LTI Advantage Tool (sample)

A minimal LTI 1.3 / LTI Advantage Tool built with the LtiAdvantage library and ASP.NET Core 10. Demonstrates:

• OIDC third-party login initiation
• Resource-link launch with full id_token validation against the platform's JWKS
• Deep linking response (signed by the tool)
• Assignment and Grade Services: line items, results
• Names and Role Provisioning Service: course members
• A per-platform JWKS endpoint so the platform can validate tool-signed JWTs

Running

cd src/AdvantageTool
dotnet run

Then in a browser:

1. Open the printed URL.
2. Register a tool admin account (the password rules are deliberately lax — this is a sample).
3. Go to Platforms → Add platform and fill in your LMS's Issuer, Authorize URL, Access token URL, JWKS URL, and Client ID.
4. The page also shows the URLs to give the platform side: Login URL, Launch URL, Deep linking URL, JWKS URL, and the public key.

Where to look first

• Pages/OidcLogin.cshtml.cs — third-party login initiation.
• Pages/Tool.cshtml.cs — resource-link launch handler with full id_token validation against the platform's JWKS.
• Pages/Catalog.cshtml.cs — deep linking response: select activities, build and sign the LtiDeepLinkingResponse, post it back.
• Pages/Components/LineItems/LineItemsViewComponent.cs — token-protected AGS + NRPS calls using the LtiAdvantage models.
• Services/AccessTokenService.cs — JWT client-credentials flow.
• Services/JwksService.cs and the MapGet("/jwks/{platformId}", ...) in Program.cs — the tool's JWKS endpoint.

Platform side

A separate sample LTI Advantage platform lives at LtiAdvantagePlatform. The IMS reference implementation (lti-ri.imsglobal.org) also works.