Gemini Structured Outputs
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Gemini | Structured Outputs

Gemini can return responses in structured JSON format conforming to a schema you define. This guarantees valid, parseable JSON output matching your schema definition.

Simple Example

Use the convenience method to create content with JSON schema output.


Gemini := TsgcHTTP_API_Gemini.Create(nil);
Gemini.GeminiOptions.ApiKey := 'API_KEY';

vSchema := '{"type":"object","properties":{"name":{"type":"string"},' +
  '"age":{"type":"integer"}},"required":["name","age"]}';

WriteLn(Gemini._CreateContentJSON('gemini-2.0-flash',
  'Extract the name and age: John is 30 years old.', vSchema));

Advanced Example

Use the typed classes to configure structured output with ResponseMimeType and ResponseSchema.


Gemini := TsgcHTTP_API_Gemini.Create(nil);
Gemini.GeminiOptions.ApiKey := 'API_KEY';

oRequest := TsgcGeminiClass_Request_GenerateContent.Create;
Try
  oRequest.Model := 'gemini-2.0-flash';
  oRequest.MaxOutputTokens := 4096;
  oRequest.ResponseMimeType := 'application/json';
  oRequest.ResponseSchema :=
    '{"type":"object","properties":{"sentiment":{"type":"string"},' +
    '"confidence":{"type":"number"}},"required":["sentiment","confidence"]}';

  SetLength(oContents, 1);
  oContents[0] := TsgcGeminiClass_Request_Content.Create;
  oContents[0].Role := 'user';
  SetLength(oParts, 1);
  oParts[0] := TsgcGeminiClass_Request_Part.Create;
  oParts[0].Text := 'Analyze the sentiment: I love this product!';
  oContents[0].Parts := oParts;
  oRequest.Contents := oContents;

  oResponse := Gemini.CreateContent(oRequest);
  Try
    if Length(oResponse.Candidates) > 0 then
      if Length(oResponse.Candidates[0].Parts) > 0 then
        WriteLn(oResponse.Candidates[0].Parts[0].Text);
  Finally
    oResponse.Free;
  End;
Finally
  oParts[0].Free;
  oContents[0].Free;
  oRequest.Free;
End;

Properties