Claude Code CLI
Published on: October 13, 2025
Entity Relationship Diagram
erDiagram
PLUGIN {
string name PK "Unique plugin identifier"
string description
string version
string source_path "Path to plugin files"
}
AGENT {
string name PK "Unique agent identifier"
string description
string model "AI model used (e.g., sonnet)"
string plugin_name FK
}
COMMAND {
string name PK "Unique command identifier"
string description
string allowed_tools
string plugin_name FK
}
HOOK {
string event_name PK "e.g., PreToolUse"
string matcher "Tools to intercept (e.g., 'Edit|Write')"
string command_path "Script to execute"
string plugin_name FK
}
GITHUB_WORKFLOW {
string name PK "Workflow filename"
string trigger_event "e.g., on: issues"
string file_path
}
SCRIPT {
string name PK "Script filename"
string language "e.g., TypeScript"
string file_path
}
GITHUB_ISSUE {
int issue_number PK "The primary identifier on GitHub"
string title
string state "e.g., open, closed"
}
PLUGIN }o--o| AGENT : "is composed of"
PLUGIN }o--o| COMMAND : "is composed of"
PLUGIN }o--o| HOOK : "is composed of"
GITHUB_WORKFLOW ||--o{ SCRIPT : "executes"
GITHUB_WORKFLOW ||--o{ COMMAND : "invokes"
SCRIPT }o--o| GITHUB_ISSUE : "modifies"
COMMAND }o--o| GITHUB_ISSUE : "interacts with"
GITHUB_WORKFLOW }o--o| GITHUB_ISSUE : "is triggered by"
Component Diagram
C4Component title Component Diagram for Claude Code Repository Person(user, "Developer", "Uses Claude Code to automate development tasks.") System_Ext(github, "GitHub", "Hosts the code repository, runs GitHub Actions, and manages issues/PRs.") System_Ext(dev_container, "Dev Container", "Sandboxed development environment with a configured firewall for secure execution.") System(cli, "Claude Code CLI", "The command-line interface and execution engine for Claude.") Container(plugins_container, "Claude Code Plugins", "Manages and provides plugin
functionalityvia marketplace.json") Component(pr_review, "PR Review Toolkit", "Plugin with specialized agents for
comprehensive PR reviews (code, tests, errors).") Component(feature_dev, "Feature Dev", "Plugin with agents for guided
feature development, including code
exploration and architecture.") Component(security_hook, "Security Guidance", "Plugin that hooks into file
edit/write operations to provide
security warnings.") Component(commit_cmds, "Commit Commands", "Plugin providing git workflow
commands like /commit,
/commit-push-pr.") Component(sdk_dev, "Agent SDK Dev", "Plugin for creating and
verifying new Claude Agent
SDK applications.") Container(workflows_container, "GitHub Workflows", "Automated CI/CD processes
defined in .github/workflows that
interact with the repository.") Component(dedupe_workflow, "Issue Dedupe Workflow", "Runs on new issues to
find duplicates by invoking the
/dedupe command.") Component(triage_workflow, "Issue Triage Workflow", "Runs on new issues to
automatically analyze and
apply labels.") Component(auto_close_workflow, "Auto-Close Workflow", "A scheduled job that
executes a script to close stale issues
marked as duplicates.") Component(script_auto_close, "auto-close-duplicates.ts", "TypeScript script that
contains the logic for closing issues
via the GitHub API.") Component(core_commands, "Core Commands", "Built-in commands like /dedupe
and tools for file system operations
(Read, Write, Edit).") %% --- Relationships --- Rel(user, cli, "Executes commands", "e.g., /review-pr, /feature-dev") Rel(cli, plugins_container, "Loads plugins as
defined in marketplace.json") %% Plugin and Command Interactions Rel(pr_review, cli, "Provides review agents") Rel(feature_dev, cli, "Provides feature development agents") Rel(commit_cmds, github, "Uses git & gh tools to manage commits, branches, and PRs") Rel(sdk_dev, cli, "Provides the /new-sdk-app command") Rel(core_commands, github, "Uses the 'gh' tool to find and comment on duplicate issues", "gh issue view/search") Rel(security_hook, core_commands, "Intercepts file edits to check for vulnerabilities", "PreToolUse Hook on Edit/Write") %% Workflow Interactions Rel(dedupe_workflow, core_commands, "Invokes the /dedupe command") Rel(triage_workflow, github, "Applies labels to issues using the GitHub API") Rel(auto_close_workflow, script_auto_close, "Executes the script on a schedule") Rel(script_auto_close, github, "Closes issues via the GitHub API") %% External System Interactions Rel(cli, dev_container, "Runs within the") Rel(dev_container, github, "Allows network access to", "via init-firewall.sh") UpdateLayoutConfig($c4ShapeInRow="3", $c4BoundaryInRow="1")
Sequence Diagram: Build a Feature from a Description
sequenceDiagram
actor Developer
participant ClaudeCLI as Claude Code CLI
participant CodeExplorer as Code Explorer Agent
participant CodeArchitect as Code Architect Agent
participant WriteTool as Write/Edit Tool
participant CodeReviewer as Code Reviewer Agent
Developer->>ClaudeCLI: "Add a user profile page that shows the user's name and email."
activate ClaudeCLI
Note over ClaudeCLI: Phase 1: Understand the Codebase
ClaudeCLI->>CodeExplorer: Analyze existing UI components and user data models.
activate CodeExplorer
CodeExplorer-->>ClaudeCLI: Returns summary of relevant patterns and files.
deactivate CodeExplorer
Note over ClaudeCLI: Phase 2: Create a Plan
ClaudeCLI->>CodeArchitect: Design the new 'UserProfile' component.
activate CodeArchitect
CodeArchitect-->>ClaudeCLI: Returns a detailed implementation plan (files to create/modify).
deactivate CodeArchitect
ClaudeCLI->>Developer: "Here is the plan to create the profile page. Do you approve?"
Developer-->>ClaudeCLI: "Yes, proceed."
Note over ClaudeCLI: Phase 3: Write the Code
loop For each file in the plan
ClaudeCLI->>WriteTool: Create/modify file with generated code.
activate WriteTool
WriteTool-->>ClaudeCLI: File updated successfully.
deactivate WriteTool
end
Note over ClaudeCLI: Phase 4: Verify the Implementation
ClaudeCLI->>CodeReviewer: Review the new code for bugs and adherence to project standards.
activate CodeReviewer
CodeReviewer-->>ClaudeCLI: Review complete. No critical issues found.
deactivate CodeReviewer
ClaudeCLI-->>Developer: "I have implemented the user profile page and verified the code."
deactivate ClaudeCLI
Sequence Diagram: Debug and Fix an Issue
sequenceDiagram
actor Developer
participant ClaudeCLI as Claude Code CLI
participant SearchTool as Grep/Search Tool
participant ReadTool as Read Tool
participant EditTool as Edit Tool
participant FileSystem
Developer->>ClaudeCLI: "I'm getting this error: 'TypeError: cannot read property 'name' of undefined'"
activate ClaudeCLI
note over ClaudeCLI: Phase 1: Analyze Codebase
ClaudeCLI->>SearchTool: Search for the error string and related function names
activate SearchTool
SearchTool-->>ClaudeCLI: Returns list of relevant files (e.g., processData.js)
deactivate SearchTool
ClaudeCLI->>ReadTool: Read the content of 'processData.js'
activate ReadTool
ReadTool->>FileSystem: Access file
FileSystem-->>ReadTool: File content
ReadTool-->>ClaudeCLI: Returns file content
deactivate ReadTool
note over ClaudeCLI: Phase 2: Identify Problem & Propose Fix
ClaudeCLI->>ClaudeCLI: Analyzes code and identifies a missing null check
ClaudeCLI->>Developer: "The error is caused by a missing check for the 'data' object. The fix is to add a guard clause. May I apply it?"
Developer-->>ClaudeCLI: "Yes, go ahead."
note over ClaudeCLI: Phase 3: Implement the Fix
ClaudeCLI->>EditTool: Apply fix to 'processData.js'
activate EditTool
note over EditTool: Adds a null-check guard clause to the file
EditTool->>FileSystem: Applies the change to the file
FileSystem-->>EditTool: Success
EditTool-->>ClaudeCLI: File updated successfully
deactivate EditTool
ClaudeCLI-->>Developer: "The fix has been applied."
deactivate ClaudeCLI
Sequence Diagram for Issue Dedupe Workflow
sequenceDiagram
actor Developer
participant GitHub
participant ClaudeCodeAction as Claude Code Action
participant ClaudeCore as Claude Core Command
participant GitHubAPI as GitHub API
Developer->>GitHub: Opens a new issue
activate GitHub
Note over GitHub: Issue #123 created
GitHub->>ClaudeCodeAction: Triggers 'Claude Issue Dedupe' workflow
deactivate GitHub
activate ClaudeCodeAction
ClaudeCodeAction->>ClaudeCodeAction: 1. Checks out repository
ClaudeCodeAction->>ClaudeCore: 2. Executes with prompt: "/dedupe owner/repo/issues/123"
deactivate ClaudeCodeAction
activate ClaudeCore
Note over ClaudeCore: The '/dedupe' command begins execution
ClaudeCore->>GitHubAPI: 3. Fetches details for issue #123 (gh issue view)
activate GitHubAPI
GitHubAPI-->>ClaudeCore: Returns issue summary
deactivate GitHubAPI
ClaudeCore->>GitHubAPI: 4. Searches for similar open issues (gh search)
activate GitHubAPI
GitHubAPI-->>ClaudeCore: Returns potential duplicates
deactivate GitHubAPI
ClaudeCore->>ClaudeCore: 5. Analyzes results and filters false positives
opt If duplicates are found
ClaudeCore->>GitHubAPI: 6. Posts a comment on issue #123 with findings (gh issue comment)
activate GitHubAPI
GitHubAPI-->>ClaudeCore: Comment posted successfully
deactivate GitHubAPI
end
deactivate ClaudeCore
Sequence Diagram for PreToolUse Hook
sequenceDiagram
actor Developer
participant ClaudeCLI as Claude Code CLI
participant SecurityHook as security_reminder_hook.py
participant WriteTool as Write Tool
participant FileSystem
Developer->>ClaudeCLI: "Create a script that uses child_process.exec()"
activate ClaudeCLI
ClaudeCLI->>ClaudeCLI: Plans to use the 'Write' tool to create the file
Note over ClaudeCLI: Before executing Write, triggers PreToolUse hooks
ClaudeCLI->>SecurityHook: Invokes hook with file content
activate SecurityHook
SecurityHook->>SecurityHook: Analyzes content for security patterns
alt Potential vulnerability found (e.g., 'exec(')
SecurityHook-->>ClaudeCLI: Exits with code 2 (Block execution) & prints warning
ClaudeCLI-->>Developer: Displays security warning to user
else No vulnerability found
SecurityHook-->>ClaudeCLI: Exits with code 0 (Allow execution)
end
deactivate SecurityHook
opt Execution is Allowed
ClaudeCLI->>WriteTool: Executes Write('path/to/script.js', content)
activate WriteTool
WriteTool->>FileSystem: Writes file to disk
FileSystem-->>WriteTool: Success
deactivate WriteTool
WriteTool-->>ClaudeCLI: File written
ClaudeCLI-->>Developer: "I have created the script."
end
deactivate ClaudeCLI
Sequence Diagram for PR Review Workflow
sequenceDiagram
actor Developer
participant ClaudeCLI as Claude Code CLI
participant ReviewPRCmd as review-pr Command
participant GitTool as Git Tool
participant TestAnalyzer as pr-test-analyzer Agent
participant CodeReviewer as code-reviewer Agent
Developer->>ClaudeCLI: "/review-pr"
activate ClaudeCLI
ClaudeCLI->>ReviewPRCmd: Executes the review command
activate ReviewPRCmd
ReviewPRCmd->>GitTool: Get list of changed files (git diff)
activate GitTool
GitTool-->>ReviewPRCmd: Returns changed file paths
deactivate GitTool
Note over ReviewPRCmd: Launches specialized review agents in parallel
par
ReviewPRCmd->>TestAnalyzer: Analyze test coverage for changed files
activate TestAnalyzer
TestAnalyzer-->>ReviewPRCmd: Returns test coverage report
deactivate TestAnalyzer
and
ReviewPRCmd->>CodeReviewer: Review code quality for changed files
activate CodeReviewer
CodeReviewer-->>ReviewPRCmd: Returns code quality report
deactivate CodeReviewer
end
ReviewPRCmd->>ReviewPRCmd: Aggregates reports from all agents
ReviewPRCmd-->>ClaudeCLI: Returns a consolidated summary
deactivate ReviewPRCmd
ClaudeCLI-->>Developer: Displays the final PR review summary
deactivate ClaudeCLI
Sequence Diagram for Auto-Close Workflow
sequenceDiagram
participant Scheduler
participant WorkflowRunner as GitHub Workflow Runner
participant AutoCloseScript as auto-close-duplicates.ts
participant GitHubAPI as GitHub API
Scheduler->>WorkflowRunner: Trigger workflow (daily at 9 AM)
activate WorkflowRunner
WorkflowRunner->>AutoCloseScript: Executes the script
activate AutoCloseScript
loop For each open issue
AutoCloseScript->>GitHubAPI: 1. Fetch comments for an issue
activate GitHubAPI
GitHubAPI-->>AutoCloseScript: Returns comments
deactivate GitHubAPI
AutoCloseScript->>AutoCloseScript: 2. Check for "duplicate" bot comment older than 3 days
AutoCloseScript->>AutoCloseScript: 3. Check for new comments or '👎' reactions
opt Conditions met (stale duplicate)
AutoCloseScript->>GitHubAPI: 4. Close issue as duplicate
activate GitHubAPI
GitHubAPI-->>AutoCloseScript: Success
deactivate GitHubAPI
end
end
deactivate AutoCloseScript
deactivate WorkflowRunner
C4 System Context Diagram
C4Context title System Context Diagram for Claude Code Person(developer, "Developer", "Uses the CLI to write code, manage git workflows, and automate tasks.") System(claude_code_cli, "Claude Code CLI", "An agentic coding assistant that runs in the terminal to help with software development.") System_Ext(github, "GitHub", "Provides code hosting, CI/CD execution (Actions), and issue/PR management.") System_Ext(dev_container, "Dev Container", "Provides a sandboxed, secure, and reproducible development environment.") System_Ext(anthropic_api, "Anthropic API", "Provides the underlying large language models (e.g., Claude 3 Sonnet/Opus) that power the agent's reasoning.") Rel(developer, claude_code_cli, "Uses") Rel(claude_code_cli, anthropic_api, "Makes API calls to", "HTTPS") Rel(claude_code_cli, github, "Interacts with repositories, issues, and PRs via", "git, gh CLI, HTTPS") Rel(claude_code_cli, dev_container, "Runs inside of")
State Machine Diagram for the Interactive CLI
stateDiagram-v2
[*] --> Initializing
Initializing --> AwaitingUserInput: CLI Ready
AwaitingUserInput --> ProcessingPrompt: User submits prompt
ProcessingPrompt --> ExecutingTool: Model decides to use a tool
note right of ProcessingPrompt
The PreToolUse hook runs on this transition.
If the hook blocks execution (exit code 2),
the CLI displays a warning and returns to AwaitingUserInput.
end note
ProcessingPrompt --> StreamingResponse: Model responds with text
ExecutingTool --> AwaitingUserConfirmation: Tool requires permission
AwaitingUserConfirmation --> ExecutingTool: User grants permission
AwaitingUserConfirmation --> StreamingResponse: User denies permission (displays message)
ExecutingTool --> ProcessingPrompt: Tool returns result successfully
ExecutingTool --> ProcessingPrompt: **Tool fails (returns error)**
StreamingResponse --> AwaitingUserInput: Response finished
%% User Interruptions
ProcessingPrompt --> AwaitingUserInput: **User Interrupts (Ctrl+C)**
ExecutingTool --> AwaitingUserInput: **User Interrupts (Ctrl+C)**
StreamingResponse --> AwaitingUserInput: **User Interrupts (Ctrl+C)**
Activity Diagram for Plugin Loading & Command Dispatch
graph TD
subgraph Initialization Phase
A[Start CLI] --> B{Read marketplace.json};
B -- Found and valid --> C[Load Built-in Components];
B -- Not found or invalid --> Z[Exit with Error];
C --> D{Loop: For each plugin};
D -- Next plugin --> E[Discover Agents, Commands, & Hooks];
E --> F[Register Components];
F --> D;
D -- All plugins processed --> G[Initialization Complete];
end
subgraph Command Loop
G --> H[Listen for User Input];
H --> I{Parse Input};
I --> J{Find Matching Command in Registry};
J -- Command Found --> K[Execute Command Handler];
J -- Command Not Found --> L[Display 'Command not found' Error];
K --> H;
L --> H;
end
Deployment Diagram
graph TD
%% Define the nodes and their hierarchy using subgraphs
subgraph host ["Developer's Host Machine (eg Windows/macOS)"]
subgraph docker [Docker/Podman Engine]
subgraph container [Dev Container]
%% Components inside the container
runtime["Node.js Runtime"] -- executes --> script["Claude Code CLI
(Application Script)"]
firewall["Firewall
(Configured by init-firewall.sh)"]
end
end
end
subgraph external [External Systems]
direction LR
github["GitHub API"]
anthropic["Anthropic API"]
end
%% Define the network communication flow
script -- "Makes HTTPS Requests" --> firewall
firewall -- "Allows traffic to" --> github
firewall -- "Allows traffic to" --> anthropic
%% Styling to make the diagram easier to read
style host fill:#e6e6fa,stroke:#333,stroke-width:2px
style docker fill:#d5f5e3,stroke:#333
style container fill:#eaf2f8,stroke:#333
style external fill:#fff0f0,stroke:#333,stroke-width:2px
Data Flow Diagram
graph TD
%% --- Define Node Styles ---
%% Gane-Sarson DFD Notation
classDef process fill:#e9f5ff,stroke:#3670a0,stroke-width:2px;
classDef entity fill:#fff2cc,stroke:#d6b656,stroke-width:2px;
classDef datastore fill:#f5f5f5,stroke:#666,stroke-width:2px,stroke-dasharray: 5 5;
%% --- Define Nodes (Entities, Processes, Data Stores) ---
E_Dev(Developer);
E_GitHub(GitHub System);
P_Create(1.0 Create Issue);
P_Trigger(2.0 Trigger Workflow);
P_Execute(3.0 Execute Dedupe Command);
P_Analyze(4.0 Analyze Duplicates);
P_Post(5.0 Post Comment);
DS_Issues([GitHub Issues Database]);
%% --- Apply Styles to Nodes ---
class E_Dev,E_GitHub entity;
class P_Create,P_Trigger,P_Execute,P_Analyze,P_Post process;
class DS_Issues datastore;
%% --- Define Data Flows (Arrows with Labels) ---
%% 1. Issue Creation
E_Dev -- "New Issue Data" --> P_Create;
P_Create -- "Submitted Issue Record" --> DS_Issues;
%% 2. Workflow Trigger
DS_Issues -- "Issue Creation Event" --> E_GitHub;
E_GitHub -- "Issue Number" --> P_Trigger;
P_Trigger -- "Start Signal" --> P_Execute;
%% 3. Dedupe Command Execution
P_Execute -- "Request for Issue by Number" --> DS_Issues;
DS_Issues -- "Issue Content" --> P_Execute;
P_Execute -- "Duplicate Search Query" --> DS_Issues;
DS_Issues -- "Potential Duplicates List" --> P_Execute;
%% 4. Analysis and Commenting
P_Execute -- "Content & Duplicates List" --> P_Analyze;
P_Analyze -- "Formatted Duplicate Comment" --> P_Post;
P_Post -- "New Comment Record" --> DS_Issues;
Sources: