The Java SDK’s JSON helpers do not encode multipart uploads. Use Java’s standard HTTP client to send the file bytes as shown below.
audio.mp3 in the working directory.
import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse.BodyHandlers;
import java.nio.file.Path;
import java.time.Duration;
import java.util.UUID;
String baseUrl = System.getenv().getOrDefault("PHASEO_BASE_URL", "https://api.phaseo.app/v1")
.replaceAll("/+$", "");
String apiKey = System.getenv("PHASEO_API_KEY");
String boundary = "phaseo-" + UUID.randomUUID();
var body = BodyPublishers.concat(
BodyPublishers.ofString("--" + boundary + "\r\nContent-Disposition: form-data; name=\"model\"\r\n\r\nopenai/whisper-1\r\n"),
BodyPublishers.ofString("--" + boundary + "\r\nContent-Disposition: form-data; name=\"file\"; filename=\"audio.mp3\"\r\nContent-Type: audio/mpeg\r\n\r\n"),
BodyPublishers.ofFile(Path.of("audio.mp3")),
BodyPublishers.ofString("\r\n--" + boundary + "--\r\n")
);
var request = HttpRequest.newBuilder(URI.create(baseUrl + "/audio/transcriptions"))
.header("Authorization", "Bearer " + apiKey)
.header("Content-Type", "multipart/form-data; boundary=" + boundary)
.timeout(Duration.ofSeconds(60))
.POST(body)
.build();
var response = HttpClient.newHttpClient().send(request, BodyHandlers.ofString());
if (response.statusCode() < 200 || response.statusCode() >= 300) {
throw new IOException("HTTP " + response.statusCode() + ": " + response.body());
}
System.out.println(response.body());