# AGENTS.md — 开发规范 / Development Guidelines

> 本文件为所有 AI 编码助手（Claude Code、pi、Cursor 等）提供统一的开发指导。
> This file provides unified development guidelines for all AI coding assistants.

**最后更新 / Last Updated**: 2026-06-10

---

## 目录 / Table of Contents

1. [语言 / Language](#1-语言--language)
2. [代码风格 / Code Style](#2-代码风格--code-style)
3. [禁止模式 / Forbidden Patterns](#3-禁止模式--forbidden-patterns)
4. [错误处理 / Error Handling](#4-错误处理--error-handling)
5. [安全规范 / Security](#5-安全规范--security)
6. [数据库规范 / Database](#6-数据库规范--database)
7. [API 设计规范 / API Design](#7-api-设计规范--api-design)
8. [日志与可观测性 / Logging & Observability](#8-日志与可观测性--logging--observability)
9. [性能规范 / Performance](#9-性能规范--performance)
10. [测试规范 / Testing](#10-测试规范--testing)
11. [Git 规范 / Git Workflow](#11-git-规范--git-workflow)
12. [工作流程 / Workflow](#12-工作流程--workflow)
13. [架构决策记录 / ADR](#13-架构决策记录--adr)
14. [审查清单 / Review Checklist](#14-审查清单--review-checklist)

---

## 1. 语言 / Language

**Always respond in Chinese (中文).** Use the user's language for all conversations and explanations. Code, commands, and technical terms can remain in English.

始终使用中文回复。代码、命令和技术术语可以保留英文。

---

## 2. 代码风格 / Code Style

### 2.1 基本原则 / Basic Principles

| 规则 / Rule | 说明 / Description                                                                        |
|-----------|-----------------------------------------------------------------------------------------|
| 遵循现有风格    | Follow existing project conventions                                                     |
| 有意义命名     | Use meaningful variable names; avoid single-letter names except loop counters           |
| 函数长度      | Keep functions under **50 lines**; split complex logic into smaller functions           |
| 嵌套深度      | Maximum nesting depth: **3 levels**; use early returns to flatten logic                 |
| 圈复杂度      | Function cyclomatic complexity should not exceed **10**                                 |
| 注释        | Add comments for complex logic only; prefer self-documenting code                       |
| 文档注释      | Public items must have `///` doc comments; private items only when logic is non-obvious |

### 2.2 Rust 最佳实践 / Rust Best Practices

```rust
// ✅ 正确 / Correct
fn get_user(id: i64) -> AppResult<User> {
    let user = db.find_user(id).await?;  // 使用 ? 传播错误
    Ok(user)
}

// ❌ 错误 / Incorrect
fn get_user(id: i64) -> User {
    db.find_user(id).await.unwrap()  // 禁止 unwrap()
}
```

| 规则 / Rule | 说明 / Description                                                                            |
|-----------|---------------------------------------------------------------------------------------------|
| 错误传播      | Use `?` operator for error propagation; never use `unwrap()` or `expect()` in non-test code |
| `unsafe`  | Avoid `unsafe` blocks; if necessary, add a `// SAFETY:` comment explaining why              |
| `clone()` | Minimize `clone()` usage; prefer references or `Rc`/`Arc` for shared ownership              |
| 魔法数字      | No magic numbers; define named constants with `const`                                       |
| 硬编码字符串    | No hardcoded strings for config/status; use enums or constants                              |
| 死代码       | Remove dead code; don't leave commented-out code blocks                                     |
| 未完成代码     | Don't commit `unimplemented!()`, `todo!()`, or `FIXME` without a tracking issue             |

### 2.3 导入规范 / Import Guidelines

```rust
// 标准库 → 第三方 crate → 本地模块
// stdlib → third-party crates → local modules
use std::collections::HashMap;

use serde::{Deserialize, Serialize};
use sqlx::FromRow;

use crate::error::{AppError, AppResult};
use crate::models::common::Status;
```

---

## 3. 禁止模式 / Forbidden Patterns

以下代码模式在项目中严格禁止：

The following code patterns are strictly forbidden in this project:

| 禁止项 / Forbidden               | 说明 / Reason                                    |
|-------------------------------|------------------------------------------------|
| `// ── xxxx ──────────`       | 禁止使用此类分隔线注释；使用 `// Section: xxx` 格式替代          |
| `unwrap()` / `expect()` (非测试) | 在非测试代码中禁止使用；使用 `?` 或 `unwrap_or` 等安全替代         |
| `panic!()` / `unreachable!()` | 除极少数不可能到达的分支外禁止使用；使用 `AppError` 替代             |
| 未处理的 `todo!()`                | 不得提交包含 `todo!()` 的代码，除非有对应的 issue 追踪           |
| 注释掉的代码                        | 不得提交被注释的代码块；使用 Git 历史追溯                        |
| 过深嵌套 (≥4层)                    | 使用 early return、`match`、`map`/`and_then` 扁平化逻辑 |
| 过长函数 (>50行)                   | 拆分为更小的、职责单一的函数                                 |
| 魔法数字                          | 使用 `const` 定义命名常量                              |
| 硬编码字符串                        | 使用枚举或常量定义配置值/状态值                               |
| 死代码                           | 删除未使用的代码、导入和变量                                 |

---

## 4. 错误处理 / Error Handling

### 4.1 错误类型体系 / Error Type System

```rust
// 统一使用 AppError 和 AppResult
// Use AppError and AppResult consistently
use crate::error::{AppError, AppResult};

pub async fn create_user(req: CreateUserReq) -> AppResult<User> {
    // ...
}
```

- **AppError**: 统一错误枚举，包含领域错误和外部库包装
- **AppResult<T>**: `Result<T, AppError>` 的类型别名

### 4.2 错误处理原则 / Error Handling Principles

| 原则 / Principle | 说明 / Description                                                                |
|----------------|---------------------------------------------------------------------------------|
| 显式处理           | Handle all errors explicitly; no silent failures                                |
| 用户友好           | Internal errors are logged and masked; user-facing messages should be helpful   |
| 错误上下文          | Use `.context()` or `.map_err()` to add meaningful context to errors            |
| 错误分类           | Domain errors (UserNotFound) vs Infrastructure errors (DatabaseError)           |
| Postgres 映射    | Map Postgres error codes (23505 unique, 23503 FK, 23514 check) to HTTP statuses |

### 4.3 错误日志格式 / Error Logging Format

```rust
// 记录错误时包含完整上下文
// Log errors with full context
tracing::error!(
    error = %err,
    user_id = %user_id,
    operation = "create_user",
    "Failed to create user"
);
```

### 4.4 错误恢复策略 / Error Recovery

| 场景 / Scenario | 策略 / Strategy |
|---------------|---------------|
| 数据库连接失败       | 重试 + 降级到只读模式  |
| 外部服务超时        | 断路器 + 降级响应    |
| 缓存 miss       | 回退到数据库查询      |
| 队列积压          | 背压控制 + 告警     |

---

## 5. 安全规范 / Security

### 5.1 基础安全 / Basic Security

| 规则 / Rule | 说明 / Description                                              |
|-----------|---------------------------------------------------------------|
| 密钥管理      | Never hardcode secrets or API keys; use environment variables |
| 输入验证      | Always validate and sanitize user input                       |
| SQL 注入    | Use parameterized queries (sqlx handles this automatically)   |
| XSS 防护    | Escape output; use Content-Security-Policy headers            |
| CSRF 防护   | Use CSRF tokens for state-changing operations                 |
| 密码安全      | Argon2 hashing with session-scoped RSA-2048 OAEP-SHA256       |
| 2FA       | TOTP with HMAC-SHA1, base32 secrets, backup codes             |

### 5.2 OWASP Top 10 防护 / OWASP Top 10 Protection

| 风险 / Risk | 防护措施 / Mitigation                                    |
|-----------|------------------------------------------------------|
| 注入        | Parameterized queries, input validation              |
| 失效认证      | Strong password policy, 2FA, session management      |
| 敏感数据暴露    | Encryption at rest and in transit, data masking      |
| XML 外部实体  | Disable XML external entity processing               |
| 失效访问控制    | Role-based access control, resource ownership checks |
| 安全配置错误    | Secure defaults, environment-based config            |
| XSS       | Output encoding, CSP headers                         |
| 不安全反序列化   | Validate serialized data, use safe formats           |
| 使用含漏洞组件   | Regular dependency updates, `cargo audit`            |
| 日志和监控不足   | Comprehensive logging, alerting                      |

### 5.3 企业级安全 / Enterprise Security

| 要求 / Requirement | 说明 / Description                                                     |
|------------------|----------------------------------------------------------------------|
| 安全审计日志           | Log all sensitive operations with actor, action, resource, timestamp |
| 访问控制             | Implement RBAC/ABAC; check permissions at service layer              |
| 数据脱敏             | Mask PII in logs; encrypt sensitive fields in database               |
| 依赖安全             | Run `cargo audit` in CI; review new dependencies                     |
| 安全头              | Set HSTS, X-Frame-Options, X-Content-Type-Options, etc.              |
| 速率限制             | Implement rate limiting for auth endpoints and API calls             |

---

## 6. 数据库规范 / Database

### 6.1 基础规范 / Basic Rules

| 规则 / Rule | 说明 / Description                                                     |
|-----------|----------------------------------------------------------------------|
| 参数化查询     | Always use parameterized queries (sqlx does this by default)         |
| 事务管理      | Use `ServiceContext::run_in_transaction()` for multi-step operations |
| 读写分离      | Use `AppDatabase` read/write pool methods appropriately              |
| 迁移规范      | All schema changes must go through migration files in `migrate/`     |

### 6.2 性能优化 / Performance Optimization

| 规则 / Rule | 说明 / Description                                                     |
|-----------|----------------------------------------------------------------------|
| N+1 防护    | Use `JOIN` or batch queries instead of N+1 patterns                  |
| 批量操作      | Use `INSERT ... ON CONFLICT`, `UPDATE ... FROM`, bulk operations     |
| 索引规范      | Add indexes for frequently queried columns; document index rationale |
| 查询分析      | Use `EXPLAIN ANALYZE` to verify query plans for complex queries      |
| 连接池       | Configure pool sizes based on workload; monitor connection usage     |
| 慢查询       | Log queries >100ms; investigate and optimize                         |

### 6.3 数据一致性 / Data Consistency

| 规则 / Rule | 说明 / Description                                          |
|-----------|-----------------------------------------------------------|
| 事务边界      | Keep transactions short; avoid long-running transactions  |
| 幂等性       | Design operations to be idempotent where possible         |
| 乐观锁       | Use version columns for concurrent update protection      |
| 外键约束      | Use database-level foreign keys for referential integrity |

---

## 7. API 设计规范 / API Design

### 7.1 RESTful 规范 / RESTful Conventions

| 规则 / Rule | 示例 / Example                                                                            |
|-----------|-----------------------------------------------------------------------------------------|
| 资源命名      | `/api/v1/workspaces/{id}/repos` (复数名词)                                                  |
| HTTP 方法   | GET (读取), POST (创建), PUT/PATCH (更新), DELETE (删除)                                        |
| 状态码       | 200 (成功), 201 (创建), 204 (无内容), 400 (客户端错误), 401 (未认证), 403 (禁止), 404 (未找到), 500 (服务器错误) |
| 版本管理      | URL path versioning: `/api/v1/...`                                                      |

### 7.2 响应格式 / Response Format

```rust
// 统一响应类型
// Unified response types
ApiResponse<T>          // 单个数据 / Single payload
ApiListResponse<T>      // 分页列表 / Paginated list { data, total, page, per_page }
ApiEmptyResponse        // 空响应 / Empty response
ApiErrorResponse        // 错误响应 / Error response { code, message, details }
```

### 7.3 OpenAPI 文档 / OpenAPI Documentation

```rust
// 每个端点必须添加 OpenAPI 注解
// Every endpoint must have OpenAPI annotations
#[utoipa::path(
    post,
    path = "/api/v1/auth/login",
    request_body = LoginReq,
    responses(
        (status = 200, description = "Login successful", body = ApiResponse<LoginResp>),
        (status = 401, description = "Invalid credentials", body = ApiErrorResponse)
    ),
    tag = "auth"
)]
pub async fn login(...) -> HttpResponse { ... }
```

### 7.4 API 治理 / API Governance

| 规则 / Rule | 说明 / Description |
|---|---|
| 请求验证 | Validate all request bodies and query parameters |
| 速率限制 | Apply rate limiting to auth and resource-intensive endpoints |
| 幂等性 | POST operations with same idempotency key should produce same result |
| 缓存策略 | Use ETag/Last-Modified for cacheable resources |
| 错误码体系 | Consistent error codes across all endpoints |
| 分页 | Default page size 20, max 100; use cursor-based pagination for large datasets |

---

## 8. 日志与可观测性 / Logging & Observability

### 8.1 日志规范 / Logging Standards

```rust
// 使用 tracing crate 进行结构化日志
// Use tracing crate for structured logging
use tracing::{info, warn, error, debug, instrument};

#[instrument(skip(db), fields(user_id = %req.user_id))]
pub async fn create_user(req: CreateUserReq) -> AppResult<User> {
    info!("Creating new user");
    // ...
    error!(error = %err, "Failed to create user");
}
```

| 级别 / Level | 用途 / Usage |
|---|---|
| `error` | 错误需要立即关注 / Errors requiring immediate attention |
| `warn` | 异常但可恢复的情况 / Abnormal but recoverable situations |
| `info` | 关键业务操作记录 / Key business operation records |
| `debug` | 开发调试信息 / Development debugging info |
| `trace` | 详细执行路径 / Detailed execution paths |

### 8.2 敏感信息脱敏 / Data Masking

| 数据类型 / Data Type | 脱敏规则 / Masking Rule |
|---|---|
| 密码 | 完全隐藏 / Never log |
| Token/密钥 | 只显示前 4 位 / Show first 4 chars only |
| 邮箱 | `u***@example.com` |
| IP 地址 | 保留网段 / Keep subnet |
| 个人信息 | 根据最小必要原则 / Minimum necessary principle |

### 8.3 性能指标 / Metrics

| 指标 / Metric | 说明 / Description |
|---|---|
| 请求延迟 | HTTP request latency (P50, P95, P99) |
| 错误率 | Error rate by endpoint and status code |
| 吞吐量 | Requests per second |
| 数据库连接 | Active/idle connections in pool |
| 缓存命中率 | Cache hit/miss ratio |
| 队列积压 | Queue depth and processing rate |
| 内存使用 | Heap usage, allocation rate |
| 活跃会话 | Active WebSocket sessions |

### 8.4 健康检查 / Health Checks

```rust
// 端点: GET /health
// Endpoint: GET /health
{
    "status": "healthy",           // healthy | degraded | unhealthy
    "version": "1.0.0",
    "uptime": 3600,
    "checks": {
        "database": { "status": "up", "latency_ms": 5 },
        "redis": { "status": "up", "latency_ms": 2 },
        "nats": { "status": "up", "latency_ms": 1 },
        "etcd": { "status": "up", "latency_ms": 3 }
    }
}
```

### 8.5 告警规则 / Alerting Rules

| 条件 / Condition | 级别 / Level |
|---|---|
| 错误率 > 5% | Critical |
| P99 延迟 > 500ms | Warning |
| 数据库连接池 > 80% | Warning |
| 队列积压 > 1000 | Critical |
| 内存使用 > 85% | Warning |
| 健康检查失败 | Critical |

### 8.6 请求链路追踪 / Request Tracing

```rust
// 每个请求分配唯一 trace_id
// Each request gets a unique trace_id
tracing::info!(
    trace_id = %request_id,
    user_id = %session.user_id,
    method = %req.method(),
    path = %req.path(),
    "Request started"
);
```

---

## 9. 性能规范 / Performance

### 9.1 SLA 目标 / SLA Targets

| 指标 / Metric | 目标 / Target |
|---|---|
| 可用性 | 99.9% (每月宕机 <43 分钟) |
| P50 延迟 | <50ms |
| P95 延迟 | <200ms |
| P99 延迟 | <500ms |
| 错误率 | <0.1% |
| 数据库查询 | <100ms (常规查询) |
| 缓存命中率 | >90% |

### 9.2 性能原则 / Performance Principles

| 原则 / Principle | 说明 / Description |
|---|---|
| 基准测试 | Establish performance baselines before optimization |
| 测量优先 | Profile before optimizing; don't guess |
| 渐进优化 | Optimize iteratively; measure impact of each change |
| 容量规划 | Plan for 3x current load |

### 9.3 优化策略 / Optimization Strategies

| 场景 / Scenario | 策略 / Strategy |
|---|---|
| 热点查询 | Add caching (L1 + L2) |
| 大量读取 | Use read replicas |
| 批量操作 | Batch database operations |
| 高并发 | Use connection pooling, async I/O |
| 大数据量 | Use cursor-based pagination |

---

## 10. 测试规范 / Testing

### 10.1 基础要求 / Basic Requirements

| 规则 / Rule | 说明 / Description |
|---|---|
| 新功能 | All new features must have unit tests |
| Bug 修复 | Bug fixes must include regression tests |
| 关键路径 | Critical business logic must have integration tests |
| 测试隔离 | Tests must be independent and not depend on execution order |

### 10.2 测试命令 / Test Commands

```bash
cargo test                       # 运行所有测试 / Run all tests
cargo test -- <test_name>        # 按名称运行 / Run by name
cargo test lru::tests            # 运行特定模块 / Run module tests
cargo test -- --nocapture        # 显示输出 / Show output
```

### 10.3 测试命名 / Test Naming

```rust
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_create_user_with_valid_input() { ... }

    #[test]
    fn test_create_user_with_duplicate_email_returns_error() { ... }

    #[tokio::test]
    async fn test_async_operation_handles_timeout() { ... }
}
```

---

## 11. Git 规范 / Git Workflow

### 11.1 提交信息格式 / Commit Message Format

使用 Angular 风格，全部英文：

Use Angular style, all English:

```
<type>(<scope>): <subject>

[optional body]

[optional footer]
```

| Type | 说明 / Description |
|---|---|
| `feat` | 新功能 / New feature |
| `fix` | Bug 修复 / Bug fix |
| `refactor` | 重构 / Code refactoring |
| `docs` | 文档 / Documentation |
| `test` | 测试 / Tests |
| `chore` | 构建/工具 / Build/tooling |
| `perf` | 性能优化 / Performance improvement |
| `style` | 代码格式 / Code formatting |
| `ci` | CI/CD 相关 / CI/CD changes |

**示例 / Examples:**
```
feat(auth): add 2FA login support
fix(api): resolve race condition in user creation
refactor(service): extract common validation logic
docs(readme): update API documentation
test(cache): add unit tests for LRU eviction
chore(deps): update sqlx to 0.8
```

### 11.2 提交原则 / Commit Principles

| 原则 / Principle | 说明 / Description |
|---|---|
| 原子提交 | Each commit should address one concern |
| 完整性 | Each commit should leave the codebase in a working state |
| 禁止强制推送 | Never force push to main branch |
| 提交前检查 | Run `cargo check` and `cargo test` before committing |

### 11.3 分支策略 / Branch Strategy

| 分支 / Branch | 用途 / Purpose |
|---|---|
| `main` | 生产就绪代码 / Production-ready code |
| `feat/*` | 功能开发 / Feature development |
| `fix/*` | Bug 修复 / Bug fixes |
| `release/*` | 发布准备 / Release preparation |

---

## 12. 工作流程 / Workflow

### 12.1 开发流程 / Development Process

1. **理解先于编写** — Read before write; understand context first
2. **最小变更** — Minimal changes; don't refactor unrelated code
3. **验证变更** — Verify after changes; run tests or check output
4. **文档同步** — Update documentation when changing public APIs

### 12.2 AI 助手工作规范 / AI Assistant Guidelines

| 规则 / Rule | 说明 / Description |
|---|---|
| 先读后写 | Always read existing code before making changes |
| 最小侵入 | Make minimal changes; don't refactor unrelated code |
| 验证结果 | Run `cargo check` or `cargo test` after changes |
| 解释变更 | Explain what you changed and why |
| 询问不确定 | Ask when unsure about requirements |

### 12.3 常用命令 / Common Commands

```bash
cargo build                      # 构建 / Build
cargo check                      # 快速检查 / Quick check
cargo test                       # 运行测试 / Run tests
cargo clippy                     # Lint 检查 / Lint checks
cargo fmt                        # 格式化 / Format code
cargo doc --no-deps              # 生成文档 / Build docs
cargo machete                    # 检查未使用依赖 / Check unused deps
cargo run --bin gen_openapi      # 生成 OpenAPI / Generate OpenAPI
```

---

## 13. 架构决策记录 / ADR

架构决策记录存放在 `docs/adr/` 目录下，使用 Markdown 格式。

Architecture Decision Records are stored in `docs/adr/` directory in Markdown format.

### 索引 / Index

| ADR | 标题 / Title | 状态 / Status |
|---|---|---|
| [ADR-001](docs/adr/001-choice-of-web-framework.md) | 选择 Actix-web 作为 Web 框架 | Accepted |
| [ADR-002](docs/adr/002-two-tier-caching.md) | 两级缓存架构 (L1 LRU + L2 Redis) | Accepted |
| [ADR-003](docs/adr/003-nats-for-messaging.md) | 使用 NATS JetStream 作为消息队列 | Accepted |
| [ADR-004](docs/adr/004-etcd-for-discovery.md) | 使用 etcd 进行服务发现 | Accepted |
| [ADR-005](docs/adr/005-error-handling-strategy.md) | 统一错误处理策略 | Accepted |

### ADR 模板 / ADR Template

```markdown
# ADR-NNN: 标题 / Title

## 状态 / Status
Accepted | Superseded | Deprecated

## 背景 / Context
描述问题背景 / Describe the context

## 决策 / Decision
描述做出的决策 / Describe the decision

## 后果 / Consequences
描述正面和负面影响 / Describe positive and negative impacts
```

---

## 14. 审查清单 / Review Checklist

### 代码审查 / Code Review

- [ ] 代码风格符合项目规范 / Code style follows project conventions
- [ ] 没有使用禁止模式 / No forbidden patterns used
- [ ] 错误处理完整 / Error handling is complete
- [ ] 安全考虑已处理 / Security considerations addressed
- [ ] 性能影响已评估 / Performance impact assessed
- [ ] 测试已添加 / Tests are added
- [ ] 文档已更新 / Documentation is updated

### PR 审查 / PR Review

- [ ] 提交信息符合 Angular 风格 / Commit messages follow Angular style
- [ ] 每个提交只关注一个问题 / Each commit addresses one concern
- [ ] 变更范围合理 / Change scope is reasonable
- [ ] 没有遗留的 TODO/FIXME / No leftover TODO/FIXME
- [ ] CI 检查通过 / CI checks pass

### 发布前审查 / Pre-release Review

- [ ] 所有测试通过 / All tests pass
- [ ] 性能测试完成 / Performance tests completed
- [ ] 安全扫描通过 / Security scan passed
- [ ] 文档完整 / Documentation is complete
- [ ] 变更日志已更新 / Changelog is updated

---

## 附录 / Appendix

### 项目架构速查 / Quick Architecture Reference

```
appks — 协作开发平台后端 / Collaborative Development Platform Backend

config/          → 环境配置 / Environment configuration
models/          → 数据模型 / Data models (sqlx FromRow)
service/         → 业务逻辑 / Business logic (AppService)
api/             → HTTP 端点 / HTTP endpoints
immediate/       → 实时 IM / Real-time IM (WebSocket)
cache/           → 两级缓存 / Two-tier cache (L1 + L2)
storage/         → 对象存储 / Object storage (S3)
queue/           → 消息队列 / Message queue (NATS)
etcd/            → 服务发现 / Service discovery
session/         → 会话管理 / Session management
pb/              → gRPC 客户端 / gRPC client stubs
proto/           → Protobuf 定义 / Protobuf definitions
migrate/         → 数据库迁移 / Database migrations
error.rs         → 统一错误类型 / Unified error types
```

### 基础设施速查 / Infrastructure Quick Reference

| 服务 / Service | 用途 / Purpose                            | 协议 / Protocol |
|--------------|-----------------------------------------|---------------|
| Postgres     | 主数据库 / Primary database                 | sqlx          |
| Redis        | 缓存/会话/限流 / Cache/sessions/rate limiting | redis + r2d2  |
| etcd         | 服务发现 / Service discovery                | etcd-client   |
| NATS         | 消息队列 / Message queue                    | async-nats    |
| S3/MinIO     | 对象存储 / Object storage                   | object_store  |
| Qdrant       | 向量数据库 / Vector DB                       | config only   |

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*This document is maintained by the development team. For questions or suggestions, please open an issue.*