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 rules/nedcodes-ok/cursorrules-collection/spring-bootgit clone --depth 1 https://github.com/nedcodes-ok/cursorrules-collectionWhat 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 | $0.00478 | $0.00478 |
| Opus 5 | $0.00239 | $0.00239 |
| Sonnet 5 | $0.00096 | $0.00096 |
| Haiku 4.5 | $0.00048 | $0.00048 |
Grade A, and why
spring-boot 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 46 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Spring Boot Cursor Rules
You are an expert Spring Boot developer. Follow these rules:
Architecture
- Layer separation: Controller → Service → Repository. No cross-layer skipping
- One @RestController per resource. Keep endpoint count under 8 per controller
- Constructor injection only. No @Autowired on fields — use final fields with @RequiredArgsConstructor
- Use @Service for business logic, @Repository for data access. Never put logic in controllers
REST Controllers
- Use @GetMapping, @PostMapping etc. — never raw @RequestMapping with method parameter
- Return ResponseEntity with explicit status codes. No void controller methods
- @Valid on all @RequestBody parameters. DTO validation via Jakarta annotations
- Pageable for list endpoints: return Page, not List
DTOs & Mapping
- Separate Request, Response, and Entity classes. Never expose entities in API responses
- Use records for DTOs in Java 17+. Immutable by default
- MapStruct for entity-DTO mapping. No manual mapping in services
- Validate with @NotNull, @Size, @Pattern — custom validators for business rules
JPA & Data
- Spring Data JPA repositories with derived query methods. @Query for complex queries
- Always use @Transactional on service methods that write. Read-only: @Transactional(readOnly = true)
- Fetch strategy: LAZY by default. Use @EntityGraph or JOIN FETCH for N+1 prevention
- Flyway or Liquibase for migrations. Never spring.jpa.hibernate.ddl-auto=update in production
Error Handling
- @RestControllerAdvice with @ExceptionHandler for global error handling
- Custom exception hierarchy: BusinessException → specific exceptions
- Return ProblemDetail (RFC 7807) for all error responses
- Log exceptions at service layer, not controller layer
Configuration
- application.yml over .properties. Profile-specific files: application-{profile}.yml
- @ConfigurationProperties for grouped config, not scattered @Value annotations
- Externalize all secrets. Use Spring Cloud Config or environment variables
- Health checks via Spring Actuator. Expose only /health and /info in production
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.
- yesterday First seen · 46 lines · 478 tokens per session scan A 4d6a849be32a
spring-boot is a cursor rule published in the GitHub repository nedcodes-ok/cursorrules-collection (37 stars, last pushed 6mo ago), licensed MIT. It adds 478 tokens to every session, about $0.0024 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.