Purpose
The design-synthesizer skill provides structured methods for integrating outputs from multiple parallel sub-agents into a cohesive design. It ensures consistency across architecture, library documentation, and dependencies while identifying and resolving conflicts or gaps.
When to Use
This skill auto-activates when you:
- Integrate outputs from multiple parallel sub-agents
- Synthesize architecture design with library documentation
- Align dependencies with architectural requirements
- Check consistency across design documents
- Resolve conflicts between sub-agent outputs
- Identify gaps or missing information in design
- Prepare integrated design for PRP generation
Provided Capabilities
1. Output Integration
- Load Multiple Documents: Read and parse outputs from all sub-agents
- Extract Key Information: Identify critical design elements from each output
- Cross-Reference: Link related elements across different outputs
- Merge Content: Combine information into unified design
2. Consistency Checking
- Architecture-Library Alignment: Verify architecture uses documented library features
- Data Model Validation: Ensure data models match library APIs
- API Contract Verification: Check API designs align with library patterns
- Version Compatibility: Validate library versions match dependency analysis
- Naming Consistency: Ensure consistent terminology across outputs
3. Conflict Resolution
- Identify Mismatches: Find inconsistencies between sub-agent outputs
- Version Conflicts: Resolve dependency version incompatibilities
- Architecture Adjustments: Modify architecture to meet library constraints
- Trade-off Analysis: Document compromises and decisions
- Priority Resolution: Apply priority rules for conflicting requirements
4. Gap Identification
- Missing Documentation: Flag undocumented library features
- Incomplete Dependencies: Identify missing or unresolved dependencies
- Architecture Gaps: Find components without implementation paths
- Unresolved Issues: List conflicts or ambiguities requiring attention
5. Coherent Design Narrative
- Unified Story: Create cohesive narrative across design elements
- Traceability: Link design decisions to requirements
- Rationale Documentation: Explain why specific approaches were chosen
- Implementation Path: Define clear path from design to code
Usage Guide
Step 1: Load Sub-Agent Outputs
Read outputs from all 3 parallel sub-agents:
# Architecture Designer output
/docs/implementation/design/architecture-{issue-number}.md
# Documentation Researcher output
/docs/implementation/design/libraries-{issue-number}.md
# Dependency Manager output
/docs/implementation/design/dependencies-{issue-number}.mdParse Each Output:
- Architecture: Components, data models, API contracts, data flow, error handling
- Libraries: Library versions, API references, code examples, integration patterns
- Dependencies: Dependency tree, versions, compatibility, installation order
Step 2: Extract Key Information
Create structured summary of each output:
From Architecture Designer:
### Architecture Summary
**Components**:
- Component A: [Purpose and responsibilities]
- Component B: [Purpose and responsibilities]
**Data Models**:
- Model X: [Fields, validations, relationships]
- Model Y: [Fields, validations, relationships]
**API Contracts**:
- Endpoint 1: [Method, path, request/response]
- Endpoint 2: [Method, path, request/response]
**Data Flow**:
- Flow 1: [Source → Transform → Destination]
**Error Handling**:
- Strategy: [Approach and patterns]From Documentation Researcher:
### Library Documentation Summary
**Library A (v1.2.3)**:
- Purpose: [What it does]
- Key APIs: [Main functions/classes]
- Code Example: [Integration pattern]
- Best Practices: [Recommended usage]
**Library B (v2.0.0)**:
- Purpose: [What it does]
- Key APIs: [Main functions/classes]
- Code Example: [Integration pattern]
- Known Issues: [Caveats and workarounds]From Dependency Manager:
### Dependency Summary
**Dependency Tree**:
├── library-a==1.2.3
│ ├── dep-x>=2.0
│ └── dep-y<3.0
└── library-b==2.0.0
└── dep-z~=1.5
**Conflicts**: [List of version conflicts]
**Resolution**: [How conflicts were resolved]
**Installation Order**: [Sequence of installation]Step 3: Cross-Reference Design Elements
Map architecture components to libraries and dependencies:
Use synthesis-guide.md for detailed cross-referencing methodology.
Architecture → Libraries Mapping:
### Component A
- **Uses**: Library A (v1.2.3)
- **APIs**: Library A's `ClassX` and `FunctionY`
- **Pattern**: Documented in libraries-{issue-number}.md, section 2.3
- **Code Example**: [Link to example in library docs]
### Data Model X
- **Validation**: Uses Library A's `ValidationMixin`
- **Serialization**: Uses Library B's `Serializer`
- **Storage**: Requires dependency: `database-driver>=3.0`Libraries → Dependencies Mapping:
### Library A (v1.2.3)
- **Required Dependencies**: dep-x>=2.0, dep-y<3.0
- **Optional Dependencies**: dep-optional (for feature Z)
- **Compatibility**: Python 3.9+
- **Conflicts**: None identifiedCross-Reference Matrix:
| Component | Library | Version | Dependencies | Documented |
|---|---|---|---|---|
| Component A | Library A | 1.2.3 | dep-x, dep-y | ✅ |
| Component B | Library B | 2.0.0 | dep-z | ✅ |
| Data Model X | Library A | 1.2.3 | dep-x | ✅ |
Step 4: Check Consistency
Validate alignment across all outputs:
Architecture-Library Consistency:
- ✅ All architecture components reference documented libraries
- ✅ All library APIs used in architecture are documented
- ✅ All data models align with library expectations
- ✅ All API contracts follow library patterns
- ⚠️ Warning: Component C uses undocumented Library API (flag for review)
Library-Dependency Consistency:
- ✅ All libraries have resolved dependencies
- ✅ All dependency versions are compatible
- ✅ No circular dependencies detected
- ⚠️ Conflict: Library A requires dep-x>=2.0, but Library B requires dep-x<2.5 (resolved to 2.4.0)
Naming and Terminology Consistency:
- ✅ Component names consistent across documents
- ✅ Data model names match architecture diagrams
- ⚠️ Inconsistency: Architecture calls it "UserProfile", libraries call it "Profile" (standardize to "UserProfile")
Version Consistency:
- ✅ Library versions match dependency analysis
- ✅ All version constraints satisfied
- ⚠️ Note: Library C has newer version (3.0.0) available, but using 2.8.5 for stability
Step 5: Resolve Conflicts
Use synthesis-guide.md conflict resolution strategies:
Conflict Type 1: Version Incompatibility
**Conflict**: Library A requires dep-x>=2.0, Library B requires dep-x<2.5
**Analysis**: Both constraints can be satisfied with dep-x==2.4.0
**Resolution**: Pin dep-x to 2.4.0 in requirements
**Trade-off**: Cannot use dep-x 2.5+ features until Library B updates
**Risk**: Low - 2.4.0 is stable and well-testedConflict Type 2: Architecture-Library Mismatch
**Conflict**: Architecture designs async API, but Library C only supports sync
**Analysis**: Need to wrap Library C with async adapter or redesign
**Options**:
1. Use asyncio.to_thread() to wrap Library C (simpler, slight overhead)
2. Replace Library C with async alternative (more work, better performance)
**Resolution**: Use asyncio.to_thread() wrapper (priority: speed of implementation)
**Trade-off**: 5-10% performance overhead vs. 2-3 days rewrite
**Mitigation**: Profile performance, optimize if neededConflict Type 3: Missing Documentation
**Conflict**: Architecture uses Library D feature, but no documentation found
**Analysis**: Feature exists in Library D source code but undocumented
**Resolution**:
1. Add note in PRP about undocumented feature
2. Include code example from Library D source
3. Flag for testing during implementation
**Risk**: Medium - undocumented features may change without notice
**Mitigation**: Pin Library D version, add comprehensive testsStep 6: Identify Gaps
Document missing information or unresolved issues:
Gap Analysis:
### Missing Documentation
- Library E's `advanced_feature()` used in architecture but not documented
- Library F's error handling patterns unclear from documentation
### Incomplete Dependencies
- Component G requires database driver, but version not specified
- Testing framework not included in dependency analysis
### Architecture Gaps
- Component H has no implementation path (needs design detail)
- Error handling for API endpoint 3 not specified
### Unresolved Ambiguities
- Data Model Z validation rules conflict with Library requirements
- Performance target not specified for async operationsStep 7: Create Cohesive Design Narrative
Synthesize all information into unified design:
Use design-patterns.md for common patterns and structures.
Synthesized Design Structure:
## Synthesized Design
### Overview
[High-level description of integrated design]
### Component Architecture
[Unified component diagram with library annotations]
**Component A** (uses Library A v1.2.3)
- **Responsibilities**: [What it does]
- **Implementation**: Uses `Library A.ClassX` for [purpose]
- **Dependencies**: dep-x>=2.0, dep-y<3.0
- **Integration**: [How it connects to other components]
**Component B** (uses Library B v2.0.0)
- **Responsibilities**: [What it does]
- **Implementation**: Uses `Library B.ServiceY` for [purpose]
- **Dependencies**: dep-z~=1.5
- **Integration**: [How it connects to other components]
### Data Models (Pydantic Schemas)
**UserProfile Model**from library_a import ValidationMixin from pydantic import BaseModel
class UserProfile(BaseModel, ValidationMixin): id: int name: str email: EmailStr # From library_a # ... fields with library-specific validations
### API Contracts
**Endpoint 1**: `POST /api/users`
- **Implementation**: Uses Library A's `create_user()` method
- **Request**: UserProfile schema
- **Response**: UserProfile with generated ID
- **Error Handling**: Library A's exceptions mapped to HTTP status codes
### Library Integration Strategy
**Library A (v1.2.3)**: User management and validation
- **Integration Point**: Component A, Data Model UserProfile
- **Code Pattern**: [Example from documentation]
- **Error Handling**: Catch `LibraryAException`, return 400/500
**Library B (v2.0.0)**: Background task processing
- **Integration Point**: Component B
- **Code Pattern**: [Example from documentation]
- **Configuration**: [Settings required]
### Dependency Resolution
**Final Dependency Tree**:
library-a==1.2.3 ├── dep-x==2.4.0 # Pinned to resolve conflict ├── dep-y==2.8.0 library-b==2.0.0 ├── dep-z==1.5.3 └── dep-x==2.4.0 # Shared with library-a
**Installation Commands**:
pip install library-a==1.2.3 pip install library-b==2.0.0 pip install -r requirements.txt
### Implementation Path
**Phase 1**: Foundation
1. Install dependencies (in order above)
2. Create data models with Library A validations
3. Set up Library B configuration
**Phase 2**: Core Components
1. Implement Component A using Library A patterns
2. Implement Component B using Library B patterns
3. Test components independently
**Phase 3**: Integration
1. Connect Component A → Component B
2. Implement error handling across components
3. Integration testing
**Phase 4**: Validation
1. Unit tests for each component
2. Integration tests for component interactions
3. Performance testing
### Design Decisions
**Decision 1**: Async Wrapper for Library C
- **Rationale**: Library C only supports sync, but architecture requires async
- **Approach**: Use asyncio.to_thread() wrapper
- **Trade-off**: 5-10% performance overhead vs. 2-3 days to rewrite with async library
- **Risk**: Low - overhead is acceptable for current scale
**Decision 2**: Pin dep-x to 2.4.0
- **Rationale**: Resolve version conflict between Library A and Library B
- **Approach**: Pin to highest compatible version (2.4.0)
- **Trade-off**: Cannot use dep-x 2.5+ features until Library B updates
- **Risk**: Low - 2.4.0 is stable
### Identified Issues
**Issue 1**: Undocumented Library D Feature
- **Description**: Architecture uses Library D's `advanced_feature()`, but not in docs
- **Impact**: Medium - feature may change without notice
- **Mitigation**: Pin Library D version, add comprehensive tests, monitor for updates
**Issue 2**: Component H Implementation Gap
- **Description**: Component H responsibilities defined, but implementation approach unclear
- **Impact**: High - blocks implementation
- **Action Required**: Architecture Designer needs to provide implementation details
### Gaps Requiring Attention
- Resolve Component H implementation approach
- Verify Library D's `advanced_feature()` API stability
- Specify database driver version for Component G
- Clarify performance targets for async operations
- Add testing framework to dependency analysis
Step 8: Validate Synthesis Quality
Quality checklist:
Completeness:
- ✅ All architecture components mapped to libraries
- ✅ All libraries mapped to dependencies
- ✅ All data models have implementation details
- ✅ All API contracts have library integration notes
- ⚠️ Component H needs more detail
Consistency:
- ✅ Terminology consistent across documents
- ✅ Version numbers match everywhere
- ✅ Component names standardized
- ✅ Dependencies resolved without conflicts
Actionability:
- ✅ Implementation path is clear and specific
- ✅ Installation commands provided
- ✅ Code patterns documented
- ⚠️ Some gaps flagged for resolution
Traceability:
- ✅ Design elements link to requirements
- ✅ Library choices justified
- ✅ Design decisions documented with rationale
Best Practices
1. Start with Overview
- Read all outputs completely before synthesis
- Create summary of each output
- Identify major themes and patterns
2. Map Systematically
- Use structured templates for mapping
- Create traceability matrices
- Document every cross-reference
3. Validate Early
- Check consistency as you integrate
- Flag issues immediately
- Don't ignore small discrepancies
4. Resolve Conflicts Transparently
- Document all conflicts found
- Explain resolution reasoning
- Note trade-offs and risks
5. Identify All Gaps
- Missing documentation
- Incomplete specifications
- Unresolved ambiguities
- Assumptions that need validation
6. Create Unified Narrative
- Tell coherent story from architecture → libraries → dependencies → implementation
- Link every design element to requirements
- Provide clear implementation path
Resources
synthesis-guide.md
Comprehensive guide for synthesizing sub-agent outputs including:
- Cross-referencing methodology
- Consistency checking procedures
- Conflict resolution strategies
- Gap identification techniques
- Quality validation criteria
design-patterns.md
Common design patterns and structures including:
- Component integration patterns
- Library usage patterns
- Dependency management patterns
- Error handling patterns
- Testing patterns
Example Usage
Input (Sub-Agent Outputs)
Architecture Designer Output:
## Components
- **UserService**: Handles user CRUD operations
- **TaskQueue**: Manages background tasks
## Data Models
- **User**: id, name, email, created_at
- **Task**: id, task_type, status, payload
## APIs
- POST /api/users: Create user
- POST /api/tasks: Queue background taskDocumentation Researcher Output:
## Libraries
**SQLAlchemy (v2.0.0)**: ORM for database
- User model: Use `declarative_base()` pattern
- Example: [Code snippet]
**Celery (v5.3.0)**: Background task queue
- Task definition: Use `@app.task` decorator
- Example: [Code snippet]Dependency Manager Output:
## Dependencies
sqlalchemy==2.0.0
├── greenlet>=2.0
celery==5.3.0
├── kombu>=5.3
└── billiard>=4.0
Conflict: greenlet version (resolved to 2.0.2)Output (Synthesized Design)
## Synthesized Design
### Component Architecture
**UserService** (uses SQLAlchemy v2.0.0)
- **Implementation**: SQLAlchemy `declarative_base()` pattern
- **Dependencies**: sqlalchemy==2.0.0, greenlet==2.0.2
- **Data Model**: User class inherits from SQLAlchemy Base
**TaskQueue** (uses Celery v5.3.0)
- **Implementation**: Celery `@app.task` decorator
- **Dependencies**: celery==5.3.0, kombu>=5.3, billiard>=4.0
- **Integration**: Tasks defined in tasks.py, queued via TaskQueue service
### Data Models (SQLAlchemy + Pydantic)
from sqlalchemy import declarative_base from pydantic import BaseModel
Base = declarative_base()
class User(Base): __tablename__ = 'users' id: int name: str email: str # With SQLAlchemy validation created_at: datetime
### Library Integration
**SQLAlchemy**: Use declarative_base() for User model (documented pattern) **Celery**: Define tasks with @app.task, configure broker in settings
### Dependencies (Resolved)
sqlalchemy==2.0.0 ├── greenlet==2.0.2 # Pinned to resolve conflict celery==5.3.0 ├── kombu>=5.3 └── billiard>=4.0
Installation:
pip install sqlalchemy==2.0.0 celery==5.3.0
### Design Decisions
**Decision**: Pin greenlet to 2.0.2
- **Rationale**: Resolve version conflict between SQLAlchemy and system
- **Risk**: Low
Integration
This skill is used by:
- design-orchestrator agent during Phase 2: Design & Planning
- Activates automatically when orchestrator synthesizes sub-agent outputs
- Provides unified design for PRP generation (prp-generator skill)
Version: 2.0.0 Auto-Activation: Yes (when synthesizing sub-agent outputs) Phase: 2 (Design & Planning) Created: 2025-10-29