Hermes 4 405B
Nous's Hermes 4 405B is a chat model. 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...
by Nous · 131K token context window
Best for
- low-latency chat and routing
- request routing and triage
- text classification
Ways to use Hermes 4 405B in osFoundry
Connect with your own key (BYOK)
Open the key dialog and paste your Nous API key. osFoundry discovers Hermes 4 405B automatically — assign it to a Maestro role (router, direct, orchestrator, or fallback) in the Pipeline tab and it is live in every chat. Your key, your provider account — no token markup.
Use it in a Room App
Room Apps declare AI features in their manifest, then call them with invokeAI:
import { invokeAI } from '@osfoundry/app-sdk'
// 'summarize' is an AI feature declared in your app manifest.
const result = await invokeAI('summarize', userText)
Call it from your own apps
Once a model is wired into your workspace you can host it as an API and reach it from your own services, scripts, or CI — outside osFoundry.
Run Hermes 4 405B yourself
Hermes 4 405B is also available as open weights — self-host it for full data control and no per-token cost. See that page for GPU requirements and a cost comparison against API pricing.
Hermes 4 405B vs similar models
Licence
Hosted — usage subject to provider terms — Hosted-only model — usage governed by the provider's API terms. Bring your own provider key.
No weights distributed; usage subject to provider terms.
Frequently asked about Hermes 4 405B
How much does Hermes 4 405B cost?
Hermes 4 405B is metered at $ 1.00 /1M for input, and $ 3.00 /1M for output. Bring your own Nous API key — osFoundry passes through provider pricing without markup.
Can I use Hermes 4 405B commercially?
Commercial use is allowed with conditions. Hosted-only model — usage governed by the provider's API terms. Bring your own provider key. No weights distributed; usage subject to provider terms.
What is the context window of Hermes 4 405B?
Hermes 4 405B supports a 131K token context window.
Can I run Hermes 4 405B locally?
No — Hermes 4 405B is hosted only and accessed via the Nous API. An open-weights equivalent is available to self-host — see the cross-link above.
What is Hermes 4 405B best at?
Hermes 4 405B is well-suited to low-latency chat and routing, request routing and triage, text classification.
How do I use Hermes 4 405B in osFoundry?
Paste your Nous API key in the key dialog (or deploy the open weights for self-hostable models), assign Hermes 4 405B to a Maestro role in the Pipeline tab, then use it in chat, Room Apps via invokeAI, or your own apps.
Published by Nous on August 26, 2025. Source: https://openrouter.ai/nousresearch/hermes-4-405b