What is Open Weights Model?
An open-weights model is an AI model whose trained parameters are publicly released, allowing anyone to download, run, fine-tune, and deploy it — distinct from fully open-source models which also release training code and data.
WHY IT MATTERS
Open-weights models (Llama, Mistral, Qwen) have democratized AI. Instead of relying on API providers, developers can run models locally, customize them for specific domains, and deploy without per-token costs.
The 'open weights' distinction matters: Meta's Llama releases model weights under a license, but not the training code, data, or full methodology. This gives users deployment freedom without full reproducibility.
For agent builders, open-weights models offer: cost control (no API fees at scale), privacy (data never leaves your infrastructure), customization (fine-tune for your domain), and independence (no vendor lock-in).