Micronaut Framework 5.2.0 Released!

The Micronaut Foundation is excited to announce the release of Micronaut Framework 5.2.0!

It includes releases of Micronaut Core 5.2.8, Micronaut Jakarta EL 1.1.0, Micronaut LangChain4j 2.3.0, Micronaut MCP 2.1.0, Micronaut Data 5.2.0, Micronaut SQL 7.2.0, Micronaut MongoDB 6.2.0, Micronaut R2DBC 7.2.0, Micronaut GCP 6.2.0, Micronaut Security 5.4.0, Micronaut Reactor 4.3.0, Micronaut Views 6.3.1, Micronaut Test 5.2.0, Micronaut Test Resources 4.3.0, Micronaut Validation 5.2.0, Micronaut JSON Schema 2.2.0, Micronaut OpenAPI 7.2.0, Micronaut Serialization 3.2.2, Micronaut Servlet 6.2.1, and Micronaut SourceGen 2.2.3.

What’s new in Micronaut Framework 5.2.0

Micronaut Core

Micronaut Core 5.2.8 adds experimental Micronaut for Python support with GraalPy, the HTTP QUERY method, Cross-Origin-Embedder-Policy and Cross-Origin-Resource-Policy header configuration, extensible response header populators, and switches to activate or deactivate Netty globally or per server and client.

It also adds a configurable HTTP/2 connection receive window, control over singleton destruction order, @Bean(preDestroy) on bean classes, a micronaut-reflection module, configuration metadata derived from Kotlin KDoc, and language-neutral extension points for Scala. The release reduces cold-start and annotation-processing work, fixes several HTTP and KSP2 issues, and updates Jackson to 3.2.2, Kotlin to 2.4.10, and GraalVM to 25.4.4.1.1.

New module: Micronaut Jakarta EL

Micronaut Jakarta EL 1.1.0 is a complete implementation of Jakarta Expression Language 6.0. Expressions are compiled at build time by an annotation processor, with an optional sandboxed runtime interpreter. Its public API is @Experimental.

AI

Micronaut LangChain4j 2.3.0 updates LangChain4j to 1.20.0 and makes retrieval-augmented generation opt-in through an explicit RetrievalAugmentor or ContentRetriever bean. Micronaut MCP 2.1.0 updates the MCP Java SDK to 2.0.1.

Data access

Micronaut Data 5.2.0 adds upserts, Oracle transaction recovery, sessionless transactions, lock-free reservations, native BOOLEAN columns, geography mapping, and criteria navigation through associations. Micronaut SQL 7.2.0 updates its database dependencies and simplifies GraalVM native-image metadata for jOOQ.

Micronaut MongoDB 6.2.0 updates the MongoDB Java Driver to 5.12.0. Micronaut R2DBC 7.2.0 updates the MySQL, MariaDB, PostgreSQL, and Microsoft SQL Server R2DBC drivers.

Cloud, security, and reactive programming

Micronaut GCP 6.2.0 fixes request body framing and multipart form field binding in HTTP functions and updates Google Cloud dependencies. Micronaut Security 5.4.0 adds Reporting API endpoint support and an authentication bypass for anonymous static resources.

Micronaut Reactor 4.3.0 updates its dependency and Micronaut alignment. Micronaut Views 6.3.1 adds React server-bundle browser refresh support, pluggable rendering contexts, and an option to omit the hydration bootstrap.

Test, validation, and APIs

Micronaut Test 5.2.0 adds support for JUnit parallel test execution and updates Kotest to 6.2.5. Micronaut Test Resources 4.3.0 adds an Azure Cosmos emulator test resource and a thin test resources server artifact.

Micronaut Validation 5.2.0 updates its dependencies and Micronaut alignment. Micronaut JSON Schema 2.2.0 adds record generation from discovered schemas and keeps JSON validation reports reachable in native images.

Micronaut OpenAPI 7.2.0 expands $dynamicRef generation to all generic shapes and upgrades OpenAPI Generator to 7.25.0 and Swagger to 2.2.55. Micronaut Serialization 3.2.2 adds CBOR, YAML, XML, and experimental Protocol Buffers support, configurable deserialization coercions, strict builders, and Jackson object identity annotations.

Micronaut Servlet 6.2.1 adds WebSocket support for Jetty, Tomcat, and Undertow, including Jakarta WebSocket annotations, and brings the servlet servers closer to parity with the Netty server.

Build and platform updates

Micronaut SourceGen 2.2.3 adds a JDK ClassFile bytecode backend, staged builders, @Wither on individual record components, method references, and full record support in the bytecode writer.

The Micronaut Platform 5.2.0 guide adds a Platform 5 Migration Impact appendix. The platform also updates JUnit to 6.1.3, Lombok to 1.18.48, SpotBugs to 4.10.4, and the managed Maven build plugins.

If you haven’t yet updated to Micronaut Framework 5, this is an excellent opportunity to do so!

Please feel free to reach out to us if you need any assistance.