Altinn Platform Authentication

This repository contains the Altinn Platform Authentication component. It is responsible for authenticating the users, systems and organisations that access the Altinn 3 platform, and for issuing the Altinn JSON Web Tokens (JWT) that the rest of the platform trusts.

It does two things:

• Browser sign-in — a small OIDC authorization server that delegates identity proofing to upstream providers (ID-porten, FEIDE, UIDP) and establishes an Altinn session.
• Token exchange — exchanges a trusted external token (ID-porten / Maskinporten / Altinn Studio) for an Altinn JWT.

Read more on docs.altinn.studio:

• Authentication capabilities
• Solution components
• Construction components

Build status

Documentation

In-repo documentation lives in docs/:

Doc	What
docs/architecture.md	The big picture: components, dependencies, code layout
docs/flows/	The auth flows (browser sign-in, token exchange, sessions/cookies)
docs/operations.md	Config, feature flags, secrets, health, runbook
docs/development.md	Local setup, build, run, tests
docs/adr/	Architecture Decision Records — the why
AGENTS.md	Guide for AI coding agents

Getting started

Prerequisites

1. .NET 10 SDK
2. Docker — required to run the integration tests
3. Newest Git
4. A code editor / IDE of your choice

Run locally

Clone the repo and run the component from src/Authentication:

cd src/Authentication
dotnet run

Swagger UI is then available under http://localhost:<port>/authentication/swagger.

Build & test

dotnet build Altinn.Platform.Authentication.sln
dotnet test test/Altinn.Platform.Authentication.Tests/Altinn.Platform.Authentication.Tests.csproj   # needs Docker

See docs/development.md for details — note that a passing local build does not substitute for the Docker-backed test suite.

Contributing

• Branch per change; open a pull request.
• Keep docs/ / ADRs updated in the same PR as behaviour changes.
• Known tech debt is tracked in #2074.