Guides migration of Grails applications from Grails 7.x to Grails 8.
npx skills add https://github.com/apache/grails-core --skill grails-8-upgrade
Please help me install this Agent Skill. Skill: grails-8-upgrade Source: https://github.com/apache/grails-core/tree/main/.agents/skills/grails-8-upgrade Command: npx skills add https://github.com/apache/grails-core --skill grails-8-upgrade
Upgrading a Grails application from 7.x to Grails 8 involves breaking changes across Spring Boot 4.1, Spring Framework 7, Jackson 3, Hibernate 7, Gradle dependency management, content negotiation, and validation defaults, and missing any of them causes build failures or subtle runtime behavior changes.
@MockBean was replaced with @MockitoBean, and that content negotiation behavior was tested with real browser requests.Ask the assistant to walk through upgrading your Grails 7 application to Grails 8 and flag every breaking change in your build files, configuration, and code.
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Follow an ordered workflow: move to JDK 21+, update the Grails version and Gradle wrapper, boot with the Spring Boot properties migrator, fix dependency management and starter renames, then fix code-level Spring, Jackson, and Hibernate API changes before running tests.
No, Grails 8 supports Hibernate 5 by default. Hibernate 7 is an opt-in via the grails-hibernate7-bom enforced platform, and should only be adopted when the application is ready for Hibernate ORM 7 API removals like session.save and session.delete.
Grails 8 requires JDK 21 or later for ordinary applications. Applications using Micronaut features such as grails-micronaut or micronaut-http-client require JDK 25 or later.
Grails 8 no longer applies the io.spring.dependency-management plugin and instead uses Gradle native platform() with the Grails BOM. Replace pinned versions with direct dependencies or resolutionStrategy.force, and use enforcedPlatform for strict BOM behavior.
Grails 8 makes unconstrained persistent domain properties nullable by default, reversing the previous behavior. Add nullable: false constraints to required properties or set grails.gorm.default.nullable: false to restore the old application-wide default.
Jackson databind moves to tools.jackson.databind with JsonMapper replacing ObjectMapper, and dates default to ISO-8601 strings. Set spring.jackson.use-jackson2-defaults: true temporarily to keep Jackson 2 behavior during migration.
apacheGuide developers in building Grails 7 web applications and REST APIs.
himanshu231204Monitor deployed web applications for regressions after production deploys.
tobyileeGuide Spring Boot 3 projects through migration to Spring Boot 4 and Spring Framework 7.
netalertxDefines conventions for creating and maintaining NetAlertX settings in config.json.