Glossary

Definitions of the terms used across the Arc4u documentation.

Application context

The scoped IApplicationContext service that holds the AppPrincipal of the current request or scope, or null when nobody is authenticated. AddApplicationContext registers it. See Server authentication.

AppPrincipal

The Arc4u principal, AppPrincipal: a ClaimsPrincipal that also carries the user's authorization (roles, operations and scopes) and profile. On a server, it is built from the claims of the authenticated identity. See Server authentication.

Cache context

The ICacheContext singleton that gives access to the named caches defined in configuration, by name or through its Default cache. AddCacheContext registers it. See Caching.

Claims filler

An implementation of IClaimsFiller that loads extra claims for an identity from another source, such as a backend service, while the AppPrincipal is built. The claims it returns are cached. See Server authentication.

Export attribute

The [Export] attribute of Arc4u.Dependency marks a class to register in dependency injection, optionally under a key. [Shared] makes the registration a singleton and [Scoped] a scoped service; without either, it is transient. The Arc4u source generators write the registration code. See Dependency injection.

Keyed service

A service registered in the .NET dependency injection container under a key, and resolved with that key. Arc4u uses keys to select an implementation from configuration, for example the cache Kind or the token provider ProviderId. See Design principles and Dependency injection.

Named cache

A cache defined in the Caches list of the Caching configuration section, with a Name, a Kind (the storage: Memory, Redis, RedisSentinel, Sql or Dapr) and its Settings. You get it by name from the cache context. See Caching.

ProblemDetails

The standard JSON format for errors returned by HTTP APIs, defined by RFC 9457 (application/problem+json). Arc4u converts failed results to ProblemDetails for REST endpoints, and sends them in the error details of gRPC calls. See Results and errors.

Result pattern

Returning a Result or Result<T> from FluentResults, which is either a success with a value or a failure with errors, instead of throwing exceptions for expected failures. Arc4u.Results adds extension methods and error types for it. See Results and errors.

Token provider

An implementation of ITokenProvider that obtains an access token, for example for the current user or for the application itself. Each provider is registered as a keyed service, and the ProviderId value of the security settings selects it. See Client authentication and Blazor.