LangMart: Nous: Hermes 4 405B

Model Overview

Property	Value
Model ID	`openrouter/nousresearch/hermes-4-405b`
Name	Nous: Hermes 4 405B
Provider	nousresearch
Released	2025-08-26

Description

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 ... traces or respond directly, offering flexibility between speed and depth. Users can control the reasoning behaviour with the reasoning enabled boolean. Learn more in our docs

The model is instruction-tuned with an expanded post-training corpus (~60B tokens) emphasizing reasoning traces, improving performance in math, code, STEM, and logical reasoning, while retaining broad assistant utility. It also supports structured outputs, including JSON mode, schema adherence, function calling, and tool use. Hermes 4 is trained for steerability, lower refusal rates, and alignment toward neutral, user-directed behavior.

Description

LangMart: Nous: Hermes 4 405B is a language model provided by nousresearch. This model offers advanced capabilities for natural language processing tasks.

Provider

nousresearch

Specifications

Spec	Value
Context Window	131,072 tokens
Modalities	text->text
Input Modalities	text
Output Modalities	text

Pricing

Type	Price
Input	$0.30 per 1M tokens
Output	$1.20 per 1M tokens

Capabilities

Frequency penalty
Include reasoning
Max tokens
Presence penalty
Reasoning
Repetition penalty
Response format
Seed
Stop
Structured outputs
Temperature
Tool choice
Tools
Top k
Top p

Detailed Analysis

Nous Research: Hermes 4 405B