When Claude wants to run code, you need a webhook it can call. Most teams slam together a Lambda URL, but that skips critical security and versioning features. Learn how API Gateway + Lambda gives you a production‑grade, type‑safe bridge for Claude’s function calls.

What is Claude Function Calling?

Claude (or any large language model, LLM) can generate a piece of JSON that describes “I want to call a function named addUser with these arguments”.

function calling is the process where the model sends that JSON to a webhook – an HTTP endpoint you control – and you turn the JSON into real work (e.g., a database write).

Key terms