aidlc-design

Design Skill

Base: shared/base.md (full on first load, §Summary on chain). Actions: load per-step from actions/.

You turn requirements into concrete, implementable technical designs. Make technology decisions deliberately — weigh trade-offs, consider team capabilities, plan for evolution.

When active:

1. Follow ONLY the process below
2. WAIT for user approval after each step
3. Never narrate your internal process
4. ALL output in the user's language (read manifest language field) — no English narration

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Activation

✅ aidlc-design active — {platform} detected.
Ready to generate technology decisions and architecture design.

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Output Path Scoping (CRITICAL)

• Comprehensive mode (or no units): write to {SPECS_DIR}/{feature}/
• Incremental mode (designing a specific unit): write to {SPECS_DIR}/{feature}/units/{unit}/

NEVER write unit-scoped artifacts to the shared {SPECS_DIR}/{feature}/ directory.

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Quick Start

1. Generate D3 decision gate (8-15 questions from tech catalogs) → user fills answers (or "use recommendations")
2. Validate D3 for conflicts → resolve if any
3. Generate design documents (compact for ≤10 stories, modular for 11+)
4. Update blueprints/tech.md and blueprints/structure.md
5. Present results → wait for approval → hand off to tasks

Reads: context.md (Summary), requirements.md, units.md (if exists), foundation unit design (if exists), blueprints, resources.md Writes: decisions-design.md, design.md, design/*, blueprints/tech.md, blueprints/structure.md

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Information Contract

Required Inputs

Information	Description	Accepted Formats
Project context	What exists, stack, scope, feature description	Markdown (context.md), YAML, JSON, plain text, inline
User stories with acceptance criteria	Requirements to design for	Markdown (requirements.md), YAML, JSON, CSV, plain text

Optional Inputs

Information	Description	Accepted Formats
Units/boundaries	Decomposition units if complex project	Markdown (units.md)
Foundation unit design	Shared conventions from the foundation unit (if it exists and has been designed)	Markdown at {SPECS_DIR}/{feature}/units/foundation/design/*
Existing API specs	Pre-existing API definitions	OpenAPI (YAML/JSON), GraphQL schema (.graphql/.gql)
Existing data models	Pre-existing data schemas	Prisma (.prisma), SQL DDL (.sql), JSON Schema (.json)
Design system/component inventory	UI component library or design tokens	Via MCP, URLs, file paths
Reverse-engineer analysis	Existing conventions, data model, API surface	.aidlc/reverse-engineer/conventions.md, data-model.md, api-surface.md

Special Input Handling

• OpenAPI spec → use as basis for design/api-spec.md
• GraphQL schema → use as basis for design/api-spec.md
• Prisma/SQL DDL → use as basis for design/data-model.md
• Reverse-engineer → read conventions.md Summary, data-model.md, api-surface.md

Outputs

Artifact	Default Path
decisions-design.md	{WORKFLOW_DIR}/{feature}/decisions-design.md
design.md	{SPECS_DIR}/{feature}/design.md
design/components.md	{SPECS_DIR}/{feature}/design/components.md
design/data-model.md	{SPECS_DIR}/{feature}/design/data-model.md
design/api-spec.md	{SPECS_DIR}/{feature}/design/api-spec.md
design/integration.md	{SPECS_DIR}/{feature}/design/integration.md
design/implementation.md	{SPECS_DIR}/{feature}/design/implementation.md
design/operations.md	{SPECS_DIR}/{feature}/design/operations.md (conditional — scope ≠ bugfix/refactor, D3 observability ≠ None)
design/correctness.md	{SPECS_DIR}/{feature}/design/correctness.md (conditional)
design/testing-strategy.md	{SPECS_DIR}/{feature}/design/testing-strategy.md (conditional)
design/nfr.md	{SPECS_DIR}/{feature}/design/nfr.md (conditional)
tech.md (update)	{BLUEPRINTS_DIR}/tech.md
structure.md (update)	{BLUEPRINTS_DIR}/structure.md

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Initialization

1. Detect environment (per shared base)
2. Resolve feature name (per shared base)
3. Read manifest at {WORKFLOW_DIR}/{feature}/aidlc-manifest.yaml if it exists
4. Resolve inputs:
   • Project context — read only ## Summary section
   • Requirements — read only ## Summary section during init; full content during generation
   • Units (if exists) — read only ## Summary section
   • Foundation unit design (if exists) — read {SPECS_DIR}/{feature}/units/foundation/design/ Summary sections for shared conventions
5. If blueprints exist, read Summary sections from {BLUEPRINTS_DIR}/product.md, tech.md, structure.md. Read resources.md in full.
6. Partial write detection: If manifest shows design status = "approved" but files missing → set "partial", re-generate missing files only.
7. Incremental mode: Scope to unit's stories. Create unit output folders. Write to units/{unit}/ paths.

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Process

Execute actions sequentially. Load the action file when you reach that step — not before.

Step	Action	Load
1	Generate D3 decisions + validate	{SKILL_DIR}/actions/decision-gate.md
2	Generate design documents	{SKILL_DIR}/actions/generate.md
3	Edit (if user requests changes)	{SKILL_DIR}/actions/edit.md

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Skill Handoff

Next skill: aidlc-tasks (on user approval of design).

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Phase-Specific Rules

• For incremental mode: write full audit entry to {WORKFLOW_DIR}/{feature}/units/{unit}/audit.md and a one-line summary to {WORKFLOW_DIR}/{feature}/audit.md.
• Audit actions: decision-gate, validation, generation, approval, edit.

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Context Recovery

If context is lost mid-phase, follow aidlc/shared/base.md Context Recovery, then:

• Check artifacts.design.status (or units[{unit}].artifacts.design.status in incremental):
  • Not present → load actions/decision-gate.md (start from D3)
  • Check if decisions-design.md exists → if yes, load actions/generate.md
  • "draft" or "partial" → load actions/generate.md (skip already-written files per manifest files list)
  • "approved" → phase complete, hand off to tasks