Ratpack Migration Analysis

CodeLens deliberately ships no Ratpack-specific features. Instead it exposes a small set of framework-agnostic primitives that return exhaustive bytecode facts. This skill is the worked example of turning those facts into a Ratpack migration assessment: you supply the Ratpack knowledge (which FQNs are handlers, what the Promise API looks like — see the reference docs), CodeLens supplies the data, and you supply the judgment (complexity, ordering, severity). Nothing here is a tool verdict; you read raw facts and explain your reasoning.

When to use

• Scope or plan a migration off Ratpack (to Spring MVC/WebFlux, Micronaut, etc.).
• Inventory handlers, routes, Promise/async usage, Guice DI, external integrations.
• Find constructs that complicate a migration (blocking on the compute thread, etc.).
• Propose a migration order grounded in the dependency graph.

Prerequisites