Tech Spec Skill

Trigger

• Keywords: tech spec, technical specification, spec review, review spec, feature design

When NOT to Use

• Creating request documents (use /create-request)
• Code implementation (use feature-dev)
• Architecture consulting (use /codex-architect)

Commands

Command	Purpose	When
/tech-spec	Create or update tech spec	Auto-detects create/update from filesystem state
/deep-analyze	Deepen spec + roadmap	After initial concept
/review-spec	Review tech spec	Spec confirmation

Context-Aware Mode (Upsert)

When invoked without a full requirement description, the skill auto-detects the target feature using the 5-level cascade from references/feature-context-resolution.md.

Filesystem State	Action
docs/features/<key>/2-tech-spec.md exists	Update mode: read existing spec, research code changes since last update, incrementally update changed sections
docs/features/<key>/2-tech-spec.md absent	Create mode: generate new spec from template
Feature not resolved	Gate: Need Human

In update mode, focus on sections affected by recent code changes (use git diff to identify). Preserve unchanged sections.

Workflow

sequenceDiagram
    participant A as Analyst
    participant C as Codebase
    participant D as Document

    A->>A: 1. Requirement clarification
    A->>C: 2. Code research
    C-->>A: Related modules
    A->>A: 3. Solution design
    A->>A: 4. Risk assessment
    A->>A: 5. Work breakdown
    A->>D: 6. Output document

Spec Structure

1. Requirement summary (problem + goals + scope)
2. Existing code analysis
3. Technical solution (architecture + data model + API + core logic)
4. Risks and dependencies
5. Work breakdown
6. Testing strategy
7. Open questions

Output

Numbered tech spec document with sections: Overview, Requirements, Architecture, Implementation plan, Work breakdown, Testing strategy, Open questions.

Verification

• Solution covers all requirement points
• Architecture diagrams use Mermaid
• Risks have mitigation strategies
• Work can be broken into trackable items

References

• references/template.md - Spec template + review dimensions

File Location

docs/features/{feature}/
├── 2-tech-spec.md    # Technical spec (numbered per docs-numbering rule)
├── requests/         # Request documents
└── README.md         # Feature description

Examples

Input: /tech-spec "Implement user asset snapshot feature"
Action: Requirement clarification -> Code research -> Solution design -> Output document

Input: /review-spec docs/features/xxx/2-tech-spec.md
Action: Read -> Research -> Review -> Output report + Gate