Android™

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.

Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    success = false;

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

    CkAi ai = new CkAi();

    // 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.put_Provider("openai");

    // Use your provider's API key.
    ai.put_ApiKey("MY_API_KEY");

    // Choose a model.
    ai.put_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.
    String file_id = "file-5G2xncrEiHbVfYPRpFgP9c";
    ai.InputAddFileId(file_id,"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 == false) {
        Log.i(TAG, ai.lastErrorText());
        return;
        }

    // Get the text response.
    CkStringBuilder sbResponse = new CkStringBuilder();
    ai.GetOutputTextSb(sbResponse);
    Log.i(TAG, sbResponse.getAsString());

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}