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c4-component
Expert C4 Component-level documentation specialist. Synthesizes C4 Code-level documentation into Component-level architecture, defining component boundaries, interfaces, and relationships.
Try it — you'd type
“Help me with c4-component.”
And you'd get back
Expert C4 Component-level documentation specialist.
Synthesizes C4 Code-level documentation into Component-level architecture, defining component boundaries, interfaces, and relationships.
Adding it takes about 30 seconds
1
Click Get this skill. Grab the .md file, one click, no account needed.
2
Add it to Claude. Drop it into ~/.claude/skills/. Claude picks it up the next time you open a session.
3
Ask normally. Type your question. The skill triggers on the right keywords — you don't have to remember anything.
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SKILL FILEWhat Claude actually reads
## Use this skill when
- Working on c4 component level: [component name] tasks or workflows
- Needing guidance, best practices, or checklists for c4 component level: [component name]
## Do not use this skill when
- The task is unrelated to c4 component level: [component name]
- You need a different domain or tool outside this scope
## Instructions
- Clarify goals, constraints, and required inputs.
- Apply relevant best practices and validate outcomes.
- Provide actionable steps and verification.
- If detailed examples are required, open `resources/implementation-playbook.md`.
## Overview
- **Name**: [Component name]
- **Description**: [Short description of component purpose]
- **Type**: [Component type: Application, Service, Library, etc.]
- **Technology**: [Primary technologies used]
## Purpose
[Detailed description of what this component does and what problems it solves]
## Software Features
- [Feature 1]: [Description]
- [Feature 2]: [Description]
- [Feature 3]: [Description]
## Code Elements
This component contains the following code-level elements:
- c4-code-file-1.md - [Description]
- c4-code-file-2.md - [Description]
## Interfaces
### [Interface Name]
- **Protocol**: [REST/GraphQL/gRPC/Events/etc.]
- **Description**: [What this interface provides]
- **Operations**:
- `operationName(params): ReturnType` - [Description]
## Dependencies
### Components Used
- [Component Name]: [How it's used]
### External Systems
- [External System]: [How it's used]
## Component Diagram
Use proper Mermaid C4Component syntax. Component diagrams show components **within a single container**:
```mermaid
C4Component
title Component Diagram for [Container Name]
Container_Boundary(container, "Container Name") {
Component(component1, "Component 1", "Type", "Description")
Component(component2, "Component 2", "Type", "Description")
ComponentDb(component3, "Component 3", "Database", "Description")
}
Container_Ext(externalContainer, "External Container", "Description")
System_Ext(externalSystem, "External System", "Description")
Rel(component1, component2, "Uses")
Rel(component2, component3, "Reads from and writes to")
Rel(component1, externalContainer, "Uses", "API")
Rel(component2, externalSystem, "Uses", "API")
```
````
**Key Principles** (from [c4model.com](https://c4model.com/diagrams/component)):
- Show components **within a single container** (zoom into one container)
- Focus on **logical components** and their responsibilities
- Show **component interfaces** (what they expose)
- Show how components **interact** with each other
- Include **external dependencies** (other containers, external systems)
````
## Master Component Index Template
```markdown
# C4 Component Level: System Overview
## System Components
### [Component 1]
- **Name**: [Component name]
- **Description**: [Short description]
- **Documentation**: c4-component-name-1.md
### [Component 2]
- **Name**: [Component name]
- **Description**: [Short description]
- **Documentation**: c4-component-name-2.md
## Component Relationships
[Mermaid diagram showing all components and their relationships]
````
## Example Interactions
- "Synthesize all c4-code-\*.md files into logical components"
- "Define component boundaries for the authentication and authorization code"
- "Create component-level documentation for the API layer"
- "Identify component interfaces and create component diagrams"
- "Group database access code into components and document their relationships"
## Key Distinctions
- **vs C4-Code agent**: Synthesizes multiple code files into components; Code agent documents individual code elements
- **vs C4-Container agent**: Focuses on logical grouping; Container agent maps components to deployment units
- **vs C4-Context agent**: Provides component-level detail; Context agent creates high-level system diagrams
## Output Examples
When synthesizing components, provide:
- Clear component boundaries with rationale
- Descriptive component names and purposes
- Comprehensive feature lists for each component
- Complete interface documentation with protocols and operations
- Links to all contained c4-code-\*.md files
- Mermaid component diagrams showing relationships
- Master component index with all components
- Consistent documentation format across all components