Hermes 4 405B
Hermes 4 405B is NousResearch's largest model in the Hermes series, built on a 405B open-weight base with Nous's own instruction-following fine-tune. The Hermes series is known for precise function calling, structured output adherence, and compliance with complex system prompt directives—qualities that scale up substantially at the 405B level.
At this scale, the model handles intricate multi-step reasoning, long-context document processing, and agentic task execution with high reliability. NousResearch targets developers building sophisticated pipelines where the model must reliably follow schemas, call tools correctly, and sustain coherent reasoning across large inputs—use cases where smaller Hermes variants may fall short.
Key Features
Precise instruction following and structured output compliance at massive scale
Reliable function calling and JSON schema adherence
Strong multi-step reasoning and chain-of-thought execution
Long-context document analysis and synthesis
Agentic pipeline support with consistent tool-use behavior
Open-weight availability for self-hosted deployments
Ideal Use Cases
Complex agentic workflows requiring reliable multi-tool orchestration
Enterprise document processing and structured data extraction
Code generation and technical task pipelines at high complexity
Research summarization across long source documents
Custom AI assistants built on open-weight infrastructure
Example Prompts for Hermes 4 405B
Technical Specifications
| Provider | NousResearch |
| Category | Text |
| Modality | Text -> Text |
Frequently Asked Questions
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