Council is an open-source platform for rapidly developing customized generative AI applications using collaborating ‘agents’. The platform enables the robust deployment and monitoring of generative AI models ensuring they can be operated with confidence and accuracy. Council helps developers create sophisticated agents for tasks like customer service, self-service analytics, code generation and marketing with predictable behavior by leveraging its powerful approach to control flow using Controllers, Filters, Evaluators and Budgets for agents. This allows the automated routing between agents, comparing, evaluating and selecting the best results for a (sub-)task. It extends the LLM tool ecosystem and integrates with a wide variety of Large Language Models (LLMs) like GPT-4, Llama 2, and Claude 2 to unlock generative AI for business applications.