The JavaScript Object Notation (JSON) file and data interchange format is an industry-standard because it is both easily readable by humans and parsable by machines.
However, large language models (LLMs) notoriously struggle with JSON — they might hallucinate, create wonky responses that only partially adhere to instructions or fail to parse completely. This often requires developers to use workarounds such as open-source tooling, many different prompts or repeated requests to ensure output interoperability.
Now, OpenAI is helping ease these frustrations with the release of its Structured Outputs in the API. Released today, the functionality helps ensure that model-generated outputs match JSON Schemas. These schemas are critical because they describe content, structure, types of data and expected constraints in a given JSON document.
OpenAI says it is the No. 1 feature developers have been asking for because it allows for consistency across various applications. OpenAI CEO Sam Altman posted on X today that the release is by “very popular demand.”
The company said that its evaluations with Structured Outputs on its new GPT-4o scores a “perfect 100%.”
The new feature announcement comes on the heels of quite a bit of excitement at OpenAI this week: Three key executives — John Schulman, Greg Brockman and Peter Deng — suddenly each announced their departure, and Elon Musk is yet again suing the company, calling the betrayal of their AI mission “Shakespearian.”
Easily ensuring schema adherence
JSON is a text-based format for storing and exchanging data. It has become one of the most popular data formats among developers because it is simple, flexible and compatible with various programming languages. OpenAI quickly met demand from developers when it released its JSON mode on its models at last year’s DevDay.
With Structured Outputs in the API, developers can constrain OpenAI models to match schemas. OpenAI says the feature also allows its models to better understand more complicated schemas.
“Structured Outputs is the evolution of JSON mode,” the company writes on its blog. “While both ensure valid JSON is produced, only Structured Outputs ensure schema adherence.” This means that developers “don’t need to worry about the model omitting a required key, or hallucinating an invalid enum value.” (Enumeration value is a process that names constants in language, making code easier to read and maintain).
Developers can ask Structured Outputs to generate an answer in a step-by-step way to guide through to the intended output. According to OpenAI, developers don’t need to validate or retry incorrectly formatted responses, and the feature allows for simpler prompting while providing explicit refusals.
“Safety is a top priority for OpenAI — the new Structured Outputs functionality will abide by our existing safety policies and will still allow the model to refuse an unsafe request,” the company writes.
Structured Outputs is available on GPT-4o-mini, GPT-4o and fine-tuned versions of these models, and can be used on the Chat Completions API, Assistants API and Batch API, and it is also compatible with vision inputs.
OpenAI emphasizes that the new functionality “takes inspiration from excellent work from the open source community: namely, the outlines, jsonformer, instructor, guidance and lark libraries.”
Author: Taryn Plumb
Source: Venturebeat
Reviewed By: Editorial Team
