plugins/backend-development/commands/feature-development.md
You MUST follow these rules exactly. Violating any of them is a failure.
.feature-dev/ before the next step begins. Read from prior step files — do NOT rely on context window memory.PHASE CHECKPOINT, you MUST stop and wait for explicit user approval before continuing. Use the AskUserQuestion tool with clear options.subagent_type references use agents bundled with this plugin or general-purpose. No cross-plugin dependencies.Before starting, perform these checks:
Check if .feature-dev/state.json exists:
If it exists and status is "in_progress": Read it, display the current step, and ask the user:
Found an in-progress feature development session:
Feature: [name from state]
Current step: [step from state]
1. Resume from where we left off
2. Start fresh (archives existing session)
If it exists and status is "complete": Ask whether to archive and start fresh.
Create .feature-dev/ directory and state.json:
{
"feature": "$ARGUMENTS",
"status": "in_progress",
"methodology": "traditional",
"complexity": "medium",
"current_step": 1,
"current_phase": 1,
"completed_steps": [],
"files_created": [],
"started_at": "ISO_TIMESTAMP",
"last_updated": "ISO_TIMESTAMP"
}
Parse $ARGUMENTS for --methodology and --complexity flags. Use defaults if not specified.
Extract the feature description from $ARGUMENTS (everything before the flags). This is referenced as $FEATURE in prompts below.
Gather requirements through interactive Q&A. Ask ONE question at a time using the AskUserQuestion tool. Do NOT ask all questions at once.
Questions to ask (in order):
After gathering answers, write the requirements document:
Output file: .feature-dev/01-requirements.md
# Requirements: $FEATURE
## Problem Statement
[From Q1]
## Acceptance Criteria
[From Q2 — formatted as checkboxes]
## Scope
### In Scope
[Derived from answers]
### Out of Scope
[From Q3]
## Technical Constraints
[From Q4]
## Dependencies
[From Q5]
## Methodology: [tdd|bdd|ddd|traditional]
## Complexity: [simple|medium|complex]
Update state.json: set current_step to 2, add "01-requirements.md" to files_created, add step 1 to completed_steps.
Read .feature-dev/01-requirements.md to load requirements context.
Use the Task tool to launch the architecture agent:
Task:
subagent_type: "backend-architect"
description: "Design architecture for $FEATURE"
prompt: |
Design the technical architecture for this feature.
## Requirements
[Insert full contents of .feature-dev/01-requirements.md]
## Deliverables
1. **Service/component design**: What components are needed, their responsibilities, and boundaries
2. **API design**: Endpoints, request/response schemas, error handling
3. **Data model**: Database tables/collections, relationships, migrations needed
4. **Security considerations**: Auth requirements, input validation, data protection, OWASP concerns
5. **Integration points**: How this connects to existing services/systems
6. **Risk assessment**: Technical risks and mitigation strategies
Write your complete architecture design as a single markdown document.
Save the agent's output to .feature-dev/02-architecture.md.
Update state.json: set current_step to "checkpoint-1", add step 2 to completed_steps.
You MUST stop here and present the architecture for review.
Display a summary of the architecture from .feature-dev/02-architecture.md (key components, API endpoints, data model overview) and ask:
Architecture design is complete. Please review .feature-dev/02-architecture.md
1. Approve — proceed to implementation
2. Request changes — tell me what to adjust
3. Pause — save progress and stop here
Do NOT proceed to Phase 2 until the user selects option 1. If they select option 2, revise the architecture and re-checkpoint. If option 3, update state.json status and stop.
Read .feature-dev/01-requirements.md and .feature-dev/02-architecture.md.
Use the Task tool to launch the backend architect for implementation:
Task:
subagent_type: "backend-architect"
description: "Implement backend for $FEATURE"
prompt: |
Implement the backend for this feature based on the approved architecture.
## Requirements
[Insert contents of .feature-dev/01-requirements.md]
## Architecture
[Insert contents of .feature-dev/02-architecture.md]
## Instructions
1. Implement the API endpoints, business logic, and data access layer as designed
2. Include data layer components (models, migrations, repositories) as specified in the architecture
3. Add input validation and error handling
4. Follow the project's existing code patterns and conventions
5. If methodology is TDD: write failing tests first, then implement
6. Include inline comments only where logic is non-obvious
Write all code files. Report what files were created/modified.
Save a summary of what was implemented to .feature-dev/03-backend.md (list of files created/modified, key decisions, any deviations from architecture).
Update state.json: set current_step to 4, add step 3 to completed_steps.
Read .feature-dev/01-requirements.md, .feature-dev/02-architecture.md, and .feature-dev/03-backend.md.
Use the Task tool:
Task:
subagent_type: "general-purpose"
description: "Implement frontend for $FEATURE"
prompt: |
You are a frontend developer. Implement the frontend components for this feature.
## Requirements
[Insert contents of .feature-dev/01-requirements.md]
## Architecture
[Insert contents of .feature-dev/02-architecture.md]
## Backend Implementation
[Insert contents of .feature-dev/03-backend.md]
## Instructions
1. Build UI components that integrate with the backend API endpoints
2. Implement state management, form handling, and error states
3. Add loading states and optimistic updates where appropriate
4. Follow the project's existing frontend patterns and component conventions
5. Ensure responsive design and accessibility basics (semantic HTML, ARIA labels, keyboard nav)
Write all code files. Report what files were created/modified.
Save a summary to .feature-dev/04-frontend.md.
Note: If the feature has no frontend component (pure backend/API), skip this step — write a brief note in 04-frontend.md explaining why it was skipped, and continue.
Update state.json: set current_step to 5, add step 4 to completed_steps.
Read .feature-dev/03-backend.md and .feature-dev/04-frontend.md.
Launch three agents in parallel using multiple Task tool calls in a single response:
5a. Test Suite Creation:
Task:
subagent_type: "test-automator"
description: "Create test suite for $FEATURE"
prompt: |
Create a comprehensive test suite for this feature.
## What was implemented
### Backend
[Insert contents of .feature-dev/03-backend.md]
### Frontend
[Insert contents of .feature-dev/04-frontend.md]
## Instructions
1. Write unit tests for all new backend functions/methods
2. Write integration tests for API endpoints
3. Write frontend component tests if applicable
4. Cover: happy path, edge cases, error handling, boundary conditions
5. Follow existing test patterns and frameworks in the project
6. Target 80%+ code coverage for new code
Write all test files. Report what test files were created and what they cover.
5b. Security Review:
Task:
subagent_type: "security-auditor"
description: "Security review of $FEATURE"
prompt: |
Perform a security review of this feature implementation.
## Architecture
[Insert contents of .feature-dev/02-architecture.md]
## Backend Implementation
[Insert contents of .feature-dev/03-backend.md]
## Frontend Implementation
[Insert contents of .feature-dev/04-frontend.md]
Review for: OWASP Top 10, authentication/authorization flaws, input validation gaps,
data protection issues, dependency vulnerabilities, and any security anti-patterns.
Provide findings with severity, location, and specific fix recommendations.
5c. Performance Review:
Task:
subagent_type: "performance-engineer"
description: "Performance review of $FEATURE"
prompt: |
Review the performance of this feature implementation.
## Architecture
[Insert contents of .feature-dev/02-architecture.md]
## Backend Implementation
[Insert contents of .feature-dev/03-backend.md]
## Frontend Implementation
[Insert contents of .feature-dev/04-frontend.md]
Review for: N+1 queries, missing indexes, unoptimized queries, memory leaks,
missing caching opportunities, large payloads, slow rendering paths.
Provide findings with impact estimates and specific optimization recommendations.
After all three complete, consolidate results into .feature-dev/05-testing.md:
# Testing & Validation: $FEATURE
## Test Suite
[Summary from 5a — files created, coverage areas]
## Security Findings
[Summary from 5b — findings by severity]
## Performance Findings
[Summary from 5c — findings by impact]
## Action Items
[List any critical/high findings that need to be addressed before delivery]
If there are Critical or High severity findings from security or performance review, address them now before proceeding. Apply fixes and re-validate.
Update state.json: set current_step to "checkpoint-2", add step 5 to completed_steps.
Display a summary of testing and validation results from .feature-dev/05-testing.md and ask:
Testing and validation complete. Please review .feature-dev/05-testing.md
Test coverage: [summary]
Security findings: [X critical, Y high, Z medium]
Performance findings: [X critical, Y high, Z medium]
1. Approve — proceed to deployment & documentation
2. Request changes — tell me what to fix
3. Pause — save progress and stop here
Do NOT proceed to Phase 3 until the user approves.
Read .feature-dev/02-architecture.md and .feature-dev/05-testing.md.
Use the Task tool:
Task:
subagent_type: "general-purpose"
description: "Create deployment config for $FEATURE"
prompt: |
You are a deployment engineer. Create the deployment and monitoring configuration for this feature.
## Architecture
[Insert contents of .feature-dev/02-architecture.md]
## Testing Results
[Insert contents of .feature-dev/05-testing.md]
## Instructions
1. Create or update CI/CD pipeline configuration for the new code
2. Add feature flag configuration if the feature should be gradually rolled out
3. Define health checks and readiness probes for new services/endpoints
4. Create monitoring alerts for key metrics (error rate, latency, throughput)
5. Write a deployment runbook with rollback steps
6. Follow existing deployment patterns in the project
Write all configuration files. Report what was created/modified.
Save output to .feature-dev/06-deployment.md.
Update state.json: set current_step to 7, add step 6 to completed_steps.
Read all previous .feature-dev/*.md files.
Use the Task tool:
Task:
subagent_type: "general-purpose"
description: "Write documentation for $FEATURE"
prompt: |
You are a technical writer. Create documentation for this feature.
## Feature Context
[Insert contents of .feature-dev/01-requirements.md]
## Architecture
[Insert contents of .feature-dev/02-architecture.md]
## Implementation Summary
### Backend: [Insert contents of .feature-dev/03-backend.md]
### Frontend: [Insert contents of .feature-dev/04-frontend.md]
## Deployment
[Insert contents of .feature-dev/06-deployment.md]
## Instructions
1. Write API documentation for new endpoints (request/response examples)
2. Update or create user-facing documentation if applicable
3. Write a brief architecture decision record (ADR) explaining key design choices
4. Create a handoff summary: what was built, how to test it, known limitations
Write documentation files. Report what was created/modified.
Save output to .feature-dev/07-documentation.md.
Update state.json: set current_step to "complete", add step 7 to completed_steps.
Update state.json:
status to "complete"last_updated to current timestampPresent the final summary:
Feature development complete: $FEATURE
## Files Created
[List all .feature-dev/ output files]
## Implementation Summary
- Requirements: .feature-dev/01-requirements.md
- Architecture: .feature-dev/02-architecture.md
- Backend: .feature-dev/03-backend.md
- Frontend: .feature-dev/04-frontend.md
- Testing: .feature-dev/05-testing.md
- Deployment: .feature-dev/06-deployment.md
- Documentation: .feature-dev/07-documentation.md
## Next Steps
1. Review all generated code and documentation
2. Run the full test suite to verify everything passes
3. Create a pull request with the implementation
4. Deploy using the runbook in .feature-dev/06-deployment.md