| Context window | 131K catalog |
| Input modalities | text |
| Output modalities | text |
| Released | Aug 26, 2025 |
| Moderated | No |
| Architecture modality | text->text |
Pricing
Live pricing components for nousresearch/hermes-4-405b as published in the catalog.
| Pricing component | Raw unit price | Normalized | Unit |
|---|---|---|---|
| Prompt tokens | $0.000001 | $1.00 / 1M | Per input token |
| Completion tokens | $0.000003 | $3.00 / 1M | Per output token |
| Request fee | N/A | N/A | Per request |
| Image fee | N/A | N/A | Per image unit |
| Web search fee | N/A | N/A | Per search request |
Cost calculator
Estimate monthly spend from your own token volumes.
Estimated Total Cost
$1.1Calculated from current list pricing in the ModelsAtlas catalog.Capabilities
| Capability | Status | What it means |
|---|---|---|
| Visual Understanding | Not advertised | Image and document analysis support |
| Audio Processing | Not advertised | Speech and voice aligned flows |
| Tool Calling | Not advertised | Supports tools / function calling |
| Self-Hosting | Not advertised | Deploy outside managed APIs |
Capability signals
Directional signals derived from model metadata and capability tags — not official benchmark submissions.
Quick start
Call Nous: Hermes 4 405B through an OpenAI-compatible client.
from openai import OpenAI
client = OpenAI(
base_url="https://openrouter.ai/api/v1",
api_key="YOUR_API_KEY"
)
response = client.chat.completions.create(
model="nousresearch/hermes-4-405b",
messages=[{"role": "user", "content": "Explain quantum physics."}]
)
print(response.choices[0].message.content)Alternatives
Closest models by context window from a different provider.
| Model | Provider | Context | Input /1M | Actions |
|---|---|---|---|---|
| AionLabs: Aion-1.0 | Aion Labs | 131K | $4.00 | View → |
| AionLabs: Aion-1.0-Mini | Aion Labs | 131K | $0.70 | View → |
Sources & attribution
Pricing and metadata are maintained in the ModelsAtlas catalog.
Frequently asked questions
How much does Nous: Hermes 4 405B cost?
$1.00 per 1M input tokens and $3.00 per 1M output tokens on the official Nousresearch API.
What is the context window of Nous: Hermes 4 405B?
Nous: Hermes 4 405B supports up to 131K tokens of context.
Does Nous: Hermes 4 405B support tool / function calling?
Nous: Hermes 4 405B does not advertise first-class tool/function calling. Check vendor docs for the latest capabilities.
How do I access Nous: Hermes 4 405B?
Use the official Nousresearch API with the model id `nousresearch/hermes-4-405b`. See the Quick start section above for code examples.