HumanLayer is an API and SDK that enables AI agents to reach out to humans for feedback, input, and approval. It ensures human oversight on high-risk function calls through approval workflows across channels like Slack and email, securely connecting your chosen LLMs and frameworks with AI agents. Backed by Y Combinator, HumanLayer is compatible with various popular frameworks and LLMs, including OpenAI, Claude, and Llama 3.1. It provides a platform that enhances AI agents' capabilities through a human-in-the-loop approach, increasing their reliability and efficiency. HumanLayer offers a pricing strategy that includes free, paid, and custom enterprise plans to meet diverse user needs.