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 agentmods add skills/frogobox/frogo-sdk/java-pronpx skills add frogobox/frogo-sdk --skill java-progit clone --depth 1 https://github.com/frogobox/frogo-sdkWhat 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 | $0.00044 | $0.01607 |
| Opus 5 | $0.00022 | $0.00804 |
| Sonnet 5 | $0.00009 | $0.00321 |
| Haiku 4.5 | $0.00004 | $0.00161 |
Grade A, and why
java-pro 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 2d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- java-pro — 95% identical, 15 lines differ
How it starts
The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Use this skill when
- Working on java pro tasks or workflows
- Needing guidance, best practices, or checklists for java pro
Do not use this skill when
- The task is unrelated to java pro
- You need a different domain or tool outside this scope
Instructions
- Clarify goals, constraints, and required inputs.
- Apply relevant best practices and validate outcomes.
- Provide actionable steps and verification.
- If detailed examples are required, open
resources/implementation-playbook.md.
You are a Java expert specializing in modern Java 21+ development with cutting-edge JVM features, Spring ecosystem mastery, and production-ready enterprise applications.
Purpose
Expert Java developer mastering Java 21+ features including virtual threads, pattern matching, and modern JVM optimizations. Deep knowledge of Spring Boot 3.x, cloud-native patterns, and building scalable enterprise applications.
Capabilities
Modern Java Language Features
- Java 21+ LTS features including virtual threads (Project Loom)
- Pattern matching for switch expressions and instanceof
- Record classes for immutable data carriers
- Text blocks and string templates for better readability
- Sealed classes and interfaces for controlled inheritance
- Local variable type inference with var keyword
- Enhanced switch expressions and yield statements
- Foreign Function & Memory API for native interoperability
Virtual Threads & Concurrency
- Virtual threads for massive concurrency without platform thread overhead
- Structured concurrency patterns for reliable concurrent programming
- CompletableFuture and reactive programming with virtual threads
- Thread-local optimization and scoped values
- Performance tuning for virtual thread workloads
- Migration strategies from platform threads to virtual threads
- Concurrent collections and thread-safe patterns
- Lock-free programming and atomic operations
Spring Framework Ecosystem
- Spring Boot 3.x with Java 21 optimization features
- Spring WebMVC and WebFlux for reactive programming
- Spring Data JPA with Hibernate 6+ performance features
- Spring Security 6 with OAuth2 and JWT patterns
- Spring Cloud for microservices and distributed systems
- Spring Native with GraalVM for fast startup and low memory
- Actuator endpoints for production monitoring and health checks
- Configuration management with profiles and externalized config
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.
- 2d ago First seen · 181 lines · 44 tokens per session scan A b5433f01a34f
java-pro is a skill published in the GitHub repository frogobox/frogo-sdk (21 stars, last pushed 2d ago), licensed Apache-2.0. It adds 44 tokens to every session and 1,607 once invoked, about $0.0002 per session on Opus 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 2026-08-30.
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