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Objective-C

Referencing a Pre-Uploaded File by file_id in an AI Request

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Some AI proviers have a Files API that lets you upload content once and then reference it later in generation requests using a file_id. This is especially useful for large documents, reuse across multiple prompts, or keeping inputs structured and separate from your prompt text.

This example demonstrates how to use a file_id in a request.

Chilkat Objective-C Downloads

Objective-C
#import <CkoAi.h>
#import <NSString.h>
#import <CkoStringBuilder.h>

BOOL success = NO;

success = NO;

//  This example assumes the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

CkoAi *ai = [[CkoAi alloc] init];

//  The provider can be "openai", "google", "claude", "mistral", "deepseek", "xai", or any provider
//  that supports referencing pre-uploaded files by a file_id (or file uri).
ai.Provider = @"openai";

//  Use your provider's API key.
ai.ApiKey = @"MY_API_KEY";

//  Choose a model.
ai.Model = @"gpt-5-mini";

//  See the following example showing how to upload a file
//  Upload a File to an AI Provider (OpenAI, Google, Antropic, X)

//  Use the file_id of the pre-uploaded file.
NSString *file_id = @"file-5G2xncrEiHbVfYPRpFgP9c";
[ai InputAddFileId: file_id mime_type: @"application/json"];

[ai InputAddText: @"Explain why Hamlet delays taking revenge, using only evidence from the file."];

//  Ask the AI for text output.
success = [ai Ask: @"text"];
if (success == NO) {
    NSLog(@"%@",ai.LastErrorText);
    return;
}

//  Get the text response.
CkoStringBuilder *sbResponse = [[CkoStringBuilder alloc] init];
[ai GetOutputTextSb: sbResponse];
NSLog(@"%@",[sbResponse GetAsString]);