Cross-Cutting Examples

All source files are available in the examples directory on GitHub.

Type System

Type declarations, attribute group types (Stroke, Text), type extension, named and anonymous invocations, and syntactic sugar.

diagram sequence;

// Attribute group types
type ThinDashed = Stroke[color="slategray", width=1.0, style="dashed"];
type ThickSolid = Stroke[color="steelblue", width=2.5];
type BoldText = Text[font_size=16, color="darkblue", font_family="Arial"];
type SmallText = Text[font_size=11, color="gray"];

// Component types using attribute groups
type Service = Rectangle[fill_color="#e6f3ff", stroke=ThickSolid, text=BoldText];
type Store = Rectangle[fill_color="#e0f0e0", stroke=[color="#339966"], rounded=8, text=[color="#2d6a2d"]];

// Type extension — later attributes override earlier ones
type CriticalService = Service[fill_color="#ffe0e0", stroke=[color="red", width=3.0]];
type ReadReplica = Store[fill_color="#f0f0e0", stroke=ThinDashed];

// Arrow types and extension
type RequestArrow = Arrow[stroke=ThickSolid];
type ResponseArrow = Arrow[stroke=ThinDashed];
type UrgentRequest = RequestArrow[stroke=[color="red"]];

// Construct types
type WarningNote = Note[background_color="#fff3cd", stroke=[color="orange", width=2.0], text=[color="#856404"]];
type CriticalActivation = Activate[fill_color="rgba(255,180,180,0.3)", stroke=[color="red", width=2.0]];
type HighlightFragment = Fragment[background_color="rgba(200,220,255,0.15)", border_stroke=[color="blue", width=2.0]];

// Declarations (`:`) define participants
client as "Browser": Service;
api as "API Gateway": CriticalService;
auth as "Auth Service": Service;
primary_db as "Primary DB": Store;
replica_db as "Read Replica": ReadReplica;

// Sugar syntax — omitting @TypeSpec defaults to @Arrow, @Note, etc.
client -> api: "GET /dashboard";
note [on=[api]]: "Default @Note styling";

// Named invocations (`@`)
api -> @RequestArrow auth: "Validate session";
auth -> @ResponseArrow api: "Session valid";
note @WarningNote [on=[auth]]: "Token expires in 60s";

// Anonymous invocations — one-off types inline
api -> @Arrow[stroke=[color="purple", width=2.0]] primary_db: "SELECT dashboard";

// Named + instance overrides
primary_db -> @ResponseArrow[stroke=[color="green"]] api: "Result set";

// Custom activation and fragment types
api -> @UrgentRequest primary_db: "UPDATE session.last_active";
activate @CriticalActivation primary_db {
    primary_db -> @ResponseArrow api: "Ack";
};

alt @HighlightFragment "replica available" {
    api -> @RequestArrow replica_db: "SELECT analytics (read replica)";
    replica_db -> @ResponseArrow api: "Analytics data";
} else "replica down" {
    api -> @RequestArrow primary_db: "SELECT analytics (fallback)";
    primary_db -> @ResponseArrow api: "Analytics data";
};

api -> @ResponseArrow client: "Dashboard payload";

Source: type_system.orr

Styling

Stroke attributes (color, width, style, dash patterns, line cap/join), text attributes (font size, font family, color, background, padding), color formats (named, hex, rgb, rgba), and styling on components, relations, notes, activations, and fragments.

diagram sequence;

// Stroke types
type SolidStroke = Stroke[color="navy", width=2.0, style="solid"];
type DashedStroke = Stroke[color="crimson", width=1.5, style="dashed"];
type DottedStroke = Stroke[color="gray", width=1.0, style="dotted"];
type CustomDashStroke = Stroke[color="purple", width=2.0, style="5,3,2,3"];
type RoundCapStroke = Stroke[color="teal", width=3.0, cap="round", join="round"];

// Text types
type HeaderText = Text[font_size=18, font_family="Arial", color="darkblue"];
type MonoText = Text[font_size=12, font_family="Courier New", color="#333333"];
type HighlightText = Text[font_size=14, color="darkred", background_color="lightyellow", padding=4.0];

// Component types using stroke and text groups
type Primary = Rectangle[fill_color="#e6f3ff", stroke=SolidStroke, text=HeaderText];
type Secondary = Rectangle[fill_color="#f0f0f0", stroke=DashedStroke, text=MonoText];
type Accent = Rectangle[fill_color="#fff0f5", stroke=RoundCapStroke, text=HighlightText];

// Arrow types
type SolidArrow = Arrow[stroke=SolidStroke];
type DashedArrow = Arrow[stroke=DashedStroke];
type DottedArrow = Arrow[stroke=DottedStroke];
type PatternArrow = Arrow[stroke=CustomDashStroke];

// Color format arrows: named, hex, rgb, rgba
type NamedColor = Arrow[stroke=[color="coral", width=2.0]];
type HexColor = Arrow[stroke=[color="#2e8b57", width=2.0]];
type RgbColor = Arrow[stroke=[color="rgb(100, 149, 237)", width=2.0]];
type RgbaColor = Arrow[stroke=[color="rgba(148, 0, 211, 0.6)", width=2.0]];

client: Primary;
server: Secondary;
store: Accent;

// Styled relations
client -> @SolidArrow server: "Solid stroke";
server -> @DashedArrow store: "Dashed stroke";
store -> @DottedArrow server: "Dotted stroke";
server -> @PatternArrow client: "Custom dash pattern (5,3,2,3)";

// Inline stroke + text on relations
client -> [stroke=[color="darkorange", width=2.5], text=[color="darkorange", font_size=14, font_family="Arial"]] server: "Inline stroke + text";

server -> [stroke=[color="rgb(100, 149, 237)", width=2.0, style="dashed"], text=[color="#4169e1", background_color="white", padding=3.0]] store: "RGB stroke, highlighted label";

// Color formats
client -> @NamedColor server: "Named: coral";
server -> @HexColor store: "Hex: #2e8b57";
store -> @RgbColor server: "RGB: cornflower";
server -> @RgbaColor client: "RGBA: semi-transparent violet";

// Styled note
note @Note[on=[server], background_color="rgba(255, 255, 200, 0.8)", stroke=[color="goldenrod", width=2.0, style="dashed"], text=[font_size=13, color="darkgoldenrod"]]: "Fully styled note: bg, stroke, text";

// Styled activation
activate @Activate[fill_color="rgba(70, 130, 180, 0.15)", stroke=[color="steelblue", width=2.0]] store {
    server -> [stroke=RoundCapStroke, text=HighlightText] store: "Round cap + join, highlighted text";
    store -> @DashedArrow server: "Response";
};

// Styled fragment
opt @Fragment[background_color="rgba(144, 238, 144, 0.1)", border_stroke=[color="seagreen", width=2.0], separator_stroke=[color="gray", style="dotted"], operation_label_text=[font_size=14, color="seagreen"], section_title_text=[font_size=12, color="gray"]] "cache available" {
    server -> [stroke=[color="seagreen"]] store: "Cache lookup";
    store -> @DashedArrow server: "Cache hit";
};

Source: styling.orr

Embedded Diagrams

Sequence diagrams inside component nodes, component diagrams inside component nodes (with different layout engines), and embedded diagrams inside sequence diagram participants.

diagram component;

type Service = Rectangle[fill_color="#e6f3ff", stroke=[color="#336699"], rounded=5];
type Store = Rectangle[fill_color="#e0f0e0", stroke=[color="#339966"], rounded=8];

// Sequence diagram embedded in a component node
auth_service as "Auth Service": Service embed diagram sequence {
    client: Rectangle[fill_color="#fff0e0"];
    validator: Rectangle[fill_color="#e6f3ff"];
    token_store: Rectangle[fill_color="#e0f0e0"];

    client -> [stroke=[color="steelblue"]] validator: "Credentials";

    activate validator {
        validator -> [stroke=[color="steelblue"]] token_store: "Lookup user";
        token_store -> [stroke=[color="seagreen", style="dashed"]] validator: "User record";
        validator -> validator: "Verify hash";
    };

    alt [border_stroke=[color="green"]] "valid" {
        validator -> [stroke=[color="green"]] token_store: "Create session";
        token_store -> [stroke=[color="seagreen", style="dashed"]] validator: "Session ID";
        validator -> [stroke=[color="green"]] client: "JWT token";
    } else "invalid" {
        validator -> [stroke=[color="#cc3333"]] client: "401 Unauthorized";
    };
};

// Component diagram embedded with basic layout
order_service as "Order Service": Service embed diagram component [layout_engine="basic", background_color="#fafafa"] {
    api as "API Layer": Rectangle[fill_color="#e6f3ff", rounded=3];
    validation as "Validation": Rectangle[fill_color="#fff3cd", rounded=3];
    persistence as "Persistence": Rectangle[fill_color="#e0f0e0", rounded=3];
    cache as "Cache": Rectangle[fill_color="#f0e6ff", rounded=3];

    api -> validation: "Validate";
    validation -> persistence: "Store";
    persistence -> cache: "Invalidate";
    api -> cache: "Read-through";
};

// Component diagram embedded with sugiyama layout
analytics as "Analytics Pipeline": Service embed diagram component [layout_engine="sugiyama", background_color="#fafafa"] {
    ingress as "Ingress": Rectangle[fill_color="#fff0e0"];
    parser as "Parser": Rectangle[fill_color="#e6f3ff"];
    enricher as "Enricher": Rectangle[fill_color="#e6f3ff"];
    aggregator as "Aggregator": Rectangle[fill_color="#e0f0e0"];
    sink as "Sink": Rectangle[fill_color="#f0e6ff"];

    ingress -> parser;
    ingress -> enricher;
    parser -> aggregator;
    enricher -> aggregator;
    aggregator -> sink;
};

gateway as "API Gateway": Service;
db as "Primary DB": Store;

gateway -> auth_service: "Authenticate";
gateway -> order_service: "Place order";
gateway -> analytics: "Stream events";
auth_service -> db: "Sessions";
order_service -> db: "Orders";
order_service -> analytics: "Order events";

// Sequence diagram whose participants contain embedded diagrams
outer as "Outer System": Service embed diagram sequence {

    // Participant with an embedded component diagram
    api_node as "API Server": Rectangle embed diagram component [layout_engine="basic", background_color="#f8f8ff"] {
        router as "Router": Rectangle[fill_color="#e6f3ff", rounded=3];
        middleware as "Middleware": Rectangle[fill_color="#fff3cd", rounded=3];
        handler as "Handler": Rectangle[fill_color="#e0f0e0", rounded=3];

        router -> middleware: "Pre-process";
        middleware -> handler: "Dispatch";
    };

    // Participant with an embedded sequence diagram
    payment_node as "Payment Gateway": Rectangle embed diagram sequence {
        charge_svc: Rectangle[fill_color="#fff0e0"];
        fraud_check: Rectangle[fill_color="#fce4ec"];
        ledger: Rectangle[fill_color="#e0f0e0"];

        charge_svc -> [stroke=[color="steelblue"]] fraud_check: "Evaluate risk";
        fraud_check -> [stroke=[color="seagreen", style="dashed"]] charge_svc: "Score";

        charge_svc -> [stroke=[color="steelblue"]] ledger: "Debit";
        activate ledger {
            ledger -> [stroke=[color="seagreen", style="dashed"]] charge_svc: "Confirmation";
        };
    };

    user: Rectangle[fill_color="#fff0e0"];

    user -> [stroke=[color="steelblue"]] api_node: "POST /checkout";

    activate api_node {
        api_node -> [stroke=[color="steelblue"]] payment_node: "Charge $42.00";

        activate payment_node {
            payment_node -> [stroke=[color="seagreen", style="dashed"]] api_node: "tx_id=abc123";
        };

        api_node -> [stroke=[color="seagreen", style="dashed"]] user: "201 Created";
    };
};

gateway -> outer: "Delegate";

Source: embedded_diagrams.orr