Working on c4 context level: system context tasks or workflows
Needing guidance, best practices, or checklists for c4 context level: system context
Do not use this skill when
The task is unrelated to c4 context level: system context
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
.
System Overview
Short Description
[One-sentence description of what the system does]
Long Description
[Detailed description of the system's purpose, capabilities, and the problems it solves]
Personas
[Persona Name]
Type
[Human User / Programmatic User / External System]
Description
[Who this persona is and what they need]
Goals
[What this persona wants to achieve]
Key Features Used
[List of features this persona uses]
System Features
[Feature Name]
Description
[What this feature does]
Users
[Which personas use this feature]
User Journey
[Link to user journey map]
User Journeys
[Feature Name] - [Persona Name] Journey
...
[External System] Integration Journey
...
External Systems and Dependencies
[External System Name]
Type
[Database, API, Service, Message Queue, etc.]
Description
[What this external system provides]
Integration Type
[API, Events, File Transfer, etc.]
Purpose
[Why the system depends on this]
System Context Diagram
[Mermaid diagram showing system, users, and external systems]
Related Documentation
Container Documentation
Component Documentation
Context Diagram Template
According to the C4 model, a System Context diagram shows the system as a box in the center, surrounded by its users and the other systems that it interacts with. The focus is on people (actors, roles, personas) and software systems rather than technologies, protocols, and other low-level details.
Use proper Mermaid C4 syntax:
```mermaid
C4Context
title System Context Diagram
Person(user, "User", "Uses the system to accomplish their goals")
System(system, "System Name", "Provides features X, Y, and Z")
System_Ext(external1, "External System 1", "Provides service A")
System_Ext(external2, "External System 2", "Provides service B")
Rel(system, externalDb, "Reads from and writes to")
Key Principles
(from
c4model.com
):
Focus on
people and software systems
, not technologies
Show the
system boundary
clearly
Include all
users
(human and programmatic)
Include all
external systems
the system interacts with
Keep it
stakeholder-friendly
- understandable by non-technical audiences
Avoid showing technologies, protocols, or low-level details
Example Interactions
"Create C4 Context-level documentation for the system"
"Identify all personas and create user journey maps for key features"
"Document external systems and create a system context diagram"
"Analyze system documentation and create comprehensive context documentation"
"Map user journeys for all key features including programmatic users"
Key Distinctions
vs C4-Container agent
Provides high-level system view; Container agent focuses on deployment architecture
vs C4-Component agent
Focuses on system context; Component agent focuses on logical component structure
vs C4-Code agent
Provides stakeholder-friendly overview; Code agent provides technical code details
Output Examples
When creating context documentation, provide:
Clear system descriptions (short and long)
Comprehensive persona documentation (human and programmatic)
Complete feature lists with descriptions
Detailed user journey maps for all key features
Complete external system and dependency documentation
Mermaid context diagram showing system, users, and external systems
Links to container and component documentation
Stakeholder-friendly documentation understandable by non-technical audiences
Consistent documentation format