The Best C# API for Shipping Container OCR

// Get 200 free credits:
// 👉 https://structocr.com/register

using System;
using System.IO;
using System.Net.Http;
using System.Text.Json;
using System.Threading.Tasks;

public class ContainerOcrExample
{
    public static async Task Main(string[] args)
    {
        string apiKey = "YOUR_API_KEY"; // Replace with your actual API key
        string imagePath = "path/to/your/container_image.jpg"; // Replace with the path to your container image

        try
        {
            Console.WriteLine($"Reading image from {imagePath}...");

            // 1. Open the file stream directly for efficient upload
            using var fileStream = File.OpenRead(imagePath);
            using var streamContent = new StreamContent(fileStream);
            streamContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");

            // 2. Configure the HTTP client
            using var httpClient = new HttpClient();
            httpClient.DefaultRequestHeaders.Add("x-api-key", apiKey);
            httpClient.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

            Console.WriteLine("Uploading to StructOCR API...");

            // 3. Send the POST request (Direct File Upload)
            HttpResponseMessage response = await httpClient.PostAsync("https://api.structocr.com/v1/container", streamContent);

            // 4. Handle the response
            if (response.IsSuccessStatusCode)
            {
                string responseBody = await response.Content.ReadAsStringAsync();

                // Parse the JSON response
                using (JsonDocument document = JsonDocument.Parse(responseBody))
                {
                    JsonElement root = document.RootElement;

                    if (root.GetProperty("success").GetBoolean())
                    {
                        JsonElement data = root.GetProperty("data");
                        Console.WriteLine("\n✅ Extraction Successful!");
                        Console.WriteLine($"Container Number: {data.GetProperty("container_number").GetString()}");
                        Console.WriteLine($"Is Valid (ISO 6346): {data.GetProperty("is_valid").GetBoolean()}");
                        Console.WriteLine($"Confidence: {data.GetProperty("confidence").GetString()}\n");

                        if (data.TryGetProperty("parsed", out JsonElement parsed))
                        {
                            Console.WriteLine("--- Parsed Details ---");
                            Console.WriteLine($"Owner Code: {parsed.GetProperty("owner_code").GetString()}");
                            Console.WriteLine($"Category: {parsed.GetProperty("category").GetString()}");
                            Console.WriteLine($"Serial Number: {parsed.GetProperty("serial_number").GetString()}");
                            Console.WriteLine($"Check Digit: {parsed.GetProperty("check_digit").GetString()}");
                        }
                    }
                    else
                    {
                        Console.WriteLine($"❌ API Error: {root.GetProperty("error").GetString()}");
                    }
                }
            }
            else
            {
                Console.WriteLine($"❌ HTTP Error: Status Code {response.StatusCode}");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Exception: {ex.Message}");
        }
    }
}