# Event streaming in OpenAPI 3.2: What changed and why it matters

DevFeed: [Event streaming in OpenAPI 3.2: What changed and why it matters](<https://devfeed.tech/articles/event-streaming-in-openapi-3-2-what-changed-and-why-it-matters-30956.md>)

Original publisher: [Read original article](<https://developerhub.io/blog/event-streaming-in-openapi-3-2-what-changed-and-why-it-matters/>)

Author: Zaid Daba'een

Published: 2025-10-06T08:47:55Z

Content type: tutorial

Language: en

Sources: [DeveloperHub.io](<https://devfeed.tech/sources/developerhub-io.md>)

Topics: [OpenAPI Specification](<https://devfeed.tech/topics/openapi.md>), [Streaming](<https://devfeed.tech/topics/streaming.md>), [Event-Streaming](<https://devfeed.tech/topics/event-streaming.md>), [Large Language Model](<https://devfeed.tech/topics/llm.md>), [API](<https://devfeed.tech/topics/api.md>), [JSON](<https://devfeed.tech/topics/json.md>)

Tags: [api](<https://devfeed.tech/tags/api.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [event-streaming](<https://devfeed.tech/tags/event-streaming.md>), [json](<https://devfeed.tech/tags/json.md>), [llms](<https://devfeed.tech/tags/llms.md>), [openapi](<https://devfeed.tech/tags/openapi.md>), [streaming](<https://devfeed.tech/tags/streaming.md>)

## AI overview

This tutorial explains how OpenAPI 3.2 describes event-streaming APIs using sequential media types and the itemSchema field to define each streamed event. It covers SSE, JSON Lines, JSON Sequences, and multipart responses, with examples for LLM token streaming and guidance on termination and event modeling.

## Source excerpt

OpenAPI 3.2 brings first-class event streaming with sequential media types and an itemSchema for each event. Document SSE or JSONL streams clearly--ideal for LLMs that stream tokens, optional summaries, and a deterministic "[DONE]" sentinel to end the stream.