TOOL LLM for API calls is a revolutionary AI tool that has been developed by a collaboration of prestigious universities and tech companies. This tool is not associated with Meta or Microsoft, contrary to popular belief. It’s an open-source model that has been fine-tuned using ChatGPT to perform API calls. The TOOL LLM is designed to enhance the reasoning capability of Language Models by using a decision tree algorithm called Adapt First. This algorithm evaluates multiple reasoning traces to find the best solution path. The TOOL LLM has shown comparable performance to ChatGPT and is expected to significantly improve tool use capability in open-source Language Models. The data sources for this tool include the Rapid API Hub, and a fine-tuning dataset created using ChatGPT. This tool represents a significant milestone in the field of AI and is expected to have far-reaching implications in various sectors.