Hi there,
I’m facing an issue regarding the generation of JSON Schema used as value of GenerationConfig.ResponseSchema given the following scenario. The class is defined like this
class Recipe {
public string Name { get; set; }
}
Which is then passed into the property as a list / array in order to retrieve multiple suggestions from the Gemini API.
var generationConfig = new GenerationConfig()
{
ResponseMimeType = "application/json",
ResponseSchema = new List<Recipe>()
};
The generated output looks like this
{
"model" : "models/gemini-1.5-pro-latest",
"contents" : [ {
"role" : "user",
"parts" : [ {
"text" : "List a few popular cookie recipes."
} ]
} ],
"generationConfig" : {
"responseMimeType" : "application/json",
"responseSchema" : {
"type" : "array",
"items" : {
"type" : "object",
"properties" : {
"name" : {
"type" : [ "string", "null" ]
}
},
"required" : [ "name" ]
}
}
}
}
Specifying the property Name as a nullable string. This is conform with the specs of type according to JSON Schema - Type-specific keywords allowing instances that can be of multiple primitive types.
The type keyword may either be a string or an array:
** If it’s a string, it is the name of one of the basic types above.*
** If it is an array, it must be an array of strings, where each string is the name of one of the basic types, and each element is unique. In this case, the JSON snippet is valid if it matches any of the given types.*
See also JSON Schema: A Media Type for Describing JSON Documents and following paragraphs.
Currently, the Gemini API returns an HTTP 400 Bad Request with this information.
{
"error": {
"code": 400,
"message": "Invalid JSON payload received. Unknown name \"type\" at 'generation_config.response_schema.items.properties[0].value': Proto field is not repeating, cannot start list.\nInvalid JSON payload received. Unknown name \"type\" at 'generation_config.response_schema.items.properties[1].value': Proto field is not repeating, cannot start list.",
"status": "INVALID_ARGUMENT",
"details": [
{
"@type": "type.googleapis.com/google.rpc.BadRequest",
"fieldViolations": [
{
"field": "generation_config.response_schema.items.properties[0].value",
"description": "Invalid JSON payload received. Unknown name \"type\" at 'generation_config.response_schema.items.properties[0].value': Proto field is not repeating, cannot start list."
},
{
"field": "generation_config.response_schema.items.properties[1].value",
"description": "Invalid JSON payload received. Unknown name \"type\" at 'generation_config.response_schema.items.properties[1].value': Proto field is not repeating, cannot start list."
}
]
}
]
}
}
Indicating that the value of type cannot be a list/array of primitives types.
This doesn’t align with the specs of JSON Schema.
Changing the type value to a single primitive type returns an HTTP 200 OK.
{
"model" : "models/gemini-1.5-pro-latest",
"contents" : [ {
"role" : "user",
"parts" : [ {
"text" : "List a few popular cookie recipes."
} ]
} ],
"generationConfig" : {
"responseMimeType" : "application/json",
"responseSchema" : {
"type" : "array",
"items" : {
"type" : "object",
"properties" : {
"name" : {
"type" : "string"
}
}
}
}
}
}
and the result as expected.
{
"candidates" : [ {
"content" : {
"parts" : [ {
"text" : "[{\"name\": \"Chocolate Chip Cookies\"}, {\"name\": \"Peanut Butter Cookies\"}, {\"name\": \"Oatmeal Raisin Cookies\"}, {\"name\": \"Snickerdoodles\"}, {\"name\": \"Shortbread Cookies\"}]"
} ],
"role" : "model"
},
"finishReason" : "STOP",
"avgLogprobs" : -0.009499770402908326
} ],
"usageMetadata" : {
"promptTokenCount" : 8,
"candidatesTokenCount" : 45,
"totalTokenCount" : 53
},
"modelVersion" : "gemini-1.5-pro-002"
}
Someone else observing this issue?
Right now, this seems to be an issue with the Gemini API not accepting a conforming JSON Schema with multiple primitive types as the type definition of a property.
Assistance please. Thanks.
Cheers, JoKi
