llms.txt is an open proposal for a short Markdown file that lists a project's key docs and links, so AI tools can find them without crawling every page.

Where should llms.txt be deployed?

At /llms.txt on your documentation site, or in your repository root. Tools read it when they fetch it; nothing loads it automatically.

# Spring Boot 4 & Java 25 Specialist

> Java standards for Spring Boot 4 (Spring Framework 7) on Java 25. Enforces record DTOs, virtual threads, jakarta.* namespaces, HTTP service clients, and Spring Data JPA optimization.

## Quick Reference

- **Framework**: Spring Boot 4 (Spring Framework 7)

- **Language**: Java 25 LTS (Records, Virtual Threads)

- **Styling & UI**: None / API Service

- **Database / Persistence**: PostgreSQL / Spring Data JPA / Hibernate 7

- **Architectural Philosophy**: strict

## Core Architectural Invariants

- **Clean Layered Architecture**: Decouple presentation, business logic, and data access layers via interfaces.

- **Guard Clauses & Early Returns**: Exit early from functions to eliminate deeply nested if-else pyramids.

- **Schema-Driven Boundaries**: Validate all external data (API, forms, env) with Zod or Pydantic schemas; on failure, reject with a typed error and never pass unvalidated data onward.

## Operational Guardrails & Prohibited Patterns

- **Inspect Before Acting**: Always read and understand existing code and imports before suggesting changes.

- **Minimal Surgical Diffs**: Touch only lines relevant to prompt. Preserve existing comments and formatting.

- **Propose Verification Steps**: With every modification, specify concrete commands or tests to verify correctness.

## Mandatory Project Directives

- Prefer constructor dependency injection over @Autowired field injection.

- Handle business exceptions via @RestControllerAdvice with ProblemDetail (RFC 7807) responses.

## Implementation Reference

### Preferred Patterns

```ts

public record CreateOrderRequest(

@NotBlank String customerId,

@Positive BigDecimal amount

) {}

public record OrderResponse(Long id, String customerId, BigDecimal amount) {}

@RestController

@RequestMapping("/api/v1/orders")

public class OrderController {

private final OrderService orderService;

public OrderController(OrderService orderService) { this.orderService = orderService; }

@PostMapping

public ResponseEntity<OrderResponse> create(@RequestBody @Valid CreateOrderRequest request) {

return ResponseEntity.ok(orderService.processOrder(request));

}

```

### Discouraged Anti-Patterns

```ts

import javax.persistence.*; // Obsolete since Spring Boot 3; use jakarta.persistence

public class BadOrderDTO {

private String customerId;

public String getCustomerId() { return customerId; }

public void setCustomerId(String id) { this.customerId = id; }

}

```

## Verification Commands & Workflows

1. Use jakarta.* packages for persistence, validation, and servlet APIs; ban legacy javax.* imports.

2. Model request and response DTOs using native Java Records with Jakarta validation constraints.

3. Enable virtual threads (spring.threads.virtual.enabled=true) for blocking I/O throughput.

4. Configure Spring Security using SecurityFilterChain beans; never extend WebSecurityConfigurerAdapter.

5. Eliminate JPA N+1 queries using @EntityGraph or JOIN FETCH JPQL expressions.

6. Call other HTTP APIs through @HttpExchange interfaces (HTTP service clients) instead of hand-built RestTemplate code.

## Context Documents & Specs

- [System Architecture](ARCHITECTURE.md): Authoritative system design, data flows, and state machine invariants.

- [AI Multi-Agent Spec](AGENTS.md): Universal specification for autonomous coding agent operations.

Backend · Any LLM tool that fetches it

Spring Boot 4 & Java 25 llms.txt

An llms.txt for a Spring Boot 4 & Java 25 project: a short Markdown map of what it is and where the key docs and code live.

Path: llms.txt
Loads: Fetched on request
Format: Markdown index (.txt)
Used by: Any LLM tool that fetches it

All llms.txt presets and how llms.txt works

What this file tells the agent

An llms.txt gives language models and agents a short Markdown map of your Spring Boot 4 & Java 25 project: what it is and where the key docs and code live, so a tool that fetches it can go straight to the right files.

Use jakarta.* packages for persistence, validation, and servlets; ban legacy javax.* imports.
Represent immutable request/response DTOs using native Java Records with Jakarta validation annotations.
Enable virtual threads (spring.threads.virtual.enabled=true) for high-throughput blocking I/O.
Configure Spring Security using the modern SecurityFilterChain bean approach; never extend deprecated WebSecurityConfigurerAdapter.
Avoid N+1 queries in Spring Data JPA: use @EntityGraph or JOIN FETCH JPQL queries for relational fetches.

Code to avoid, and what to write instead

The rule steers the agent away from the left and toward the right.

avoid

// Discouraged: Legacy javax namespace, verbose POJO with setters, mutable entity exposure
import javax.persistence.*; // Obsolete since Spring Boot 3; use jakarta.persistence

public class BadOrderDTO {
    private String customerId;
    public void setCustomerId(String id) { this.customerId = id; }
}

write instead

package com.example.demo.order;

import jakarta.validation.constraints.NotBlank;
import jakarta.validation.constraints.Positive;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.math.BigDecimal;

public record CreateOrderRequest(
    @NotBlank String customerId,
    @Positive BigDecimal amount
) {}

public record OrderResponse(Long id, String customerId, BigDecimal amount) {}

@RestController
@RequestMapping("/api/v1/orders")
public class OrderController {
    private final OrderService orderService;

    public OrderController(OrderService orderService) {
        this.orderService = orderService;
    }

    @PostMapping
    public ResponseEntity<OrderResponse> create(@RequestBody CreateOrderRequest request) {
        OrderResponse response = orderService.processOrder(request);
        return ResponseEntity.ok(response);
    }
}

Install it in one command

01
Go to your project root
The file goes at llms.txt, relative to the root.
02
Download the file
Run the command on the right. It downloads this preset and writes the file.
03
Make sure it gets used
Nothing loads llms.txt automatically. Serve it at your site root, or point agents to it from CLAUDE.md or AGENTS.md.

$ curl -fsSL "https://www.devscratchpad.tech/api/raw/llms-txt/spring-boot-4" -o "llms.txt"

writes llms.txt

path

llms.txt

To write the file from your own code instead, use Read your code or Convert Legacy Rules in the editor above.

More for Spring Boot 4 & Java 25

Other formats

Other llms.txt presets

Questions

What is llms.txt?: llms.txt is an open proposal for a short Markdown file that lists a project's key docs and links, so AI tools can find them without crawling every page.
Where should llms.txt be deployed?: At /llms.txt on your documentation site, or in your repository root. Tools read it when they fetch it; nothing loads it automatically.

Target Standard & File Format

Identity & Activation Rules

Technology Stack Context

Engineering Philosophy

Architectural & Code Quality Conventions

Agent Behavioral Guardrails

Step-by-Step Workflow Procedures

Target File Location