Function-Calling Open Models (Hermes, Functionary)
Most base open models can't tool-call well — Hermes and Functionary are fine-tuned for it.
Base Models Cannot Tool-Call Reliably
Vanilla Llama, Mistral, or Qwen base models can be prompted to "return JSON like {...}" but often produce malformed output, miss arguments, or hallucinate tools.
Function-calling fine-tunes solve this.
Hermes Family
NousResearch Hermes models are top-tier function-calling fine-tunes:
- Hermes 3 Llama 3.1 8B / 70B
- Strong tool-call accuracy
- Apache-style permissive license
All lessons in this course
- Llama, Mistral and Qwen Overview
- Running Local Models with Ollama and llama.cpp
- Function-Calling Open Models (Hermes, Functionary)
- Trade-offs: Latency, Cost, Capability