OpenSpec Constitution Guard

This skill ensures OpenSpec workflows enforce project-specific quality assurance criteria derived from AGENTS.md constitution files by injecting them into openspec/config.yaml.

Purpose

OpenSpec workflows (/opsx:apply, /opsx:verify, /opsx:archive, etc.) include generic validation. This skill enriches them with project-specific quality gates extracted from AGENTS.md files across the workspace, ensuring all artifacts pass the project's defined testing and QA criteria before handoff.

When to Use

Trigger this skill when:

• Initializing openspec for the first time in a project (openspec init)
• An AGENTS.md file is created, modified, or deleted in the project
• User explicitly requests to sync constitution quality gates with openspec config
• Validating that openspec configuration is up-to-date with constitution requirements

Detection: When to Run

To detect if guards need composition:

1. Check if openspec/config.yaml exists
2. Look for <!-- CONSTITUTION-GUARD:START marker in the config file
3. If marker is missing → first-time setup needed
4. If AGENTS.md files have changed since Last Updated date → refresh needed

Workflow

Step 1: Locate All Constitution Files

Find all AGENTS.md files in the workspace:

find . -name "AGENTS.md" -type f | grep -v node_modules | grep -v .venv | grep -v target | grep -v openspec/AGENTS.md

Exclude openspec/AGENTS.md as it contains OpenSpec usage instructions already referenced by the system, not project-specific quality criteria.

Read each remaining file to understand its scope (root project, backend, frontend, specific module, etc.).

Step 2: Read and Understand Quality Criteria

For each AGENTS.md file, identify sections related to quality assurance. Look for:

• Headings containing: "Quality", "Testing", "Checks", "Validation", "Assurance", "Checklist"
• Command examples (typically in backticks or code blocks)
• Goals or acceptance criteria (e.g., "Zero errors", "All tests pass")
• Architecture patterns and coding standards that should be enforced

Key information to extract:

1. Automated commands - What tools/commands must be run (e.g., pytest, npm run lint)
2. Success criteria - What constitutes passing (e.g., "zero warnings")
3. Architecture rules - Patterns that must be followed (e.g., "service layer separation")
4. Testing requirements - Coverage expectations, test types needed
5. Stack identification - What technology stack does this constitution govern

Step 3: Interpret Criteria for Artifacts

Map the extracted criteria to specific OpenSpec artifacts in the config.yaml rules:

For proposal Artifact

Extract rules that validate design decisions:

• Architecture patterns that must be followed
• Type safety requirements
• Naming conventions
• What requires a proposal vs direct fix
• Breaking change documentation requirements

For specs Artifact

Extract rules that validate specification quality:

• Required sections in specs
• Format requirements (e.g., "Given/When/Then")
• Edge cases that must be documented
• API contract requirements

For design Artifact

Extract rules that validate technical design:

• Design patterns to follow
• System architecture requirements
• Integration points to consider
• Technology choices and their justification

For tasks Artifact

Extract rules that validate implementation planning:

• Task breakdown requirements
• Testing tasks that must be included
• Documentation tasks
• Deployment considerations

For General Context

Extract information that should be available to all artifacts:

• Tech stack information
• Coding conventions
• Team practices
• Backwards compatibility requirements

Step 4: Compose the config.yaml

Create or update openspec/config.yaml with the constitution guards. The file should include:

1. Context section: Project-wide information injected into ALL artifacts
2. Rules section: Per-artifact specific validation rules
3. Constitution metadata: Source files and update timestamp

Template structure:

# openspec/config.yaml

# Schema selection (if you have a preferred one)
schema: spec-driven

# <!-- CONSTITUTION-GUARD:START - Auto-generated from AGENTS.md files -->
# Context injected into ALL artifacts
context: |
  [PROJECT-WIDE CONTEXT]

# Per-artifact validation rules
rules:
  proposal:
    - [PROPOSAL-SPECIFIC RULES]
  
  specs:
    - [SPECS-SPECIFIC RULES]
  
  design:
    - [DESIGN-SPECIFIC RULES]
  
  tasks:
    - [TASKS-SPECIFIC RULES]

# Constitution metadata
# Source Constitutions:
# - [List each AGENTS.md file path]
# Last Updated: [YYYY-MM-DD]
# <!-- CONSTITUTION-GUARD:END -->

Step 5: Update Configuration File

1. Check if openspec/config.yaml exists
   • If not, create it with initial configuration
   • If yes, read current content
2. Locate the <!-- CONSTITUTION-GUARD:START marker
3. If existing guard block found, replace it entirely
4. If no existing block, append to the file
5. Preserve any existing schema: declaration at the top
6. Ensure proper YAML formatting is maintained

Critical: Always validate YAML syntax after generation to ensure the file is parseable.

Example Outputs

Example: Basic Configuration

After reading constitutions with Python backend and TypeScript frontend:

# openspec/config.yaml

schema: spec-driven

# <!-- CONSTITUTION-GUARD:START - Auto-generated from AGENTS.md files -->
# Context injected into ALL artifacts
context: |
  Tech stack: Python (FastAPI, Pydantic), TypeScript (React, Node.js), PostgreSQL
  Architecture: Service layer pattern - business logic in services/, API routes are thin
  Type safety: Strict typing required (no Any/any types)
  API style: RESTful with OpenAPI docs
  Testing: pytest + React Testing Library
  We value backwards compatibility for all public APIs

# Per-artifact validation rules
rules:
  proposal:
    - Include rollback plan for breaking changes
    - Mark breaking changes with **BREAKING** prefix
    - Identify affected teams/systems
    - Verify alignment with service layer architecture
  
  specs:
    - Use Given/When/Then format for scenarios
    - Document all edge cases and error conditions
    - Reference existing patterns before proposing new ones
    - Include API contract changes if applicable
  
  design:
    - Maintain service layer separation (logic in services/, not api/)
    - Use Pydantic models for all new data structures
    - Ensure strict typing (no Any types in Python/TypeScript)
    - Document integration points with existing services
  
  tasks:
    - Include unit test tasks for all new service logic
    - Include integration test tasks for API changes
    - Add type checking verification tasks
    - Include documentation update tasks

# Source Constitutions:
# - AGENTS.md
# - backend/AGENTS.md
# - frontend/AGENTS.md
# Last Updated: 2026-02-09
# <!-- CONSTITUTION-GUARD:END -->

Example: With Automated Check Commands

After reading constitutions with specific test commands:

# openspec/config.yaml

schema: spec-driven

# <!-- CONSTITUTION-GUARD:START - Auto-generated from AGENTS.md files -->
context: |
  Tech stack: Python (uv, FastAPI), TypeScript (Vite, React), PostgreSQL
  Automated checks required before completion:
  - Python: uv run pytest, uv run ruff check ., uv run pyright .
  - TypeScript: npm run lint, npm run tsc, npx playwright test
  Architecture: Microservices with event-driven communication
  All services must be independently deployable

rules:
  proposal:
    - Identify service boundaries affected
    - Document event schema changes
    - Include deployment strategy
    - Consider backwards compatibility for events
  
  specs:
    - Document event payloads in Given/When/Then scenarios
    - Include failure/retry scenarios
    - Specify service dependencies
  
  design:
    - Show event flow diagrams for cross-service changes
    - Use async/await patterns for I/O operations
    - Maintain service independence
  
  tasks:
    - Before marking complete, run: uv run pytest (Python)
    - Before marking complete, run: npm run lint && npm run tsc (TypeScript)
    - Include E2E test tasks for cross-service scenarios
    - Add event contract validation tasks

# Source Constitutions:
# - AGENTS.md
# - services/user/AGENTS.md  
# - services/order/AGENTS.md
# Last Updated: 2026-02-09
# <!-- CONSTITUTION-GUARD:END -->

Example: Complex Multi-Stack Project

After reading constitutions from root, backend (Python), frontend (React), and mobile (Swift):

# openspec/config.yaml

schema: spec-driven

# <!-- CONSTITUTION-GUARD:START - Auto-generated from AGENTS.md files -->
context: |
  Multi-platform project with shared API
  
  Backend (Python):
  - FastAPI + SQLAlchemy + Alembic
  - Service layer required for all business logic
  - Commands: uv run pytest, uv run ruff check ., uv run mypy .
  
  Web Frontend (TypeScript/React):
  - Vite + React + TanStack Query
  - Commands: npm run lint, npm run type-check, npm test
  
  Mobile (Swift):
  - SwiftUI + Combine
  - Commands: swift test, swiftlint
  
  Shared API contracts documented in docs/api/
  Zero tolerance for breaking changes without migration plan

rules:
  proposal:
    - Mark platform scope (backend/web/mobile/api)
    - For API changes, document impact on all clients
    - Include migration strategy for breaking changes
    - Specify API versioning approach if needed
  
  specs:
    - Use platform-specific scenario tags: [Backend], [Web], [Mobile]
    - Document API contract changes in OpenAPI format
    - Include backwards compatibility scenarios
    - Reference existing patterns from project codebase
  
  design:
    - Show component/service interaction diagrams
    - Maintain service layer in backend (no logic in routes)
    - Use proper state management patterns per platform
    - Document data flow for cross-platform features
  
  tasks:
    - Group tasks by platform with clear labels
    - Backend: Include pytest, ruff, mypy verification
    - Web: Include lint, type-check, unit test tasks
    - Mobile: Include SwiftLint and unit test tasks
    - For API changes, include contract validation task
    - Include platform-specific E2E test tasks

# Source Constitutions:
# - AGENTS.md
# - backend/AGENTS.md
# - frontend/AGENTS.md
# - mobile/AGENTS.md
# Last Updated: 2026-02-09
# <!-- CONSTITUTION-GUARD:END -->

Interpretation Guidelines

When reading AGENTS.md files with varying structures:

1. Look for imperative language: "MUST", "SHALL", "required", "always"
2. Identify command patterns: Anything in backticks that looks like a shell command
3. Find success criteria: Phrases like "zero errors", "all pass", "no warnings"
4. Recognize stack indicators: Framework names, file extensions, folder names
5. Extract checklists: Bullet points with checkboxes or numbered items

Categorizing Extracted Information

For Context (applies to all artifacts):

• Technology stack descriptions
• Architectural principles
• Naming conventions
• Team practices
• Backwards compatibility requirements
• General coding standards

For Rules (specific to artifacts):

• Specific format requirements (e.g., "Use Given/When/Then")
• Required sections in artifacts
• Validation commands to run
• Architecture patterns to enforce
• Testing requirements
• Documentation standards

If a constitution section is ambiguous, interpret conservatively—include the check rather than omit it.

All constitution items should be derived from project AGENTS.md files only, DO NOT include OpenSpec's own AGENTS.md or any common sense or best practices from other materials.

How OpenSpec Uses the Configuration

When an OpenSpec command generates or works with an artifact, your configuration is automatically injected:

Context Injection (ALL artifacts)

<context>
Tech stack: Python (FastAPI, Pydantic), TypeScript (React, Node.js), PostgreSQL
Architecture: Service layer pattern - business logic in services/, API routes are thin
Type safety: Strict typing required (no Any/any types)
...
</context>

<template>
[Schema's built-in template for this artifact]
</template>

Rules Injection (matching artifact only)

For /opsx:continue proposal or when generating a proposal:

<rules>
- Include rollback plan for breaking changes
- Mark breaking changes with **BREAKING** prefix
- Identify affected teams/systems
- Verify alignment with service layer architecture
</rules>

This ensures every artifact is generated with your project's specific requirements in mind.

Related OpenSpec Commands

Understanding which commands work with which artifacts:

Command	Purpose	Affected Artifacts
/opsx:new	Start a change	Creates change directory
/opsx:continue	Create next artifact	proposal → specs → design → tasks
/opsx:ff	Fast-forward (create all planning)	proposal, specs, design, tasks
/opsx:apply	Implement tasks	Works from tasks.md
/opsx:verify	Validate implementation	Checks against all artifacts
/opsx:sync	Merge specs to main	Updates openspec/specs/
/opsx:archive	Complete change	Finalizes and archives

Your constitution rules in config.yaml affect the quality and validation of artifacts throughout this workflow.

Maintenance

When updating guards:

1. Re-read all AGENTS.md files
2. Extract updated quality criteria
3. Locate the <!-- CONSTITUTION-GUARD:START block in config.yaml
4. Replace the entire block with newly generated content
5. Preserve any existing schema: declaration at the top
6. Validate YAML syntax
7. Update the Last Updated timestamp
8. Test with openspec new test-change to verify configuration loads correctly

Validation After Update

After updating config.yaml, verify it works:

# Check YAML syntax
python -c "import yaml; yaml.safe_load(open('openspec/config.yaml'))"

# Test with a dummy change
openspec new test-validation
# Check if context and rules are properly injected in artifacts

If you see errors about context or rules not being injected, check YAML indentation and structure.