document management solution

 2) Google Workspace (Google Drive) via Drive API (.NET)

What this demo does

• Authenticates with a service account using domain-wide delegation

• Uploads a file to a Shared Drive / folder

• Sets metadata (name, description, custom properties)

• Shares the file (adds a permission)

• Lists revisions (versions)

Setup (once)

1. Create a Google Cloud project → Enable Drive API.

2. Create a Service Account, download the JSON key.

3. In Google Workspace Admin, grant Domain-wide delegation to the SA for scope:

   • https://www.googleapis.com/auth/drive

4. Share your target Shared Drive / folder with the service account or impersonate a user with access.

   • We’ll impersonate an admin/user via UserEmailToImpersonate.

NuGet

dotnet add package Google.Apis.Drive.v3
dotnet add package Google.Apis.Auth

Code (Console app)

using Google.Apis.Auth.OAuth2;
using Google.Apis.Drive.v3;
using Google.Apis.Services;
using Google.Apis.Upload;

class GDriveDemo
{
    // === Fill these ===
    private const string ServiceAccountJsonPath = "C:\\keys\\my-sa.json";
    private const string UserEmailToImpersonate = "[email protected]"; // has Drive access
    private const string ParentFolderId = "YOUR_FOLDER_OR_SHARED_DRIVE_FOLDER_ID";

    static async Task Main()
    {
        var drive = await GetDriveService();

        // 1) Upload with metadata + custom properties
        var fileMeta = new Google.Apis.Drive.v3.Data.File
        {
            Name = $"Invoice_{DateTime.UtcNow:yyyyMMddHHmmss}.pdf",
            Parents = new[] { ParentFolderId },
            Description = "Invoice for Acme Corp",
            Properties = new Dictionary
            {
                { "InvoiceNumber", "INV-2025-00123" },
                { "Customer", "Acme Corp" }
            }
        };

        using var stream = new FileStream("C:\\temp\\sample.pdf", FileMode.Open, FileAccess.Read);
        var createReq = drive.Files.Create(fileMeta, stream, "application/pdf");
        createReq.Fields = "id, name, webViewLink";
        var progress = await createReq.UploadAsync();

        if (progress.Status != UploadStatus.Completed)
            throw new Exception($"Upload failed: {progress.Exception}");

        var created = createReq.ResponseBody!;
        Console.WriteLine($"Uploaded: {created.Name}, Id: {created.Id}, Link: {created.WebViewLink}");

        // 2) Add a viewer permission to a user (external/internal)
        var perm = new Google.Apis.Drive.v3.Data.Permission
        {
            Type = "user",
            Role = "reader",
            EmailAddress = "[email protected]"
        };
        var permReq = drive.Permissions.Create(perm, created.Id);
        permReq.SendNotificationEmail = false;
        await permReq.ExecuteAsync();
        Console.WriteLine("Permission granted.");

        // 3) List revisions (versions)
        var revs = await drive.Revisions.List(created.Id).ExecuteAsync();
        foreach (var r in revs.RevisionsValue ?? [])
        {
            Console.WriteLine($"Revision: {r.Id}, ModifiedTime: {r.ModifiedTime}");
        }
    }

    static async Task GetDriveService()
    {
        var scopes = new[] { DriveService.Scope.Drive };
        var sa = GoogleCredential.FromFile(ServiceAccountJsonPath)
                                 .CreateScoped(scopes)
                                 .CreateWithUser(UserEmailToImpersonate);

        return new DriveService(new BaseClientService.Initializer
        {
            HttpClientInitializer = sa,
            ApplicationName = "DMS Demo",
        });
    }
}

Notes

• Custom metadata on Drive is best stored in properties (key/value). For robust schemas, keep a parallel DB (SQL) and store the Drive fileId there.

• If using Shared Drives, ensure the impersonated user has access to that drive and supportsAllDrives=true on certain calls (if needed).

Choosing Between M365 & Google

• Need tight records management, retention, Power Automate workflows → SharePoint/Graph is usually stronger.

• Need cross-platform simple storage/sharing with lightweight metadata → Drive API is quick to wire up.

 1) Microsoft 365 (SharePoint/OneDrive) via Microsoft Graph

What this demo does

• Authenticates app-only (daemon) with Azure AD

• Uploads a file to a SharePoint Document Library folder

• Writes metadata (columns) to the associated ListItem

• Reads version history

Setup (once)

1. Register an app in Entra ID (Azure AD):

   • Authentication: Application (client credentials).

   • API permissions (Application): Sites.ReadWrite.All, Files.ReadWrite.All (grant admin consent).

   • Get: Tenant ID, Client ID, Client Secret.

2. Find your Site ID and Drive ID (document library). Easiest: open the library in SharePoint → Graph Explorer can reveal IDs, or use the sites?search= endpoint once.

NuGet

dotnet add package Azure.Identity
dotnet add package Microsoft.Graph

Code (Console app)

Notes

• Create your custom columns in the document library first (same internal names used in FieldValueSet).

• For approvals, wire a Power Automate flow to the library and trigger on create/update, or call a flow HTTP endpoint from C# (p zremium connector) to start approvals programmatically.