Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add jxoesneon/Ciel --skill java-springboot-developmentgit clone --depth 1 https://github.com/jxoesneon/CielWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/jxoesneon/ciel/java-springboot-development)<a href="https://agentmods.dev/skills/jxoesneon/ciel/java-springboot-development"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/java-springboot-development/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/jxoesneon/ciel/java-springboot-development"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/java-springboot-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00029 | $0.00509 |
| Opus 5.5 | $0.00012 | $0.00204 |
| Sonnet 5.5 | $0.00006 | $0.00102 |
| Haiku 4.5 | $0.00003 | $0.00051 |
Grade A, and why
java-springboot-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
CIEL ADAPTATION: Java & Spring Boot (The Enterprise Layer)
This skill formalizes the development of production-grade Java services using Spring Boot. It mandates immutability, fail-fast error handling, and security-first configuration.
Java Standards (17+)
- Immutability: Favor
recordandfinalfields. No setters. - Null Safety: Accept
@Nullableonly when unavoidable. UseOptionalfor return types. - Fail Fast: Use domain-specific unchecked exceptions (e.g.,
EntityNotFoundException). - Streams: Keep pipelines short and readable. Favor
List.of()and.toList().
Spring Boot Architecture
- Layered Discipline: Controller (thin) -> Service (pure logic) -> Repository (abstract access).
- Injection: Use constructor injection; prohibit
@Autowiredon fields. - Transactions: Use
@Transactional(readOnly = true)for all GETs. - Validation: Enforce
@Validon all RequestBody DTOs via Bean Validation (Zod-like patterns).
Security Review
- Auth: Default to stateless JWT. Use
OncePerRequestFilterfor validation. - CSRF: Disable for pure APIs; Enable for session-based browser apps.
- SQLi: Prohibit string concatenation in
@Query. Use:parambindings only. - PII: Never log full payloads or sensitive fields. Redact centrally.
TDD Workflow
- Unit: JUnit 5 + AssertJ + Mockito. 100% logic coverage.
- Web:
MockMvcfor controller boundary testing. - Persistence:
DataJpaTestwith Testcontainers (no H2 in CI).
Anti-Patterns
- Lombok Over-use: Using
@Dataon immutable domain entities (use@Valueorrecord). - Magic Numbers: Hardcoding timeouts or page sizes.
- Silent Catch: Catching
Exceptionwithout rethrowing or structured logging.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · -13 lines f756a2daaa68
- 1mo ago First seen · 59 lines · 29 tokens per session scan A 0f5528087219
java-springboot-development is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed 4d ago), licensed Apache-2.0. It adds 29 tokens to every session and 509 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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