Agent Skills

This is a Spring AI Community project (spring-ai-community/spring-testing-skills) and is not part of the AgentWorks platform. It uses its own repository and Maven coordinates (org.springaicommunity).

Skills are curated knowledge packages that teach agents how to do specific things well. Each skill is a structured Markdown file with routing rules and reference patterns. Agents discover skills at startup and load full content only when relevant — no tokens wasted on unused knowledge. Skills follow the SkillsJars specification and work in any agentic CLI — Loopy, Claude Code, and 40+ others.

Spring Testing Skills

The first production-ready SkillsJars collection — 7 skills that teach agents how to test Spring applications.

Skill	Domain
spring-testing-router	Meta-skill — routes to the right domain skill based on the task
spring-jpa-testing	`@DataJpaTest`, Testcontainers, `@ServiceConnection`, Hibernate 6/7, lazy loading
spring-mvc-testing	`@WebMvcTest`, `MockMvc`, `jsonPath`, request validation, `@RestControllerAdvice`
spring-security-testing	`@WithMockUser`, CSRF, JWT, OAuth2, `@PreAuthorize` method security
spring-webflux-testing	`@WebFluxTest`, `WebTestClient`, `StepVerifier`, virtual time, SSE
spring-websocket-testing	STOMP/WebSocket, `WebSocketStompClient`, `BlockingQueue` pattern
spring-testing-fundamentals	AssertJ, BDDMockito, `ArgumentCaptor`, context caching, anti-patterns

Skill Structure

Each skill has a SKILL.md with metadata and routing rules, plus a references/ directory with detailed patterns:

skills/spring-jpa-testing/
├── SKILL.md                       # Metadata + routing rules
└── references/
    ├── testcontainers.md          # Detailed patterns
    ├── transactional-tests.md
    ├── lazy-loading-tests.md
    └── hibernate-6-migration.md

Install

git clone https://github.com/spring-ai-community/spring-testing-skills.git
cd spring-testing-skills
./mvnw package
mvn skillsjars:extract -Ddir=~/.claude/skills

Skills are extracted to ~/.claude/skills/ where any agentic CLI discovers them automatically.

Evidence

In the Code Coverage v2 experiment, adding testing skills:

Reduced JAR_INSPECT tool calls from 11.0% → 1.0% — the agent stopped inspecting dependencies because the skills already provided the knowledge
Reduced expected steps by ~25% compared to baseline

Updated 2026-08-27 — the absolute figures are withdrawn. This read “25% (224 vs 301).” The 224 reproduces exactly from a chain that grouped by item rather than by run: v2 ran 2–3 runs against a single item, so every run of a variant was concatenated into one sequence, losing all but one absorption event and inflating expected steps about threefold (defect CT6). Recomputed with trajectories separated: 74.7 vs ~101–109, depending on which baseline arm is meant — the page does not say, which is its own defect.The ~25% survives because both arms were inflated by the same factor. The absolute numbers do not. See the v2 experiment page and agent-control-theory d18fc50.

This validates the thesis: curated knowledge improves agent quality more than model upgrades.

Creating Custom Skills

Any Markdown file with YAML frontmatter can be a skill:

---
name: my-team-conventions
description: Coding conventions for our Spring Boot services
---

# Instructions

When working on this codebase:
- Use constructor injection, never field injection
- All REST endpoints return ProblemDetail for errors (RFC 9457)
- Tests use @WebMvcTest with MockMvc, not @SpringBootTest

Place in .claude/skills/my-conventions/SKILL.md (project) or ~/.claude/skills/my-conventions/SKILL.md (global).

Projects

AgentWorks

Supporting Projects

Migration

Spring Testing Skills

Skill Structure

Install

Evidence

Creating Custom Skills

Documentation

Spring Testing Skills

SkillsJars Spec

​Spring Testing Skills

​Skill Structure

​Install

​Evidence

​Creating Custom Skills

​Documentation

Spring Testing Skills

SkillsJars Spec

Spring Testing Skills

Skill Structure

Install

Evidence

Creating Custom Skills

Documentation