V-Model Extension Pack for Spec Kit

Every specification paired with its test. Full traceability.

An extension for GitHub Spec Kit that enforces the V-Model methodology: every development specification has a simultaneously generated, paired testing specification with full traceability.

Features

/speckit.v-model.requirements — Generate traceable requirements (REQ-NNN) from user input or existing spec.md
/speckit.v-model.acceptance — Generate a three-tier Acceptance Test Plan (Test Cases + BDD Scenarios) with deterministic 100% coverage validation
/speckit.v-model.system-design — Decompose requirements into IEEE 1016-compliant system components (SYS-NNN)
/speckit.v-model.system-test — Generate ISO 29119-compliant system test plans (STP/STS)
/speckit.v-model.architecture-design — IEEE 42010/Kruchten 4+1 architecture decomposition (ARCH-NNN) with Logical, Process, Interface, and Data Flow views
/speckit.v-model.integration-test — ISO 29119-4 integration testing (ITP/ITS) with Interface Contract, Data Flow, Fault Injection, and Concurrency techniques
/speckit.v-model.module-design — Detailed module design (MOD-NNN) with pseudocode, state machines, data structures, and error handling views
/speckit.v-model.unit-test — Unit test plans (UTP/UTS) with Statement & Branch Coverage, Boundary Value Analysis, State Transition Testing, and strict isolation
/speckit.v-model.trace — Build a regulatory-grade Quadruple Traceability Matrix (Matrix A + B + C + D)

Installation

Prerequisites

Spec Kit v0.1.0 or higher
A spec-kit project (directory with .specify/ folder)

Method 1: Install from catalog (when available)

specify extension add v-model

Method 2: Install from GitHub release

specify extension add v-model --from https://github.com/leocamello/spec-kit-v-model/archive/refs/tags/v0.4.0.zip

Method 3: Install from local directory (development)

git clone https://github.com/leocamello/spec-kit-v-model.git
specify extension add --dev /path/to/spec-kit-v-model

Verify installation

specify extension list

Usage

Proactive Workflow (Recommended)

The V-Model extension integrates with Spec Kit's core workflow (/speckit.specify → /speckit.plan → /speckit.tasks → /speckit.implement). Use these V-Model commands between the specify and plan steps:

Step 1: /speckit.v-model.requirements          →  Traceable REQ-NNN from spec.md
Step 2: /speckit.v-model.acceptance            →  Paired ATP + SCN with 100% coverage
Step 3: /speckit.v-model.trace                 →  Matrix A (requirements ↔ acceptance)
Step 4: /speckit.v-model.system-design         →  SYS-NNN components (IEEE 1016 views)
Step 5: /speckit.v-model.system-test           →  STP/STS procedures (ISO 29119-4)
Step 6: /speckit.v-model.trace                 →  Matrix A + B (+ system verification)
Step 7: /speckit.v-model.architecture-design   →  ARCH-NNN modules (IEEE 42010/4+1)
Step 8: /speckit.v-model.integration-test      →  ITP/ITS procedures (ISO 29119-4)
Step 9: /speckit.v-model.trace                 →  Matrix A + B + C (architecture traceability)
Step 10: /speckit.v-model.module-design        →  MOD-NNN modules (pseudocode + state machines)
Step 11: /speckit.v-model.unit-test            →  UTP/UTS procedures (white-box techniques)
Step 12: /speckit.v-model.trace                →  Matrix A + B + C + D (full traceability)

Progressive traceability: The /speckit.v-model.trace command is run four times — after each design↔test pair — so coverage gaps are caught at each V-level rather than discovered at the end.

Example — Feature 002: Custom ID Prefix Support

# Before: define the feature with spec-kit core
/speckit.specify Allow users to configure custom ID prefixes (e.g., SRS instead of REQ)

# 1. Generate traceable requirements from the spec
/speckit.v-model.requirements

# 2. Generate acceptance tests — validates 100% coverage automatically
/speckit.v-model.acceptance

# 3. Build traceability matrix (Matrix A: requirements ↔ acceptance)
/speckit.v-model.trace

# 4. Generate system design elements (IEEE 1016 views)
/speckit.v-model.system-design

# 5. Generate system test procedures (ISO 29119-4 techniques)
/speckit.v-model.system-test

# 6. Build traceability matrix (Matrix A + B: + system verification)
/speckit.v-model.trace

# 7. Generate architecture design (IEEE 42010/Kruchten 4+1 views)
/speckit.v-model.architecture-design

# 8. Generate integration tests (ISO 29119-4 integration techniques)
/speckit.v-model.integration-test

# 9. Build traceability matrix (Matrix A + B + C: architecture traceability)
/speckit.v-model.trace

# 10. Generate module design (pseudocode, state machines, data structures)
/speckit.v-model.module-design

# 11. Generate unit test plan (white-box techniques, strict isolation)
/speckit.v-model.unit-test

# 12. Build traceability matrix (Matrix A + B + C + D: full traceability)
/speckit.v-model.trace

# After: continue with spec-kit core
/speckit.plan
/speckit.tasks
/speckit.implement

Each step produces artifacts in specs/{feature}/v-model/:

specs/{feature}/v-model/
├── requirements.md              →  REQ-NNN requirements
├── acceptance-plan.md           →  ATP + SCN test cases
├── system-design.md             →  SYS-NNN components
├── system-test.md               →  STP/STS procedures
├── architecture-design.md       →  ARCH-NNN modules
├── integration-test.md          →  ITP/ITS procedures
├── module-design.md             →  MOD-NNN detailed modules
├── unit-test.md                 →  UTP/UTS unit test procedures
└── traceability-matrix.md       →  Matrix A + B + C + D

Key Principle: Scripts Verify, AI Generates

The V-Model commands use AI (GitHub Copilot) for creative translation — turning specs into requirements and test plans. But all compliance-critical calculations are performed by deterministic scripts:

Concern	Handled by	Why
Generate requirements & test plans	AI (Copilot)	Creative translation from natural language
Validate requirements ↔ acceptance coverage	`validate-requirement-coverage.sh`	Deterministic — regex-based, mathematically correct
Validate system design ↔ system test coverage	`validate-system-coverage.sh`	Deterministic — SYS→STP→STS cross-reference
Validate architecture ↔ integration coverage	`validate-architecture-coverage.sh`	Deterministic — ARCH→ITP→ITS cross-reference
Validate module ↔ unit test coverage	`validate-module-coverage.sh`	Deterministic — ARCH→MOD→UTP→UTS cross-reference
Build traceability matrix	`build-matrix.sh`	Deterministic — audit-grade accuracy, 4 matrices
Detect requirement changes	`diff-requirements.sh`	Deterministic — git-based diff

Command Reference

1. Generate Requirements (Step 1)

/speckit.v-model.requirements Build a user authentication system with OAuth2 support

Outputs specs/{feature}/v-model/requirements.md with traceable REQ-NNN IDs.

2. Generate Acceptance Test Plan (Step 2)

/speckit.v-model.acceptance

Reads requirements.md and generates:

Test Cases (ATP-NNN-X) — logical validation conditions
User Scenarios (SCN-NNN-X#) — BDD Given/When/Then executable steps

Validates 100% coverage via deterministic script (not AI self-assessment).

3. Generate System Design (Step 4)

/speckit.v-model.system-design

Reads requirements.md and generates system-design.md with SYS-NNN components across four IEEE 1016 views (Decomposition, Dependency, Interface, Data Design).

4. Generate System Test Plan (Step 5)

/speckit.v-model.system-test

Reads system-design.md and generates system-test.md with STP-NNN-X test procedures and STS-NNN-X# test steps using ISO 29119-4 techniques.

5. Generate Architecture Design (Step 7)

/speckit.v-model.architecture-design

Reads system-design.md and generates architecture-design.md with ARCH-NNN modules across four IEEE 42010/Kruchten 4+1 views (Logical, Process, Interface, Data Flow).

6. Generate Integration Test Plan (Step 8)

/speckit.v-model.integration-test

Reads architecture-design.md and generates integration-test.md with ITP-NNN-X test procedures and ITS-NNN-X# test steps using four integration techniques (Interface Contract, Data Flow, Fault Injection, Concurrency).

7. Generate Module Design (Step 10)

/speckit.v-model.module-design

Reads architecture-design.md and generates module-design.md with MOD-NNN modules. Each module includes pseudocode (Algorithmic / Logic View), state machine diagrams, internal data structures, and error handling specifications. Modules tagged [EXTERNAL] or [CROSS-CUTTING] are handled with appropriate bypass rules.

8. Generate Unit Test Plan (Step 11)

/speckit.v-model.unit-test

Reads module-design.md and generates unit-test.md with UTP-NNN-X test procedures and UTS-NNN-X# scenarios. Uses white-box techniques (Statement & Branch Coverage, Boundary Value Analysis, State Transition Testing, Equivalence Partitioning) with strict isolation — every external dependency is mocked via Dependency & Mock Registries.

9. Build Traceability Matrix (Step 3/6/9/12)

/speckit.v-model.trace

Uses deterministic scripts (not AI) to build a regulatory-grade quadruple matrix. Run progressively — after acceptance for Matrix A, after system-test for A+B, after integration-test for A+B+C, after unit-test for A+B+C+D.

ID Schema

The ID scheme encodes traceability directly in the identifier:

Layer	Design ID	Test Case ID	Test Step ID	Matrix
Requirements ↔ Acceptance	`REQ-NNN`	`ATP-NNN-X`	`SCN-NNN-X#`	A
System ↔ System Test	`SYS-NNN`	`STP-NNN-X`	`STS-NNN-X#`	B
Architecture ↔ Integration	`ARCH-NNN`	`ITP-NNN-X`	`ITS-NNN-X#`	C
Module ↔ Unit Test	`MOD-NNN`	`UTP-NNN-X`	`UTS-NNN-X#`	D

Category prefixes: NF (Non-Functional), IF (Interface), CN (Constraint). Functional requirements have no prefix (e.g., REQ-NF-001, ATP-NF-001-A).

Each ID is self-documenting — reading SCN-001-A1 tells you: Scenario 1 → of Test Case A → validating Requirement 001. The same lineage applies at every level: ITS-003-A2 → ITP-003-A → ARCH-003, and UTS-001-A1 → UTP-001-A → MOD-001.

For a comprehensive explanation of ID formats, lifecycle, cross-level linking mechanisms, and end-to-end traceability examples, see the Artifact ID Schema Guide.

Configuration

Optional configuration via v-model-config.yml:

output_dir: "v-model"
id_prefixes:
  requirements: "REQ"
  test_cases: "ATP"
  scenarios: "SCN"
  system_components: "SYS"
  system_test_procedures: "STP"
  system_test_steps: "STS"
  architecture_modules: "ARCH"
  integration_test_procedures: "ITP"
  integration_test_steps: "ITS"
  module_designs: "MOD"
  unit_test_procedures: "UTP"
  unit_test_scenarios: "UTS"
coverage_threshold: 100
batch_size: 5

Testing

# BATS tests (Bash scripts)
tests/bats/lib/bats-core/bin/bats tests/bats/*.bats

# Structural eval tests (Python, deterministic)
pip install -e ".[dev]"
pytest tests/evals/ -m structural -v

# LLM-as-judge evals (requires GOOGLE_API_KEY)
GOOGLE_API_KEY=... pytest tests/evals/ -m eval -v

Layer	Tests	What it validates
BATS	91	Bash script logic (setup, coverage, system coverage, architecture coverage, module coverage, matrix, diff)
Pester	91	PowerShell script parity
Structural evals	51	ID format, template conformance, section completeness across all V-levels
LLM-as-judge evals	36	Requirements quality, BDD quality, design quality, traceability (requires API key)

See CONTRIBUTING.md for full details.

Target Audience

Any engineering team wanting rigorous spec + test pairing
Regulated industries (medical devices, automotive, aerospace) needing audit-ready traceability artifacts

License

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 80 Commits
.github		.github
.specify		.specify
commands		commands
docs		docs
media		media
scripts		scripts
specs		specs
templates		templates
tests		tests
.editorconfig		.editorconfig
.gitignore		.gitignore
.gitmodules		.gitmodules
CHANGELOG.md		CHANGELOG.md
CODE_OF_CONDUCT.md		CODE_OF_CONDUCT.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
README.md		README.md
SECURITY.md		SECURITY.md
catalog-entry.json		catalog-entry.json
config-template.yml		config-template.yml
extension.yml		extension.yml
pyproject.toml		pyproject.toml
requirements-dev.txt		requirements-dev.txt

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V-Model Extension Pack for Spec Kit

Every specification paired with its test. Full traceability.

Features

Installation

Prerequisites

Method 1: Install from catalog (when available)

Method 2: Install from GitHub release

Method 3: Install from local directory (development)

Verify installation

Usage

Proactive Workflow (Recommended)

Key Principle: Scripts Verify, AI Generates

Command Reference

1. Generate Requirements (Step 1)

2. Generate Acceptance Test Plan (Step 2)

3. Generate System Design (Step 4)

4. Generate System Test Plan (Step 5)

5. Generate Architecture Design (Step 7)

6. Generate Integration Test Plan (Step 8)

7. Generate Module Design (Step 10)

8. Generate Unit Test Plan (Step 11)

9. Build Traceability Matrix (Step 3/6/9/12)

ID Schema

Configuration

Testing

Target Audience

License

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V-Model Extension Pack for Spec Kit

Every specification paired with its test. Full traceability.

Features

Installation

Prerequisites

Method 1: Install from catalog (when available)

Method 2: Install from GitHub release

Method 3: Install from local directory (development)

Verify installation

Usage

Proactive Workflow (Recommended)

Key Principle: Scripts Verify, AI Generates

Command Reference

1. Generate Requirements (Step 1)

2. Generate Acceptance Test Plan (Step 2)

3. Generate System Design (Step 4)

4. Generate System Test Plan (Step 5)

5. Generate Architecture Design (Step 7)

6. Generate Integration Test Plan (Step 8)

7. Generate Module Design (Step 10)

8. Generate Unit Test Plan (Step 11)

9. Build Traceability Matrix (Step 3/6/9/12)

ID Schema

Configuration

Testing

Target Audience

License

About

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Resources

License

Code of conduct

Contributing

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Releases 4

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