Migrate to RestClient (NAV / NAIS)

Guide for replacing WebClient (reactive) and RestTemplate (legacy) with Spring's RestClient (synchronous, fluent) in NAV/NAIS applications.

When to use this skill

• Replacing WebClient with RestClient (reactive → synchronous)
• Replacing RestTemplate with RestClient (legacy → modern)
• Adding NAIS Texas token exchange (Entra ID and/or Maskinporten)
• Standardizing error handling across REST consumers
• Migrating tests from WebTestClient to RestTestClient

Decision flowchart

Before starting, assess each consumer: