Springboot migration

Skill a-pavithraa/springboot-skills-marketplace/plugins/springboot-architecture/skills/springboot-migration

Spring Boot Skill for Claude Code and Codex

Install

npx -y skills add a-pavithraa/springboot-skills-marketplace --skill springboot-migration

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What its author says it does

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Migrates Spring Boot applications to Boot 4 with Java 25, including related Spring Modulith 2 and Testcontainers 2 upgrade work. Use when the task is a concrete upgrade, dependency transition, starter rename, test-annotation migration, or phased migration plan. Do not use for greenfield project creation or for isolated repository design questions.

SKILL.md

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Spring Boot Migration

Purpose

Use this skill for phased upgrade work on existing Spring Boot applications. This skill adds value through the migration scanner, the Boot 4 / Modulith 2 / Testcontainers 2 reference guides, and a strict migration order that avoids mixing too many changes at once.

Critical rules

Never migrate blindly. Scan the codebase first.
Never apply every migration at once. Follow phased upgrades.
Treat Java 25, Spring Boot 4, Spring Modulith 2, and Testcontainers 2 as the intended target stack for this skill unless the user asks for a narrower target.
Verify after each phase and stop when failures appear.

Workflow

Step 1: Scan the project

Use the migration scanner before planning or editing:

python3 <SKILL_DIR>/scripts/scan_migration_issues.py /path/to/project

Use the scan output to identify:

current Spring Boot version
starter rename work
annotation and import migrations
configuration changes
Spring Modulith compatibility
Testcontainers compatibility

Step 2: Identify which migrations apply

Load only the references that match the codebase:

Migration	Trigger	Read
Spring Boot 4.0	Boot 3.x to 4.x upgrade	`references/spring-boot-4-migration.md`
Spring Modulith 2.0	Existing Modulith 1.x usage	`references/spring-modulith-2-migration.md`
Testcontainers 2.x	Existing Testcontainers 1.x usage	`references/testcontainers-2-migration.md`
Cross-cutting scenarios and pitfalls	Mixed upgrade planning	`references/migration-overview.md`

Step 3: Plan the migration in phases

Use the reference guides to plan and execute in this order.

Phase 1: Dependencies

update pom.xml or build.gradle
rename starters where required
add or remove dependencies needed by the target stack
align version properties

Phase 2: Source-code changes

update imports and package names
migrate test annotations
fix Jackson 3 issues
fix Testcontainers API changes where relevant

Phase 3: Configuration

update application.properties or application.yml
apply Boot 4 defaults intentionally
update Spring Modulith event-store configuration if relevant

Phase 4: Verification

run unit tests
run integration tests
run container-based tests where present
check for deprecations and startup failures

Step 4: Use the right migration order for mixed upgrades

When multiple ecosystems are involved, use this order:

Spring Boot 4
Spring Modulith 2
Testcontainers 2

Read references/migration-overview.md before deviating from this sequence.

Step 5: Report progress after each phase

After each phase, report:

what changed
what remains
what failed, if anything
whether it is safe to continue

Reference loading guide

Spring Boot 4 migration details: references/spring-boot-4-migration.md
Spring Modulith 2 migration details: references/spring-modulith-2-migration.md
Testcontainers 2 migration details: references/testcontainers-2-migration.md
Mixed scenarios and common issues: references/migration-overview.md

Available script

scripts/scan_migration_issues.py

Output format

When planning or reporting the migration, return:

## Migration scope
- Current versions:
- Target versions:

## Planned phases
1. ...
2. ...
3. ...

## Files expected to change
- `path/to/file`

## Verification
- Tests or checks to run

When not to use this skill

Creating a new Spring Boot project from scratch
Broad architecture advice without an actual migration task
JPA-specific implementation work that belongs in spring-data-jpa