// the find
line/armeria
Your go-to microservice framework for any situation, from the creator of Netty et al. You can build any type of microservice leveraging your favorite technologies, including gRPC, Thrift, Kotlin, Retrofit, Reactive Streams, Spring Boot and Dropwizard.
Armeria is a mature async HTTP/2 + RPC framework built on Netty, from the team that wrote Netty itself. It unifies gRPC, Thrift, REST, and plain HTTP behind a single server/client abstraction — you can run all four on the same port. Target audience is Java backend teams building internal services at scale, especially those already invested in the reactive/Netty ecosystem.
First-class gRPC and Thrift support in the same process with shared connection pooling — no separate sidecar needed. DocService generates interactive API docs automatically from your service definitions, which is genuinely useful and something Spring doesn't give you out of the box. The decorator pattern for cross-cutting concerns (retry, circuit breaking, rate limiting, auth) is composable and consistently applied across both client and server sides. Actively maintained by LINE's engineering org with chaos tests, JMH benchmarks, and xDS/service-mesh integration already in tree.
The learning curve is steep — concepts like RequestContext propagation and the event loop threading model will bite anyone who doesn't read the docs carefully before writing production code. It's a full framework buy-in: you're not adding Armeria to an existing Spring app, you're mostly replacing your HTTP layer with it, which is a hard sell in organizations already standardized on Spring WebFlux or Quarkus. Thrift support is increasingly a legacy burden — most shops have moved to gRPC or REST, so a large slice of the API surface is irrelevant for new projects. The MCP server transport module in ai/mcp feels bolted on and early-stage compared to the rest of the codebase.