C4 Context Level: System Context

Use this skill when

●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

1.[Step 1]: [Description]

2.[Step 2]: [Description]

3.[Step 3]: [Description]

...

[External System] Integration Journey

1.[Step 1]: [Description]

2.[Step 2]: [Description]

...

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](./c4-container.md)

●[Component Documentation](./c4-component.md)


## Context Diagram Template

According to the [C4 model](https://c4model.com/diagrams/system-context), 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:

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")

SystemDb(externalDb, "External Database", "Stores data")

Rel(user, system, "Uses")

Rel(system, external1, "Uses", "API")

Rel(system, external2, "Sends events to")

Rel(system, externalDb, "Reads from and writes to")

c4-context

Documentation