Diagram Types

Contents

• Call graph
• Class hierarchy
• Module dependencies
• Containment
• Complexity heatmap
• Attack surface / data flow

---

Call Graph

Shows which functions call which. Built from callers_of / callees_of queries and calls edges.

Mermaid type: flowchart

When to use --focus: Almost always. Without focus, large codebases produce unreadable diagrams. Start with --depth 2 and increase if needed.

Arrow styles reflect edge confidence:

• Solid (-->) = certain (direct call)
• Dashed (-.->) = inferred (attribute access on non-self)
• Dotted (..->) = uncertain (dynamic dispatch)

Example output:

flowchart TB
    query_api_QueryEngine_callers_of["callers_of, method"]
    query_api_QueryEngine_callees_of["callees_of, method"]
    query_api_QueryEngine_paths_between["paths_between, method"]
    storage_graph_store_GraphStore_find_node_id["find_node_id, method"]
    query_api_QueryEngine_callers_of --> storage_graph_store_GraphStore_find_node_id
    query_api_QueryEngine_callees_of --> storage_graph_store_GraphStore_find_node_id
    query_api_QueryEngine_paths_between --> storage_graph_store_GraphStore_find_node_id

Script invocation:

uv run {baseDir}/scripts/diagram.py \\
    --target {targetDir} --type call-graph \\
    --focus QueryEngine --depth 2

---

Class Hierarchy

Shows inheritance (<|--) and interface implementation (<|..) relationships between classes, structs, interfaces, and traits.

Mermaid type: classDiagram

Limitations: Languages without class inheritance (e.g., Go, C) produce empty diagrams. The script emits a note node in that case.

Example output:

classDiagram
    class models_nodes_CodeUnit {
        class
    }
    class models_edges_CodeEdge {
        class
    }
    models_nodes_CodeUnit <|-- models_nodes_Parameter

Script invocation:

uv run {baseDir}/scripts/diagram.py \\
    --target {targetDir} --type class-hierarchy

---

Module Dependencies

Shows import relationships between modules. Built from imports edges.

Mermaid type: flowchart

Best with --direction LR for left-to-right dependency flow.

Example output:

flowchart LR
    query_api["api, module"]
    storage_graph_store["graph_store, module"]
    models_nodes["nodes, module"]
    query_api --> storage_graph_store
    storage_graph_store --> models_nodes

Script invocation:

uv run {baseDir}/scripts/diagram.py \\
    --target {targetDir} --type module-deps --direction LR

---

Containment

Shows classes and their member functions/methods using contains edges.

Mermaid type: classDiagram (with member lists)

Example output:

classDiagram
    class storage_graph_store_GraphStore {
        +callers_of()
        +callees_of()
        +paths_between() list
        +find_node() CodeUnit
    }

Script invocation:

uv run {baseDir}/scripts/diagram.py \\
    --target {targetDir} --type containment

---

Complexity Heatmap

Shows functions color-coded by cyclomatic complexity with call edges between them. Only nodes meeting --threshold are included.

Mermaid type: flowchart with classDef styles

Color scale:

• Green (low): CC < 5
• Yellow (medium): CC 5-10
• Red (high): CC > 10

Example output:

flowchart TB
    parsers_python_parser_parse_file["parse_file, method, CC=15"]:::high
    parsers_python_parser_visit_class["visit_class, method, CC=8"]:::medium
    parsers_python_parser_parse_file --> parsers_python_parser_visit_class
    classDef low fill:rgba(40,167,69,0.2),stroke:#28a745,color:#28a745
    classDef medium fill:rgba(255,193,7,0.2),stroke:#e6a817,color:#e6a817
    classDef high fill:rgba(220,53,69,0.2),stroke:#dc3545,color:#dc3545

Script invocation:

uv run {baseDir}/scripts/diagram.py \\
    --target {targetDir} --type complexity --threshold 5

---

Attack Surface / Data Flow

Shows paths from entrypoints (user input, API endpoints) to sensitive functions. Entrypoints are styled distinctly (rounded rectangles, blue).

Mermaid type: flowchart

Without --focus, the script targets the top 10 complexity hotspots reachable from entrypoints. With --focus, it shows all paths from entrypoints to the specified function.

Example output:

flowchart TB
    handle_request(["handle_request, function"]):::entrypoint
    validate_input["validate_input, function"]
    execute_query["execute_query, function"]
    handle_request --> validate_input
    validate_input --> execute_query
    classDef entrypoint fill:rgba(0,123,255,0.2),stroke:#007bff,color:#007bff

Script invocation:

# Focus on a specific sensitive function
uv run {baseDir}/scripts/diagram.py \\
    --target {targetDir} --type data-flow \\
    --focus execute_query

# Auto-detect: entrypoints to top complexity hotspots
uv run {baseDir}/scripts/diagram.py \\
    --target {targetDir} --type data-flow