Delta 规范
Delta 规范是 OpenSpec 的核心概念，用于指定变更。它们显示相对于当前规范的变化。
Delta 规范格式
Delta 规范使用三个部分来指示变更类型：
# Delta for <领域>
## ADDED Requirements
新添加的需求。
## MODIFIED Requirements
修改的需求。
## REMOVED Requirements
删除的需求。
ADDED Requirements
新添加的需求将被追加到主规范中。
# Delta for UI
## ADDED Requirements
### Requirement: Theme Selection
The system SHALL allow users to choose between light and dark themes.
#### Scenario: Manual toggle
- GIVEN a user on any page
- WHEN the user clicks the theme toggle
- THEN the theme switches immediately
- AND the preference persists across sessions
#### Scenario: System preference
- GIVEN a user with no saved preference
- WHEN the application loads
- THEN the system's preferred color scheme is used
MODIFIED Requirements
修改的需求将替换现有规范中的版本。
# Delta for Auth
## MODIFIED Requirements
### Requirement: Session Timeout
The system SHALL expire sessions after 30 minutes of inactivity.
(Previously: 60 minutes)
#### Scenario: Idle timeout
- GIVEN an authenticated session
- WHEN 30 minutes pass without activity
- THEN the session is invalidated
REMOVED Requirements
删除的需求将从主规范中删除。
# Delta for Auth
## REMOVED Requirements
### Requirement: Remember Me
(Deprecated in favor of 2FA)
完整 Delta 规范示例
# Delta for Auth
## ADDED Requirements
### Requirement: Two-Factor Authentication
The system MUST require a second factor during login.
#### Scenario: OTP required
- GIVEN a user with 2FA enabled
- WHEN the user submits valid credentials
- THEN an OTP challenge is presented
## MODIFIED Requirements
### Requirement: Session Timeout
The system SHALL expire sessions after 30 minutes of inactivity.
(Previously: 60 minutes)
#### Scenario: Idle timeout
- GIVEN an authenticated session
- WHEN 30 minutes pass without activity
- THEN the session is invalidated
## REMOVED Requirements
### Requirement: Remember Me
(Deprecated in favor of 2FA)
Delta 规范工作流
在变更中使用 Delta 规范
- 创建变更
/opsx:propose add-2fa
- 编辑 Delta 规范
编辑 openspec/changes/add-2fa/specs/auth/spec.md：
# Delta for Auth
## ADDED Requirements
### Requirement: Two-Factor Authentication
The system MUST require a second factor during login.
#### Scenario: OTP required
- GIVEN a user with 2FA enabled
- WHEN the user submits valid credentials
- THEN an OTP challenge is presented
- 实施变更
/opsx:apply
- 归档变更
/opsx:archive
在规范合并后
当变更归档后：
- ADDED 需求被追加到主规范
- MODIFIED 需求替换现有版本
- REMOVED 需求从主规范中删除
- 变更文件夹移动 到
openspec/changes/archive/
Delta 规范最佳实践
- 清晰 - 使用清晰、具体的语言
- 完整 - 包含所有必要的场景
- .atomic - 每个 Delta 规范只关注一个领域
- 可追溯 - 指出修改与现有规范的关系
Delta 规范命令
查看 Delta 规范
# 查看当前变更
openspec list
# 查看变更详情
openspec show add-2fa
验证 Delta 规范
# 验证规范格式
openspec validate add-2fa