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.
git clone --depth 1 https://github.com/GoranErhartic/cursor-development-rulesWrote 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/rules/goranerhartic/cursor-development-rules/jpa)<a href="https://agentmods.dev/rules/goranerhartic/cursor-development-rules/jpa"><img src="https://agentmods.dev/badge/rules/goranerhartic/cursor-development-rules/jpa/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/rules/goranerhartic/cursor-development-rules/jpa"><img src="https://agentmods.dev/badge/rules/goranerhartic/cursor-development-rules/jpa.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 | $0.00014 | $0.00282 |
| Opus 5.5 | $0.00006 | $0.00113 |
| Sonnet 5.5 | $0.00003 | $0.00056 |
| Haiku 4.5 | $0.00001 | $0.00028 |
Grade A, and why
jpa 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
Spring Data JPA
Entities
- @Entity, @Table; @Id, @GeneratedValue; @Column; @OneToMany, @ManyToOne with FetchType; avoid N+1 (use JOIN FETCH or entity graph).
- Use records or DTOs for read-only projections (interface or class) to limit loaded data.
Repositories
- Extend JpaRepository; derived queries (findByX); @Query for JPQL or native (use native with care, parameterized); @Modifying for update/delete with @Transactional.
- Use Pageable for pagination; return Page or Slice.
Transactions
- @Transactional on service methods; readOnly = true for read-only; propagation for nested; rollback on runtime exceptions by default.
- Keep transactions short; do not hold across HTTP or long operations.
Conventions
- Single aggregate per transaction when possible; avoid N+1; use projections for lists; version for optimistic locking; do not expose entities directly in API (map to DTOs).
Anti-Patterns
- N+1 queries; long transactions; exposing entities in API; raw SQL with concatenation; missing @Transactional on write
See also: validation.mdc, error-handling.mdc, ../../patterns/architecture.mdc
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 First seen · 31 lines · 14 tokens per session scan A 6546a6e07f4a
jpa is a cursor rule published in the GitHub repository GoranErhartic/cursor-development-rules (19 stars, last pushed 7mo ago), licensed MIT. It adds 14 tokens to every session and 282 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 2026-08-30.
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