HumanLayer provides an API and SDK that allows AI agents to engage with humans for feedback, input, and approvals. It ensures that critical function calls are monitored by human oversight through approval workflows that operate across platforms like Slack and email. By seamlessly integrating with your favorite Large Language Model (LLM) and various frameworks, HumanLayer equips AI agents with secure access to external information. The platform is compatible with numerous frameworks and LLMs, such as LangChain, CrewAI, ControlFlow, LlamaIndex, Haystack, OpenAI, Claude, Llama3.1, Mistral, Gemini, and Cohere. Key features include structured approval workflows, integration of human input as a tool, and tailored responses that can escalate as needed. It enables the pre-filling of response prompts for more fluid interactions between humans and agents. Additionally, users can direct requests to specific individuals or teams and manage which users have the authority to approve or reply to LLM inquiries. By allowing the flow of control to shift from human-initiated to agent-initiated, HumanLayer enhances the versatility of AI interactions. Furthermore, the platform allows for the incorporation of multiple human communication channels into your agent's toolkit, thereby expanding the range of user engagement options.