Getting Structured Response Format to Work with OpenAI Models

Kyllian Vinkler · 2025-09-18 08:06:19.556851+00

Hi guys! Has anyone managed to get the `Structured response format` working ? It's an option of the `openAI` models that permits to ask for a specific json format for the response, but it seems completely ignored by Dust :confused:

Getting Structured Response Format to Work with OpenAI Models | Dust Community

9 comments

· Sorted by Oldest

Greyg Sinigaglia de Malibran
·
·
it’s working on my side, what is your issue ?
Charly Leporc
·
·
Working on my side also if the structured format is described in the prompt
Kyllian Vinkler
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·
I noticed that as well, if I describe it in the prompt it's better, but I still get it returned as a string starting by : " ```json myJson ``` " And sometimes the return doesn't respect at all the keys (new invented keys are added). I'm used to the native sdk of openAI that returns a real json (not in a string) and really respect the schema, but here I couldn't have something similar

Greyg Sinigaglia de Malibran

Example of one of my Structured Response Format that is working 100% of the time (only available on openAI models): If it can help

{
  "type": "json_schema",
  "json_schema": {
    "name": "categoryAnswerabilitySchema",
    "strict": true,
    "schema": {
      "type": "object",
      "properties": {
        "category": {
          "type": "string",
          "description": "Must be the exact parent category from the reference data"
        },
        "subcategory": {
          "type": "string",
          "description": "Must be a subcategory that belongs to the specified category"
        },
        "ai_answerable": {
          "type": "boolean",
          "description": "Indicates if the subcategory is answerable by AI"
        }
      },
      "required": ["category", "subcategory", "ai_answerable"],
      "additionalProperties": false
    }
  }
}

Kyllian Vinkler
·
·
Thank you for the example! Are you mentioning something specific in the prompt in order to follow this schema ? Are you getting the response in a real JSON or in a string that you need to parse (for me I get that in the content field of the response)
Greyg Sinigaglia de Malibran
·
·
Kyllian Vinkler I do a JSON.parse() of the content

Greyg Sinigaglia de Malibran

Indeed, in the prompt in case of:

OUTPUT FORMAT:
You must return a JSON object with the following structure:
{
"category": "string", // Must be the exact parent category from the reference data
"subcategory": "string", // Must be a subcategory that belongs to the specified category
"ai_answerable": boolean
}

Kyllian Vinkler
·
·
Ok thanks! I talked with the support and apparently GPT-5 isn't really following the json properly all the time so it should be better with previous models
Tomas
·
·
I noticed the same, GPT-5 ignored it multiple times, but the 4point models are consistent & sufficient

Loading comments

Greyg Sinigaglia de Malibran
·
·
it’s working on my side, what is your issue ?
Charly Leporc
·
·
Working on my side also if the structured format is described in the prompt
Kyllian Vinkler
·
·
I noticed that as well, if I describe it in the prompt it's better, but I still get it returned as a string starting by : " ```json myJson ``` " And sometimes the return doesn't respect at all the keys (new invented keys are added). I'm used to the native sdk of openAI that returns a real json (not in a string) and really respect the schema, but here I couldn't have something similar

Greyg Sinigaglia de Malibran

Example of one of my Structured Response Format that is working 100% of the time (only available on openAI models): If it can help

{
  "type": "json_schema",
  "json_schema": {
    "name": "categoryAnswerabilitySchema",
    "strict": true,
    "schema": {
      "type": "object",
      "properties": {
        "category": {
          "type": "string",
          "description": "Must be the exact parent category from the reference data"
        },
        "subcategory": {
          "type": "string",
          "description": "Must be a subcategory that belongs to the specified category"
        },
        "ai_answerable": {
          "type": "boolean",
          "description": "Indicates if the subcategory is answerable by AI"
        }
      },
      "required": ["category", "subcategory", "ai_answerable"],
      "additionalProperties": false
    }
  }
}

Kyllian Vinkler
·
·
Thank you for the example! Are you mentioning something specific in the prompt in order to follow this schema ? Are you getting the response in a real JSON or in a string that you need to parse (for me I get that in the content field of the response)
Greyg Sinigaglia de Malibran
·
·
Kyllian Vinkler I do a JSON.parse() of the content

Greyg Sinigaglia de Malibran

Indeed, in the prompt in case of:

OUTPUT FORMAT:
You must return a JSON object with the following structure:
{
"category": "string", // Must be the exact parent category from the reference data
"subcategory": "string", // Must be a subcategory that belongs to the specified category
"ai_answerable": boolean
}

Kyllian Vinkler
·
·
Ok thanks! I talked with the support and apparently GPT-5 isn't really following the json properly all the time so it should be better with previous models
Tomas
·
·
I noticed the same, GPT-5 ignored it multiple times, but the 4point models are consistent & sufficient