标签：#sns

LLMs can now call tools, but turning their output into a trustworthy event stream is still a puzzle. We wire Claude’s function‑calling to an SNS FIFO topic, giving you ordered, deduplicated notifications that downstream Lambda functions can consume with zero‑loss guarantees. Why SNS FIFO Is a Good Fit for LLM‑Generated Events When an LLM decides to “publishAlert”, you usually want the alert to be processed exactly in the order it was generated . Imagine a fire‑alarm system that first warns about a smoke detector, then follows up with a sprinkler‑activation command. If those two messages arrive swapped, you could end up turning on sprinklers before the fire is even confirmed. FIFO stands for First‑In‑First‑Out . An SNS FIFO topic guarantees that messages sharing the same MessageGroupId are delivered to subscribers in the exact order they were published. This is different from the default “standard” SNS topics, which deliver messages quickly but without ordering guarantees. In plain English: SNS FIFO is like a single‑lane road with a traffic light that lets cars (messages) pass one after another, never overtaking. Key terms (first use) Term Meaning Function calling A feature where the LLM can invoke a pre‑defined tool (a piece of code) instead of just returning text. FIFO topic An SNS topic that preserves the order of messages that belong to the same logical group. MessageGroupId An identifier that tells SNS which messages belong together for ordering. MessageDeduplicationId A token that prevents the same message from being delivered twice within a 5‑minute window. Lambda A serverless compute service that runs code in response to events (like an SNS message). Because the LLM can generate many alerts rapidly, using a FIFO topic means you can treat the AI as a deterministic producer rather than a chaotic chatterbox. The downstream Lambda sees the alerts in the same sequence the model emitted them. Setting Up Claude’s Function Calls to Publish to SNS Before you can send