spring-boot-dto-mapper

spring-boot-dto-mapper is a cursor rule for Cursor from lsampaioweb/ai-instructions. It costs 0 tokens per session (562 once invoked), scanned A, original, MIT.

A set of rules for mapping between API data objects and internal application models. DTOs are small data structures used at an API boundary, while a mapper converts them without mixing that work into business logic.

In plain words
What is it for?
Use it when defining request or response records, validating incoming data, or converting between API, domain, and persistence objects.
Why use it?
It keeps external request and response formats separate from internal models. This makes validation, translations, and model changes easier to control.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

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 rules/lsampaioweb/ai-instructions/spring-boot-dto-mapper
Clone the repo
git clone --depth 1 https://github.com/lsampaioweb/ai-instructions

Made for: Cursor.

Wrote 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.

agentmods badge for spring-boot-dto-mapper

README.md
[![agentmods](https://agentmods.dev/badge/rules/lsampaioweb/ai-instructions/spring-boot-dto-mapper.svg)](https://agentmods.dev/rules/lsampaioweb/ai-instructions/spring-boot-dto-mapper)
Your own site
<a href="https://agentmods.dev/rules/lsampaioweb/ai-instructions/spring-boot-dto-mapper"><img src="https://agentmods.dev/badge/rules/lsampaioweb/ai-instructions/spring-boot-dto-mapper.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 562 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 5.1 $0.00000 $0.00562
Opus 5 $0.00000 $0.00281
Sonnet 5 $0.00000 $0.00112
Haiku 4.5 $0.00000 $0.00056

Measured 5d ago against content hash 03c4817a5c6f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

spring-boot-dto-mapper 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 5d 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.

.cursor/rules/spring-boot-dto-mapper.mdc · 37 lines

How it starts

The opening of the file, as written. The whole thing — 37 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spring Boot DTO-Mapper Engine

Naming Conventions

  • Name inbound DTO types with the *Request suffix (e.g., CreateHolidayRequest, UpdateHolidayRequest).
  • Name outbound DTO types with the *Response suffix (e.g., HolidayResponse).
  • Name DTO mapper interfaces with the *DtoMapper suffix (e.g., HolidayDtoMapper).
  • Use domain-prefixed mapper names (never Mapper, DomainMapper, or EntityMapper without a domain-entity prefix).

Rules

  • For MapStruct dependency and annotation processor configuration, follow spring-boot-pom.mdc.
  • For domain/persistence model annotation bans, defer to spring-boot-model.mdc.
  • Declare request and response DTO types as Java records.
  • Declare all request and response DTO records as public.
  • Apply Bean Validation constraints (@NotBlank, @NotNull, @Email, @Positive) on all required request DTO fields.
  • Use i18n message keys as the message attribute value on all Bean Validation constraints on request DTO fields.
  • Keep mapping logic isolated in dedicated mapper types.
  • Declare a mapper interface as public only when it is shared across two or more distinct feature packages.
  • Use MapStruct for all mapper implementations when the module adopts generated mapping.
  • Set componentModel = "spring" on every @Mapper interface.
  • Set unmappedTargetPolicy = ReportingPolicy.ERROR on every @Mapper interface.
  • Use operation-specific request DTOs (CreateXRequest, UpdateXRequest) when create and update validation diverges.
  • Map all public API responses to dedicated *Response DTO types.
  • Annotate partial-update mapping methods with @BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE).
  • Annotate full-replacement mapping methods with @BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.SET_TO_NULL).
  • Define explicit collection mapping methods (e.g., List<HolidayResponse> toResponseList(List<Holiday> items)) in the mapper interface when collection mapping is needed.
  • Suppress an unmapped field only with an explicit @Mapping(target = "field", ignore = true) annotation.

Read the full file on GitHub · 37 lines

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. 5d ago First seen · 37 lines · 0 tokens per session scan A 03c4817a5c6f

Subscribe to this mod's changes

spring-boot-dto-mapper is a cursor rule published in the GitHub repository lsampaioweb/ai-instructions (1 stars, last pushed 13d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 562 tokens. 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 2026-08-31.