Function Calling

Function calling lets an AI model request that an application run a specific operation, such as searching data, checking a value, or invoking an external service. The model typically returns a tool name and arguments in a defined format; the application validates the request, performs the operation, and can provide the result for a follow-up response. This approach connects language models to current information and software capabilities while keeping execution under application control.

Open source tools in this area include libraries for defining callable functions, validating arguments, routing requests, and coordinating tool use across agents or services. When choosing one, consider supported model interfaces, schema and validation features, security controls, documentation, maintenance activity, license, and integration requirements. These tools are useful to developers building assistants, automation, and data workflows that need reliable interaction with existing systems.