name: doc-ctr
description: Create Data Contracts (CTR) - Optional Layer 9 artifact using dual-file format (.md + .yaml) for API/data contracts
tags:
- sdd-workflow
- layer-9-artifact
- shared-architecture
custom_fields:
layer: 9
artifact_type: CTR
architecture_approaches: [ai-agent-based, traditional-8layer]
priority: shared
development_status: active
skill_category: core-workflow
upstream_artifacts: [BRD,PRD,EARS,BDD,ADR,SYS,REQ,IMPL]
downstream_artifacts: [SPEC,TASKS,Code]

doc-ctr

Purpose

Create Data Contracts (CTR) - Optional Layer 9 artifact in the SDD workflow that defines API contracts, data schemas, and interface specifications using dual-file format (markdown + YAML).

Layer: 9 (Optional)

Upstream: BRD (Layer 1), PRD (Layer 2), EARS (Layer 3), BDD (Layer 4), ADR (Layer 5), SYS (Layer 6), REQ (Layer 7), IMPL (Layer 8)

Downstream Artifacts: SPEC (Layer 10), TASKS (Layer 11), Code (Layer 12)

Prerequisites

Upstream Artifact Verification (CRITICAL)

Before creating this document, you MUST:

1. List existing upstream artifacts:
   bash ls docs/BRD/ docs/PRD/ docs/EARS/ docs/BDD/ docs/ADR/ docs/SYS/ docs/REQ/ docs/IMPL/ 2>/dev/null

2. Reference only existing documents in traceability tags

3. Use null only when upstream artifact type genuinely doesn't exist
4. NEVER use placeholders like BRD-XXX or TBD
5. Do NOT create missing upstream artifacts - skip functionality instead

Before creating CTR, read:

1. Shared Standards: .claude/skills/doc-flow/SHARED_CONTENT.md
2. Upstream REQ: Read atomic requirements (especially Section 3: Interface Specifications, Section 4: Data Schemas)
3. Template: ai_dev_flow/CTR/CTR-TEMPLATE.md and CTR-TEMPLATE.yaml
4. Creation Rules: ai_dev_flow/CTR/CTR_CREATION_RULES.md
5. Validation Rules: ai_dev_flow/CTR/CTR_VALIDATION_RULES.md
6. Validation Script: ./ai_dev_flow/scripts/validate_ctr.sh

Reserved ID Exemption (CTR-00_*)

Scope: Documents with reserved ID 000 are FULLY EXEMPT from validation.

Pattern: CTR-00_*.md, CTR-00_*.yaml

Document Types:
- Index documents (CTR-00_index.md)
- Traceability matrix templates (CTR-00_TRACEABILITY_MATRIX-TEMPLATE.md)
- Glossaries, registries, checklists

Rationale: Reserved ID 000 documents are framework infrastructure (indexes, templates, reference materials), not project artifacts requiring traceability or quality gates.

Validation Behavior: Skip all checks when filename matches CTR-00_* pattern.

When to Use This Skill

Use doc-ctr when:
- Have completed BRD through REQ (Layers 1-7)
- Need to define API contracts or data schemas
- Multiple teams/services need shared contracts
- Building microservices or distributed systems
- REQ Section 3 (Interface Specifications) needs formal contract
- This layer is OPTIONAL - skip if contracts are simple

CTR-Specific Guidance

1. Mandatory Dual-File Format

Two files required for each contract (mandatory dual-file format: .md file + companion .yaml file):

Markdown File (.md):
- Document Control section
- Contract overview
- Business context
- Usage examples
- Traceability

YAML File (.yaml):
- OpenAPI 3.0 or JSON Schema
- Formal contract definition
- Validation rules
- Example payloads

Example:

ai_dev_flow/CTR/CTR-01_data_validation.md
ai_dev_flow/CTR/CTR-01_data_validation.yaml

2. Document Control Fields (9 Required)

3. Required Sections (Markdown File)

Document Control (MANDATORY - First section before all numbered sections)

Core Sections:
1. Contract Overview: Purpose, scope, version
2. Business Context: Why this contract exists (link to REQ)
3. Contract Definition: Reference to YAML file
4. Usage Examples: Request/response examples
5. Validation Rules: Schema validation, business rules
6. Error Handling: Error codes and responses
7. Traceability: Section 7 format with cumulative tags

4. Element ID Format (MANDATORY)

Pattern: CTR.{DOC_NUM}.{ELEM_TYPE}.{SEQ} (4 segments, dot-separated)

REMOVED PATTERNS - Do NOT use legacy formats:
- INT-XXX - Use CTR.NN.16.SS instead
- MODEL-XXX - Use CTR.NN.17.SS instead
- CLAUSE-XXX - Use CTR.NN.20.SS instead
- IF-XXX - Use CTR.NN.16.SS instead
- DM-XXX - Use CTR.NN.17.SS instead
- CC-XXX - Use CTR.NN.20.SS instead

Reference: ID_NAMING_STANDARDS.md - Cross-Reference Link Format

5. YAML Contract Format

OpenAPI 3.0 Format (for APIs):

openapi: 3.0.3
info:
  title: Data Validation API
  version: 1.0.0
  description: Contract for data validation

paths:
  /api/v1/data/validate:
    post:
      summary: Validate data record
      operationId: validateDataRecord
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/DataRequest'
      responses:
        '200':
          description: Validation successful
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationResponse'
        '400':
          description: Invalid request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'

components:
  schemas:
    DataRequest:
      type: object
      required:
        - record_type
        - record_id
        - data
        - account_id
      properties:
        record_type:
          type: string
          pattern: ^[A-Z]{1,10}$
          example: "METRIC"
        record_id:
          type: string
          format: uuid
          example: "abc123"
        data:
          type: object
          example: {}
        account_id:
          type: string
          format: uuid
          example: "123e4567-e89b-12d3-a456-426614174000"

    ValidationResponse:
      type: object
      required:
        - valid
        - order_id
      properties:
        valid:
          type: boolean
          example: true
        order_id:
          type: string
          format: uuid
          example: "987f6543-e21c-43d2-b654-426614174111"
        warnings:
          type: array
          items:
            type: string
          example: ["Price near market close"]

    ErrorResponse:
      type: object
      required:
        - error_code
        - message
      properties:
        error_code:
          type: string
          example: "INVALID_SYMBOL"
        message:
          type: string
          example: "Symbol 'XYZ' not found in approved list"
        details:
          type: object
          additionalProperties: true

JSON Schema Format (for data models):

$schema: "http://json-schema.org/draft-07/schema#"
name: DataProcessingConfig
description: Configuration schema for data processing

type: object
required:
  - max_batch_size
  - timeout_seconds
  - check_frequency

properties:
  max_batch_size:
    type: integer
    minimum: 1
    maximum: 10000
    description: Maximum records per batch
    example: 1000

  timeout_seconds:
    type: integer
    minimum: 1
    maximum: 300
    description: Processing timeout in seconds
    example: 60

  check_frequency:
    type: string
    enum: ["realtime", "1min", "5min", "15min"]
    description: How often to check processing status
    example: "1min"

  alert_threshold:
    type: number
    minimum: 0
    maximum: 1.0
    description: Alert when queue depth exceeds this fraction
    default: 0.80
    example: 0.80

6. Usage Examples Section

Format:

## Usage Examples

### Example 1: Successful Validation

**Request**:
```json
{
  "record_type": "METRIC",
  "record_id": "abc123",
  "data": {"value": 100},
  "account_id": "123e4567-e89b-12d3-a456-426614174000"
}

Response:

{
  "valid": true,
  "order_id": "987f6543-e21c-43d2-b654-426614174111",
  "warnings": []
}

Example 2: Invalid Record Type

Request:

{
  "record_type": "invalid",
  "record_id": "abc123",
  "data": {"value": 100},
  "account_id": "123e4567-e89b-12d3-a456-426614174000"
}

Response (400 Bad Request):

{
  "error_code": "INVALID_RECORD_TYPE",
  "message": "Record type 'invalid' not found in approved list",
  "details": {
    "record_type": "invalid",
    "approved_types": ["METRIC", "EVENT", "LOG"]
  }
}

### 7. Contract Versioning

**Semantic Versioning**: Major.Minor.Patch

**Version Policy**:
- **Major**: Breaking changes (incompatible)
- **Minor**: New features (backward compatible)
- **Patch**: Bug fixes (backward compatible)

**Example**:
```yaml
openapi: 3.0.3
info:
  title: Data Validation API
  version: 2.1.0  # Major.Minor.Patch
  description: |
    Version 2.1.0 (2025-01-15)
    - Added: optional 'warnings' field in response (minor)
    - Fixed: validation error for edge case data (patch)

    Breaking changes from v1.x:
    - Changed: account_id now requires UUID format (was string)

8. SPEC-Ready Scoring System

Purpose: Measures CTR maturity and readiness for progression to Technical Specifications (SPEC) phase.

Format in Document Control:

| **SPEC-Ready Score** | ✅ 95% (Target: ≥90%) |

Status and SPEC-Ready Score Mapping:

Scoring Criteria:
- Schema Completeness (35%): All endpoints/models defined, JSON Schema/OpenAPI validation passes, examples provided
- Error Handling (25%): All error codes documented, retry strategies specified, failure modes covered
- Quality Attributes (20%): Performance targets, SLA requirements, idempotency specified
- Traceability (10%): Upstream REQ/ADR linked, consumer/provider identified
- Documentation (10%): Usage examples, versioning policy, deprecation strategy

Quality Gate: Score <90% blocks SPEC artifact creation.

9. Directory Organization by Service Type

Purpose: Organize contracts by service type for large projects (30+ contracts).

Structure:

CTR/
├── agents/              # Agent-to-agent communication
├── mcp/                 # MCP server contracts
├── infra/               # Infrastructure services
└── shared/              # Cross-cutting contracts

When to Use:
- <10 contracts: Flat directory
- 10-30 contracts: Optional subdirectories
- 30+ contracts: Mandatory subdirectories

Recommendation: Start flat, migrate to subdirectories when 3+ contracts per service type.

Tag Format Convention (By Design)

The SDD framework uses two distinct notation systems for cross-references:

Key Distinction:
- @adr: ADR-033 → Points to the document ADR-033_risk_limit_enforcement.md
- @brd: BRD.17.01.01 → Points to element 01.01 inside document BRD-017.md

Unified Element ID Format (MANDATORY)

For hierarchical requirements (BRD, PRD, EARS, BDD, SYS, REQ, IMPL):
- Always use: TYPE.NN.TT.SS (dot separator, 4-segment unified format)
- Never use: TYPE-NN:NNN (colon separator - DEPRECATED)
- Never use: TYPE.NN.TT (3-segment format - DEPRECATED)

Examples:
- @brd: BRD.17.01.01 ✅
- @brd: BRD.017.001 ❌ (old 3-segment format)

Cumulative Tagging Requirements

Layer 9 (CTR): Must include tags from Layers 1-8 (BRD through IMPL)

Tag Count: 7-8 tags (7 if IMPL skipped, 8 if IMPL included)

Element Type Codes for Cumulative Tags:
| Tag | Artifact | Element Type | Code |
|-----|----------|--------------|------|
| @brd | BRD | Business Requirement | 01 |
| @prd | PRD | Product Feature | 07 |
| @ears | EARS | EARS Statement | 25 |
| @bdd | BDD | Scenario | 14 |
| @adr | ADR | Document reference | (dash notation) |
| @sys | SYS | System Requirement | 26 |
| @req | REQ | Atomic Requirement | 27 |
| @impl | IMPL | Implementation Phase | 29 |

Format (if IMPL included):

## Traceability

**Required Tags** (Cumulative Tagging Hierarchy - Layer 9):
```markdown
@brd: BRD.01.01.03
@prd: PRD.01.07.02
@ears: EARS.01.25.01
@bdd: BDD.01.14.01
@adr: ADR-033, ADR-045
@sys: SYS.01.26.01
@req: REQ.01.27.03
@impl: IMPL.01.29.01

Format (if IMPL skipped):

@brd: BRD.01.01.03
@prd: PRD.01.07.02
@ears: EARS.01.25.01
@bdd: BDD.01.14.01
@adr: ADR-033, ADR-045
@sys: SYS.01.26.01
@req: REQ.01.27.03

Upstream/Downstream Artifacts

Upstream Sources:
- BRD (Layer 1) - Business requirements
- PRD (Layer 2) - Product features
- EARS (Layer 3) - Formal requirements
- BDD (Layer 4) - Test scenarios
- ADR (Layer 5) - Architecture decisions
- SYS (Layer 6) - System requirements
- REQ (Layer 7) - Atomic requirements (PRIMARY SOURCE - especially Section 3)
- IMPL (Layer 8) - Implementation approach (optional)

Downstream Artifacts:
- SPEC (Layer 10) - Technical specifications
- TASKS (Layer 11) - Task breakdown
- Code (Layer 12) - Implementation code
- Tests (Layer 13) - Test suites

Same-Type Document Relationships (conditional):
- @related-ctr: CTR-NN - CTRs sharing API context
- @depends-ctr: CTR-NN - CTR that must be completed first

Validation Checks

Tier 1: Errors (Blocking)

Tier 2: Warnings (Recommended)

Tier 3: Info

Creation Process

Step 1: Read Upstream Artifacts

Focus on REQ Section 3 (Interface Specifications) and Section 4 (Data Schemas).

Step 2: Reserve ID Number

Check ai_dev_flow/CTR/ for next available ID number.

ID Numbering Convention: Start with 2 digits and expand only as needed.
- ✅ Correct: CTR-01, CTR-99, CTR-102
- ❌ Incorrect: CTR-001, CTR-009 (extra leading zero not required)

Step 3: Create CTR Files (Dual Format)

Location Options:
- Flat: docs/CTR/CTR-NN_{slug}.md + .yaml
- Service-based: docs/CTR/{service_type}/CTR-NN_{slug}.md + .yaml

On-Demand Folder Creation: Before saving, create the target directory if needed:

# For 10+ contracts, create service-type subdirectory
mkdir -p docs/CTR/{service_type}/

Service Types (when 10+ contracts):
- agents/ - Agent-to-agent communication
- mcp/ - MCP server contracts
- infra/ - Infrastructure services
- shared/ - Cross-cutting contracts

Example:
- Flat: docs/CTR/CTR-01_data_validation.md + .yaml
- Subdirectory: docs/CTR/agents/CTR-01_data_validation.md + .yaml

Step 4: Fill Document Control Section (Markdown)

Complete all 9 required fields including SPEC-Ready Score.

Step 5: Write Contract Overview (Markdown)

Summarize purpose, scope, and version.

Step 6: Define YAML Contract

Choose format:
- OpenAPI 3.0 for REST APIs
- JSON Schema for data models
- AsyncAPI for event-driven systems (if applicable)

Step 7: Add Usage Examples (Markdown)

Provide request/response examples with explanations.

Step 8: Document Validation Rules (Markdown)

Explain schema validation and business rules.

Step 9: Specify Error Handling (Markdown)

Document error codes and responses.

Step 10: Add Cumulative Tags

Include all 7-8 upstream tags (@brd through @req/impl).

Step 11: Create/Update Traceability Matrix

MANDATORY: Update ai_dev_flow/CTR/CTR-00_TRACEABILITY_MATRIX-TEMPLATE.md

Step 12: Validate CTR

# YAML schema validation
yamllint ai_dev_flow/CTR/CTR-01_*.yaml

# OpenAPI validation
openapi-spec-validator ai_dev_flow/CTR/CTR-01_*.yaml

# Cumulative tagging
python ai_dev_flow/scripts/validate_tags_against_docs.py --artifact CTR-01 --expected-layers brd,prd,ears,bdd,adr,sys,req,impl --strict

Step 13: Commit Changes

Commit both files (.md and .yaml) and traceability matrix.

Validation

Automated Validation

# Quality gates
scripts/validate_quality_gates.sh ai_dev_flow/CTR/CTR-01_*.md

# YAML validation
yamllint ai_dev_flow/CTR/CTR-01_*.yaml

# OpenAPI validation (if using OpenAPI)
openapi-spec-validator ai_dev_flow/CTR/CTR-01_*.yaml

# CTR-specific validation (includes dual-file check)
./ai_dev_flow/scripts/validate_ctr.sh CTR-01

# Cumulative tagging
python ai_dev_flow/scripts/validate_tags_against_docs.py \
  --artifact CTR-01 \
  --expected-layers brd,prd,ears,bdd,adr,sys,req,impl \
  --strict

Manual Checklist

• [ ] Both files created (.md and .yaml)
• [ ] Document Control complete (9 fields)
• [ ] SPEC-Ready Score format correct (✅ NN% (Target: ≥90%))
• [ ] Contract Overview clear
• [ ] Business Context explains why (links to REQ)
• [ ] YAML contract valid (OpenAPI/JSON Schema)
• [ ] Usage Examples comprehensive
• [ ] Error handling documented
• [ ] Validation rules specified
• [ ] Version number semantic (Major.Minor.Patch)
• [ ] Cumulative tags: @brd through @req/impl (7-8 tags)
• [ ] Element IDs use CTR.NN.TT.SS format
• [ ] Traceability matrix updated

Diagram Standards

All diagrams MUST use Mermaid syntax. Text-based diagrams (ASCII art, box drawings) are prohibited.
See: ai_dev_flow/DIAGRAM_STANDARDS.md and mermaid-gen skill.

Common Pitfalls

1. Single file only: Must create BOTH .md and .yaml files
2. Invalid YAML: Must validate with yamllint and openapi-spec-validator
3. Missing examples: Usage Examples section critical for adoption
4. Vague validation: Schema validation must be precise and testable
5. Missing cumulative tags: Layer 9 must include all 7-8 upstream tags
6. Skipping when needed: Don't skip if multiple teams need shared contract
7. Wrong element IDs: Use CTR.NN.TT.SS, not legacy INT-XXX, MODEL-XXX, CLAUSE-XXX
8. Wrong cumulative tag codes: Use correct element type codes (EARS=25, BDD=14, SYS=26, REQ=27, IMPL=29)

Post-Creation Validation (MANDATORY - NO CONFIRMATION)

CRITICAL: Execute this validation loop IMMEDIATELY after document creation. Do NOT proceed to next document until validation passes.

Automatic Validation Loop

LOOP:
  1. Run: python ai_dev_flow/scripts/validate_cross_document.py --document {doc_path} --auto-fix
  2. IF errors fixed: GOTO LOOP (re-validate)
  3. IF warnings fixed: GOTO LOOP (re-validate)
  4. IF unfixable issues: Log for manual review, continue
  5. IF clean: Mark VALIDATED, proceed

Validation Command

# Per-document validation (Phase 1)
python ai_dev_flow/scripts/validate_cross_document.py --document docs/CTR/CTR-NN_slug.md --auto-fix

# Layer validation (Phase 2) - run when all CTR documents complete
python ai_dev_flow/scripts/validate_cross_document.py --layer CTR --auto-fix

Layer-Specific Upstream Requirements

Auto-Fix Actions (No Confirmation Required)

Validation Codes Reference

Quality Gate

Blocking: YES - Cannot proceed to next document until Phase 1 validation passes with 0 errors.

Next Skill

After creating CTR (or skipping this optional layer), use:

doc-spec - Create Technical Specifications (Layer 10)

The SPEC will:
- Reference CTR (if created) or REQ as upstream source
- Include all 8-9 upstream tags
- Use YAML format
- Define implementation details
- Achieve 100% implementation-readiness

Reference Documents

For supplementary documentation related to CTR artifacts:
- Format: CTR-REF-NNN_{slug}.md
- Skill: Use doc-ref skill
- Validation: Minimal (non-blocking)
- Examples: API style guides, contract versioning policies

Related Resources

• Template: ai_dev_flow/CTR/CTR-TEMPLATE.md (primary authority)
• Schema Template: ai_dev_flow/CTR/CTR-TEMPLATE.yaml (machine-readable)
• CTR Creation Rules: ai_dev_flow/CTR/CTR_CREATION_RULES.md
• CTR Validation Rules: ai_dev_flow/CTR/CTR_VALIDATION_RULES.md
• CTR README: ai_dev_flow/CTR/README.md
• OpenAPI Specification: https://spec.openapis.org/oas/v3.0.3
• JSON Schema: https://json-schema.org/
• Shared Standards: .claude/skills/doc-flow/SHARED_CONTENT.md

Section Templates (for documents >25K tokens):
- Index template: ai_dev_flow/CTR/CTR-SECTION-0-TEMPLATE.md
- Content template: ai_dev_flow/CTR/CTR-SECTION-TEMPLATE.md
- Reference: ai_dev_flow/ID_NAMING_STANDARDS.md (Section-Based File Splitting)

Quick Reference

CTR Purpose: Define API contracts and data schemas

Layer: 9 (Optional)

Element ID Format: CTR.NN.TT.SS
- Interface = 16
- Data Model = 17
- Contract Clause = 20

Removed Patterns: INT-XXX, MODEL-XXX, CLAUSE-XXX, IF-XXX, DM-XXX, CC-XXX

Document Control Fields: 9 required

Tags Required: @brd through @req/impl (7-8 tags)

Format: Dual-file (.md + .yaml)

SPEC-Ready Score: ≥90% required for "Active" status

YAML Standards:
- OpenAPI 3.0 for REST APIs
- JSON Schema for data models
- AsyncAPI for event-driven (if applicable)

Key Sections:
- Contract Overview
- Business Context (link to REQ Section 3)
- YAML contract definition
- Usage Examples
- Validation Rules
- Error Handling

Directory Organization: Subdirectories recommended for 30+ contracts

Optional: Skip this layer if contracts are simple or embedded in REQ

Next: doc-spec