LTI Advantage Platform

A sample LTI 1.3 / LTI Advantage platform built with ASP.NET Core. It pairs with the LtiAdvantage libraries and demonstrates how to host the LTI Advantage services from a platform's perspective. There is a companion sample tool over at LtiAdvantageTool.

Supported features

• LTI 1.3 Core launch
  • Launch tools with or without a context (i.e. as an assignment or an admin tool), and as a teacher or a student.
• Assignment and Grade Services v2
  • Tools can list line items for a course, get a specific line item, read results, and post scores.
• Names and Role Provisioning Services v2
  • Tools can read course membership.
• Deep Linking 2.0
  • Tools can add LTI links to the platform or course.

Stack

This sample tracks the LtiAdvantage libraries' modernized stack:

• ASP.NET Core 10 (Razor Pages + MVC controllers).
• OpenIddict 7.x as the OpenID Connect / OAuth 2.0 server, replacing the earlier dependency on Duende / IdentityServer4.
• ASP.NET Core Identity for application user accounts.
• EF Core 10 with SQLite as the default database (cross-platform).
• LtiAdvantage, LtiAdvantage.AspNetCore, and LtiAdvantage.Oidc packages for the LTI message types, controller bases, and OpenIddict impersonation hook.

The sample takes the same architectural approach as before — each registered application user is a tenant with their own platform, course, and people — but the OIDC plumbing is now OpenIddict. See Program.cs for how the server, the LtiAdvantage impersonation handler, and the LTI claims event handler are wired together; the LTI claims handler appends id_token claims for resource-link and deep-linking launches.

Layout

/ (Visual Studio solution file)
└── src/
    ├── Program.cs (top-level Hosting + OpenIddict + LtiAdvantage setup)
    ├── Config.cs (LTI scopes registered with OpenIddict)
    ├── Areas/Identity/ (ASP.NET Core Identity user management; edit platform, course, and people)
    ├── Controllers/
    │   ├── AuthorizationController.cs (OIDC /connect/authorize + /connect/token endpoints)
    │   ├── LineItemsController.cs / ResultsController.cs / ScoresController.cs (AGS v2)
    │   └── MembershipController.cs (NRPS v2)
    ├── Data/ (EF Core entities and migrations)
    ├── Pages/
    │   ├── DeepLinks.cshtml (receives the deep-linking response)
    │   └── OidcLaunch.cshtml (initiates the LTI 1.3 launch by redirecting to the tool)
    ├── Utility/
    │   ├── LtiAdvantageClaimsHandler.cs (OpenIddict ProcessSignInContext handler that adds LTI claims)
    │   ├── ToolClientManager.cs (creates / updates OpenIddict applications for registered tools)
    │   └── CourseAccessValidator.cs (per-tenant access checks)
    └── wwwroot/ (static website files)

Running locally

Prerequisites:

• .NET 10 SDK. global.json pins this. The LtiAdvantage libraries multi-target net8.0 and net10.0; this sample targets net10.0.

Steps from the repo root:

dotnet build
dotnet run --project src/AdvantagePlatform.csproj

The app listens on the URL configured in Properties/launchSettings.json (default http://localhost:5099). On first run EF Core creates a SQLite advantageplatform.db in the working directory and seeds the OpenIddict swagger confidential client used by Swagger UI's "Authorize" button.

Visit:

• / — register a user and explore the test platform / course / people.
• /swagger — try the AGS / NRPS endpoints (use Swagger's Authorize, the swagger client uses the password grant).
• /.well-known/openid-configuration — OpenID Connect discovery.
• /.well-known/jwks — JSON Web Key Set used by tools to verify id_tokens.

Reference layout for a tool

Tools are configured under Tools → Create. The sample manages an OpenIddict application for each tool (client_id, redirect URI, allowed grants). The tool's PEM-encoded RSA public key is stored on the Tool entity and used to verify deep-linking responses.

LtiAdvantage provides the LTI message classes, the AGS / NRPS controller base classes (LtiAdvantage.AspNetCore.*), and the OpenIddict impersonation handler (LtiAdvantage.Oidc).

License

MIT, see LICENSE.