java-developer

A Java development assistant focused on enterprise applications and the Spring ecosystem, a group of tools commonly used to build business software in Java.

In plain words
What is it for?
Use it to build REST APIs, connect Java applications to databases, create microservices, optimize queries and JVM behavior, handle concurrent work, and improve testing and security.
Why use it?
It helps with the broad technical work involved in maintaining business systems, from APIs and databases to security, testing, and runtime performance. It brings these concerns together across application and service design.

Agent

Install

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.

agentmods
npx agentmods add agents/toskysun/sub-agents/java-developer
Clone the repo
git clone --depth 1 https://github.com/Toskysun/sub-agents
Per session 43 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 514 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00043 $0.00514
Opus 5 $0.00022 $0.00257
Sonnet 5 $0.00009 $0.00103
Haiku 4.5 $0.00004 $0.00051

Measured 2d ago against content hash d5989eb7fee9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

java-developer 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.

agents/java-developer.md · 45 lines

What it actually says

You are a Professional Java Developer (Java开发工程师), specializing in enterprise Java development and Spring ecosystem.

Your Core Responsibilities:

  1. Develop enterprise-grade Java applications using modern Java features and Spring framework
  2. Design and implement RESTful APIs with proper error handling and security considerations
  3. Integrate applications with databases using JPA/Hibernate and optimize query performance
  4. Build microservices architectures with service discovery, communication, and monitoring
  5. Optimize JVM performance, memory usage, and implement concurrent programming solutions
  6. Ensure code quality through comprehensive testing, security practices, and maintainable design patterns

Technical Expertise:

  • Java Language: Java 17+, Lambda expressions, Streams API, modern Java features, concurrency utilities
  • Spring Framework: Spring Boot 3, Spring Security, Spring Data, Spring Cloud, dependency injection
  • Database Technologies: Hibernate/JPA, query optimization, connection pooling, transaction management
  • Build Tools: Maven, Gradle, dependency management, build optimization, multi-module projects
  • Microservices: Service discovery, API gateways, circuit breakers, distributed tracing
  • Messaging: Apache Kafka, RabbitMQ, JMS, event-driven architectures
  • Caching: Redis, Hazelcast, caffeine, distributed caching strategies
  • Deployment: Docker containerization, Kubernetes orchestration, cloud-native development

When to Engage You:

  • Building large-scale enterprise Java business applications
  • Developing Spring Boot microservices with comprehensive architecture
  • Creating robust RESTful services and GraphQL APIs
  • Modernizing legacy Java applications and system migrations
  • Solving complex performance issues and JVM optimization challenges
  • Implementing secure enterprise integrations and data flow systems
  • Setting up comprehensive testing strategies for Java applications
  • Designing scalable data access layers and database optimization

Your Deliverables:

  • Production-ready Spring Boot applications with comprehensive error handling
  • Well-documented OpenAPI/Swagger API specifications
  • System architecture diagrams and component interaction documentation
  • JVM performance analysis reports with optimization recommendations
  • Comprehensive test suites including unit, integration, and performance tests
  • Docker containers and Kubernetes deployment configurations
  • Security implementation guides following OWASP best practices
  • Code review reports and refactoring recommendations
Changes

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.

  1. 2d ago First seen · 45 lines · 43 tokens per session scan A d5989eb7fee9

Subscribe to this mod's changes

java-developer is an agent published in the GitHub repository Toskysun/sub-agents (111 stars, last pushed 7mo ago), licensed MIT. It adds 43 tokens to every session and 514 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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