Extended Connected JSON Specification

A specification how to interpret various JSON constructs as Connected JSON.

Permanent URL: J-S-O-N.org. The connected JSON.org :)

Version	5.0.0 (SemVer)
Date	2025-07-14
Editor	Dr. Max Völkel
Status	Draft
Spec	this site
Git	https://github.com/Calpano/connected-json.git

Version

5.0.0 (SemVer)

Date

2025-07-14

Editor

Dr. Max Völkel

Status

Draft

Spec

this site

Git

https://github.com/Calpano/connected-json.git

1. Introduction

1.1. Goals and Motivation

Real-world JSON comes in many dialects and variants. This document defines how to interpret various JSON structures unambiguously as a graph of nodes and edges. For clarity, the interpretation as Connected JSON is given. Many formats in the wild are already quite close to Extended CJ anyway. Extended CJ is a superset of JSON Graph Format.

Different from GraphML and Connected JSON, this format allows flexible data attachment directly onto elements alongside the core graph structure: Any element can carry arbitrary additional properties. No intermediate data required.

As this format is meant for relaxed parsing of various CJ-like JSON dialects, it does not define rules for stream processing. See Notes on Streaming JSON and especially Streaming in CJ for details.

1.2. Example

First of all, all Connected JSON files are valid Extended CJ. So look at the example in the CJ specification.

Here is a simple example showcasing some additional features:

Extended CJ Example File

{
  "nodes": [
    // can use a number for an ID
    { "id":  12 },
    { "id":  "a",
      "ports": [ "a1",
                 { "id": "a2",
                   "ports": [ "a2-1", "a2-2" ]
    }]},
    { "id":  "b", "foo": "bar" },
    { "id":  "c" },
    { "id":  "d" },
    { "id":  "e" },
    { "id":  "f" }
  ],
  // Have any JSON just here, not `data` wrapping
  "hello": ["My data","can be","here"],
  "edges": [
    // source & target shortcuts
    { "source": 12, "target": "a"},
    // normal CJ endpoints
    { "endpoints":  [
      { "direction": "in", "node": 12, "port":  "a2-1"},
      { "direction": "out", "node": "a"}
    ]},

    // ports only available in endpoints syntax
    { "endpoints":  [
      { "direction": "in", "node": 12},
      { "direction": "in", "node": "a", "port": "a2-1" },
      { "direction": "out", "node": "d"},
      { "direction": "out", "node": "e"}
    ]},

    // mixed edges only available in endpoints syntax
    { "endpoints":  [
      { "direction": "in", "node": 12},
      { "direction": "in", "node": "a"},
      { "direction": "out", "node": "d"},
      { "direction": "out", "node": "e"},
      { "direction": "undir", "node": "f"}
    ]}
  ]
}

1.3. Change Log

2025-07-14: Version 5.0.0

Split spec into two parts: Connected JSON for writing strict files, where there is always only one option to encode a structure and Extended CJ which is much more liberal and flexible in parsing.
Moved edgeDefault to Extended CJ.

2. Overview

Extended CJ uses the same conceptual model as Connected JSON, but it maps a broader range of JSON structures to the graph model. It is a superset of Connected JSON.

2.1. Conventions

Where a property is just copied over from the Connected JSON specification with the exact same semantics, we use the symbolic → to indicate this, followed by a link to the documentation in the Cj spec, prefixed with CJ:.

2.2. Polymorphism

Extended CJ uses a kind of 'JSON polymorphism': A property allows multiple JSON types to be used. Interpretation of that JSON value depends on the used type.

For example, the property label is in Extended CJ either a JSON string or a JSON object (multilingual like in Connected JSON). Interpretation is defined per property.
Some properties allow for either a JSON object or a JSON array with multiple such objects. Example: graph and graphs. Their interpretation is described below.

2.2.1. Object vs. Array

The interpretation of an object-vs-array property is by creating an implicit array with one member, the stated object.

Extended CJ Input

{
  "graphs": {
    /* graph A */
  }
}

Connected JSON Interpretation

{
  "graphs": [
    {
      /* graph A */
    }
  ]
}

3. Elements

Every element can carry arbitrary JSON properties besides the ones interpreted by this spec. The interplay with the explicit data property is described in Data.

3.1. Document

For the default document structure, see CJ:Document.

Root Object as Graph Object

In Extended CJ, a graph can be stated at the root level, without using a graph property. Using a graph property is additionally allowed, effectively creating subgraphs. If any Graph-level attributes are used, a synthetic root graph is created. The graph-level properties are applied to this synthetic root graph. If subgraphs are created, those properties inherit downwards as usual.

Table 1. Property Table
Property	Type	Description
`baseUri`	`string`(URI)	Optional. Document-level. Documented in CJ:Document.
`connectedJson`	`object`	Optional. Document-level. Documented in CJ Document Metadata.
`compoundNode`	`boolean`	Optional. Graph-level. Documented in Graph.
`edgeDefault`	`string`	Optional. Graph-level. Documented in Graph.
`edges`	`array`(Edge `[]`)	Optional. Graph-level. Documented in CJ:Graph.
`graph`	`object`(Graph)	Optional. Document-level. Can also be used inside graphs. Documented in CJ:Document and CJ:Graph.
`graphs`	`object`(Graph)
`graph`	`array`(Graph `[]`)
`graphs`	`array`(Graph `[]`)
`id`	`string`	Optional. Graph-level. Documented in CJ:Graph. A number is converted to string to be used as ID.
`id`	`number` (integer)
`label`	`object`	Optional. Graph-level. Documented in CJ:Graph.
`label`	`string`	Optional. Graph-level. See Label.
`meta`	`object`(Graph Metadata])	Optional. Graph Metadata].
`nodes`	`array`(Node `[]`)	Optional. Graph-level. Documented in CJ:Graph.

graph and graphs: If both are used, a single array is constructed with the entry of graph first, followed by the entries of graphs. The whole array is then considered the value of graphs.

The pattern of allowing both (a) a single object or (b) an array of a-objects, is used throughout the spec.

3.2. ID

In all places where a CJ:ID can be used, Extended CJ also allows to state the ID using a JSON number. This number is converted at parse-time into the corresponding string. E.g., the number 3 is convered to the string id "3". Floating-point numbers or negative numbers are not allowed.

3.3. Label

Shorthand

A label definition like "label": "Hello, World" has no language information. It is interpreted as { "value": x } with x being the string value. In other words: A CJ:Label without language.

3.4. Graph

For the default graph structure, see Graph in Connected JSON. Extended CJ adds some aliases.

Table 2. Property Table
Property	Type	Description
`compoundNode`	`boolean`	Optional. Default: `false`. If `true`, and a graph directly contains another graph, the subgraph is interpreted as a synthetic compound node, using the graph id and label. The handling of compound nodes is application-specific. See Nested Graph as Compound Node below. This is similar to DOT syntax using `cluster` as a prefix for subgraphs. Having a cluster prefix is like `"compoundNode": true`.
`edgeDefault`	`string`	Optional. Default is `directed`. Defines the default directedness for edges in this graph and all subgraphs. See Edge Direction.
`id`	`string`	→ CJ:Node.`id`: a CJ:ID
`id`	`number` (integer)	Is converted to string and interpreted as a CJ:ID.
`label`	`object`	→ CJ:Node.`label`: A CJ:Label.
`label`	`string`	Optional. See Label.
`meta`	`object`(Graph Metadata])	Optional. Graph Metadata].
`nodes`	`array`(Node `[]`)	0 to n nodes. Default: Empty.
`edges`	`array`(Edge `[]`)	→ CJ:Graph.`edges`: An array of CJ:Edge
`graph`	`object`(Graph)	`graph` allowed as alias for `graphs`
`graph`	`array`(Graph `[]`)	`graph` allowed as alias for `graphs`
`graphs`	`object`(Graph)	Polymorph object and array
`graphs`	`array`(Graph `[]`)	→ CJ:Graph.`graphs`: An array of CJ:Graphs.

3.4.1. Nested Graph as Compound Node

The graph-level compoundNode property can be used on a graph (or document) to force processing as if the subgraph had been nested in a node.

Inheritance

The compoundNode setting is inherited downwards from parent to child graphs, for all kinds of nesting. Child graphs may overwrite a parent setting. In this case, the redefined value is inherited downwards.

Table 3. Example for Nested Graph as Compound Node
Extended CJ Input `{ "graphs": [{ "id": "graph-A", "nodes": [{ "id": "node-A1" }], "graphs": [{ "compoundNode": true, "id": "graph-B", "label": { "en": "Graph B" }, "nodes": [ { "id": "node-B1" }, { "id": "node-B2" } ] }] }] }`	Connected JSON Interpretation `{ "graphs": [{ "id": "graph-A", "nodes": [ { "id": "node-A1" }, { "id": "graph-B", "graphs": [{ "compoundNode": true, "id": "graph-B", "label": { "en": "Graph B" }, "nodes": [ { "id": "node-B1" }, { "id": "node-B2" } ] }] } ] }] }`

Extended CJ Input

{
  "graphs": [{
    "id": "graph-A",
    "nodes": [{ "id": "node-A1" }],
    "graphs": [{
        "compoundNode": true,
        "id": "graph-B",
        "label": {
          "en": "Graph B"
        },
        "nodes": [
          { "id": "node-B1" },
          { "id": "node-B2" }
        ]
    }]
  }]
}

Connected JSON Interpretation

{
  "graphs": [{
    "id": "graph-A",
    "nodes": [
      { "id": "node-A1" },
      { "id": "graph-B",
        "graphs": [{
            "compoundNode": true,
            "id": "graph-B",
            "label": {
              "en": "Graph B"
            },
            "nodes": [
              { "id": "node-B1" },
              { "id": "node-B2" }
            ]
        }]
      }
    ]
  }]
}

3.5. Node

For the default node structure, see Node in Connected JSON.

Table 4. Property Table
Property	Type	Description
`id`	`string`	→ CJ:Node.`id`: a CJ:ID
`id`	`number` (integer)	Is converted to string and interpreted as a CJ:ID.
`label`	`string`	Interpreted as `{ "value": x }` with x being the string value. In other words: A CJ:Label without language.
`ports`	`array`(Port `[]`)	→ CJ:Node.`ports`: an array of CJ:Port
`graphs`	`array` (Graph[])	→ CJ:Node `graphs`: An array of CJ:Graphs.
`graph`	`object`(Graph)	`graph` allowed as alias for `graphs`
`graph`	`array`(Graph `[]`)	`graph` allowed as alias for `graphs`
`graphs`	`object`(Graph)	Polymorph object and array

3.6. Port

For the default port structure, see Port in Connected JSON.

Property Type Description

Property	Type	Description
`id`	`string`	→ CJ:Port.`id`: a CJ:ID
`id`	`number`	See ID
`label`	`object`	→ CJ:Port.`label`: A CJ:Label.
`label`	`string`	See Label
`ports`	`array`(Port `[]`)	→ CJ:Port.`ports`: An array of CJ:Ports.

id

string

→ CJ:Port.id: a CJ:ID

id

number

See ID

label

object

→ CJ:Port.label: A CJ:Label.

label

string

See Label

ports

array(Port [])

→ CJ:Port.ports: An array of CJ:Ports.

3.7. Edge

For the default edge structure, see Edge in Connected JSON.

Property Type Description

Property	Type	Description
`id`	`string`	→ CJ:Edge.`id`: a CJ:ID
`id`	`number`	See ID
`directed`	`boolean`	Default: `true`. See Edge Direction and Graph.`edgeDefault`.
`label`	`object`	→ CJ:Edge.`label`: A CJ:Label.
`label`	`string`	See Label
`type`	`string`	→ CJ:Edge.`type`
`typeUri`	`string`	→ CJ:Edge.`typeUri`
`typeNode`	`string`	→ CJ:Edge.`typeNode`
`typeNode`	`number` (integer)	Interpreted as the ID of the Node that defines the type of edge. Like CJ:Edge.`typeNode`.
Defining Endpoints
`source`	`string`	A single node id interpreted as endpoint with direction `in`. See below.
`source`	`number`	A single node id (converted to string) interpreted as endpoint with direction `in`. See below.
`source`	`array`(node id `[]`)	An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction `in`. See below.
`sources`	`string`	A single node id interpreted as endpoint with direction `in`. See below.
`sources`	`number`	A single node id (converted to string) interpreted as endpoint with direction `in`. See below.
`sources`	`array`(node id `[]`)	An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction `in`. See below.
`target`	`string`	A single node id interpreted as endpoint with direction `out`. See below.
`target`	`number`	A single node id (converted to string) interpreted as endpoint with direction `out`. See below.
`target`	`array`(node id `[]`)	An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction `out`. See below.
`targets`	`string`	A single node id interpreted as endpoint with direction `out`. See below.
`targets`	`number`	A single node id (converted to string) interpreted as endpoint with direction `out`. See below.
`targets`	`array`(node id `[]`)	An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction `out`. See below.
`endpoints`	`array` (Edge Endpoint `[]`)	This is the canonical way to express edges.
Nested Graphs
`graph`	`object` (Graph)	`graph` allowed as alias for `graphs`
`graph`	`array` (Graph `[]`)	`graph` allowed as alias for `graphs`
`graphs`	`object`(Graph)	Polymorph object and array
`graphs`	`array` (Graph `[]`)	→ CJ:Edge `graphs`: An array of CJ:Graphs.

id

string

→ CJ:Edge.id: a CJ:ID

id

number

See ID

directed

boolean

Default: true. See Edge Direction and Graph.edgeDefault.

label

object

→ CJ:Edge.label: A CJ:Label.

label

string

See Label

type

string

→ CJ:Edge.type

typeUri

string

→ CJ:Edge.typeUri

typeNode

string

→ CJ:Edge.typeNode

typeNode

number (integer)

Interpreted as the ID of the Node that defines the type of edge. Like CJ:Edge.typeNode.

Defining Endpoints

source

string

A single node id interpreted as endpoint with direction in. See below.

source

number

A single node id (converted to string) interpreted as endpoint with direction in. See below.

source

array(node id [])

An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction in. See below.

sources

string

A single node id interpreted as endpoint with direction in. See below.

sources

number

A single node id (converted to string) interpreted as endpoint with direction in. See below.

sources

array(node id [])

An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction in. See below.

target

string

A single node id interpreted as endpoint with direction out. See below.

target

number

A single node id (converted to string) interpreted as endpoint with direction out. See below.

target

array(node id [])

An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction out. See below.

targets

string

A single node id interpreted as endpoint with direction out. See below.

targets

number

A single node id (converted to string) interpreted as endpoint with direction out. See below.

targets

array(node id [])

An array containing either strings or integers (converted to strings) interpreted as node id in an endpoint with direction out. See below.

endpoints

array (Edge Endpoint [])

This is the canonical way to express edges.

Nested Graphs

graph

object (Graph)

graph allowed as alias for graphs

graph

array (Graph [])

graph allowed as alias for graphs

graphs

object(Graph)

Polymorph object and array

graphs

array (Graph [])

→ CJ:Edge graphs: An array of CJ:Graphs.

All endpoint-generating properties () are evaluated and generate endpoints.

Source(s)

Shortcut syntax: All created endpoints are interpreted as incoming. I.e. "source": "n17" has the same effect as
"endpoint": { "node":"n17", "direction": "in" }. Ports are only available in endpoints property.

Target(s)

Shortcut syntax: All created endpoints are interpreted as outgoing. I.e.
"target": "n12" has the same effect as
"endpoint": { "node":"n12", "direction": "out" }.

3.7.1. Bi-Edges

Figure 1. Simplified Structure for Bi-Edges, without Ports, without Nested Graphs

A bi-edge always has exactly 2 endpoints. A generic hyperedge can have 0 to n endpoints.

Example: Directed Bi-Edge

{
  "source": "n12",
  "target": "n17"
}

is the same as

{
  "endpoints": [
    { "node": "n12",  "direction": "in"  },
    { "node": "n17",  "direction": "out" }
  ]
}

{
  "source": "n12",
  "target": "n17",
  "directed": true
}

Example: Undirected Bi-Edge

{
  "source": "n12",
  "target": "n17",
  "directed": false
}

is the same as

{
  "endpoints": [
    { "node": "n12",  "direction": "undir" },
    { "node": "n17",  "direction": "undir" }
  ]
}

Example: Directed Hyper-Edge

{
  "source": ["n12","n3","n123"],
  "target": ["n17","n100"]
}

is the same as

{
  "endpoints": [
    { "node": "n12",  "direction": "in"  },
    { "node": "n3",   "direction": "in"  },
    { "node": "n123", "direction": "in"  },
    { "node": "n17",  "direction": "out" },
    { "node": "n100", "direction": "out" }
  ]
}

Example: Undirected Hyper-Edge

{
  "source": ["n12","n3","n123"],
  "target": ["n17","n100"],
  "directed": false
}

is the same as

{
  "endpoints": [
    { "node": "n12",  "direction": "undir" },
    { "node": "n3",   "direction": "undir" },
    { "node": "n123", "direction": "undir" },
    { "node": "n17",  "direction": "undir" },
    { "node": "n100", "direction": "undir" }
  ]
}

3.8. Edge Endpoint

For the default endpoint structure, see Endpoint in Connected JSON.

Property Type Description

Property	Type	Description
`direction`	`string`	→ CJ:Endpoint.`direction`. See also Edge Direction.
`node`	`string`	→ CJ:Endpoint.`node`: A CJ:ID
`node`	`number` (integer)	Required property. Value may be `string` (see above) or `number` (auto-converted to string). Defines the endpoint node: The node to which the endpoint of the edge is attached.
`port`	`string`	→ CJ:Endpoint.`port`
`port`	`number` (integer)	Optional. Interpreted as a CJ:ID to refer to a Port.
`type`	`string`	→ CJ:Endpoint.`type`
`typeUri`	`string`(URI)	→ CJ:Endpoint.`typeUri`
`typeNode`	`string`	→ CJ:Endpoint.`typeNode`
`typeNode`	`number` (integer)	Auto-converted to a string and interpreted like CJ:Endpoint.`typeNode`.

direction

string

→ CJ:Endpoint.direction. See also Edge Direction.

node

string

→ CJ:Endpoint.node: A CJ:ID

node

number (integer)

Required property. Value may be string (see above) or number (auto-converted to string). Defines the endpoint node: The node to which the endpoint of the edge is attached.

port

string

→ CJ:Endpoint.port

port

number (integer)

Optional. Interpreted as a CJ:ID to refer to a Port.

type

string

→ CJ:Endpoint.type

typeUri

string(URI)

→ CJ:Endpoint.typeUri

typeNode

string

→ CJ:Endpoint.typeNode

typeNode

number (integer)

Auto-converted to a string and interpreted like CJ:Endpoint.typeNode.

4. Features

4.1. Data

In Connected JSON, extended data can only be attached to elements via the data property.

In Extended CJ, data handling is much more relaxed: Each element defined in this spec can have arbitrary additional JSON properties — except those defined in this spec. All additional properties are interpreted as data attached to the structural element. Nested JSON is allowed.

Any other properties are copied over as user-data. Values within the data property remain.

Table 5. Moving User-Defined Properties to `data`
Extended CJ Input `{ "id": "node123", "label": "Apple", "model": "MacBook Pro", "data": { "insurance": false } }`	Connected JSON Interpretation `{ "id": "node123", "label": "Apple", "data": { "model": "MacBook Pro", "insurance": false } }`

Edge case: If an object, e.g., a node, is using both a direct JSON property and the same time the same property key within the data object, but with a different value, then both properties are 'shifted outwards'.

Table 6. Edge Case: Conflicting Properties
Extended CJ Input `{ "id": "node123", "label": "Apple", "model": "MacBook Pro", "insurance": true, "data": { "insurance": false, "foo": "bar", "data" : { "insurance": 7 } } }`	Connected JSON Interpretation `{ "id": "node123", "label": "Apple", "data": { "foo": "bar", "insurance": true, "model": "MacBook Pro", "data": { "insurance": false, "data": { "insurance": 7 } } } }`

Extended CJ Input

{
  "id": "node123",
  "label": "Apple",
  "model": "MacBook Pro",
  "insurance": true,
  "data": {
    "insurance": false,
    "foo": "bar",
    "data" : {
      "insurance": 7
    }
  }
}

Connected JSON Interpretation

{
  "id": "node123",
  "label": "Apple",
  "data": {
    "foo": "bar",
    "insurance": true,
    "model": "MacBook Pro",
    "data": {
      "insurance": false,
      "data": {
        "insurance": 7
      }
    }
  }
}

4.2. Edge Direction

The edge direction can be stated in three locations: (1) on the graph, (2) on each edge, and (3) on each endpoint. The precedence is as follows: endpoint > edge > graph.

The Graph property edgeDefault can be used to set a default direction for all edges in the graph. The two valid values are directed and undirected (the default). This has only an effect if neither the edge nor an endpoint override this setting.
An Edge may state a directed property. If set to true, the edge is directed. If set to false, the edge is undirected. How to interpret a hyperedge with, e.g. 4 endpoints as directed? In Extended CJ, the first endpoint is interpreted as in and all others as out.
Each Edge Endpoint can use a direction property to explicitly state its direction. The valid values are in, out, and undir (undirected). This option is the only one supported by Connected JSON.

Table 7. Examples
Input			Result
endpoint `direction`	edge `directed`	graph `edgeDefault`	Result Endpoint Direction
`in`	Ignored, endpoint is stated		`in`
`out`			`out`
`undir`			`undir`
—	`true`	Ignored, edge is stated	`in`/`out` (see above)
—	`false`	Ignored, edge is stated	`undir`
—	—	`directed`	`in`/`out` (see above)
—	—	`undirected`	`undir`

4.3. Alias Properties

Some properties, such as Edge Endpoint dir, are an alias for another property (here: direction).

If both aliases and the original property are stated, alias values are ignored. See exceptions below. And a parser warning is emitted if the values differ.

Exceptions

Arrays: When one is a single-value and the other is an array, the single value is prepended to the array. The resulting merged array is used. If both state arrays, the arrays are merged. First lexicographically sorted aliases, then the original property.

Table 8. Single and Multi-Value Aliases
Extended CJ Graph Input `{ "id": "graph-1", "nodes": [ { "id": "node-123" }, { "id": "node-456" } ], "node": "node-789" }`	Connected JSON Interpretation `{ "id": "graph-1", "nodes": [ { "id": "node-789" }, { "id": "node-123" }, { "id": "node-456" } ] }`

If multiple aliases are defined, but no original property, the lexicographically first such alias is used. And a parser warning is emitted if the values differ.
Endpoints: All endpoint properties generate endpoints of an edge. So source neither is not overwritten by endpoints.

Appendix A: Reserved Property Names

The following property names are used by Connected JSON in certain places.

Property Usage

Property	Usage
`baseUri`	CJ: Graph base URI for RDF interpretation
`description`	Suggested for Node, Edge, Graph, Port, Edge Endpoint description. Will end up in `data`.
`dir`	Alias for Edge `direction`
`directed`	Edge directedness
`Graph directed: true → edgeDefault: directed`
`Graph directed: false → edgeDefault: undirected`
`direction`	CJ: Edge Endpoint direction (in/out/undir)
`edgeDefault`	Graph default edge direction
`edge`	Alias for Edge `edges`
`edges`	CJ: Graph edges
`endpoint`	Alias for Edge `endpoints`
`endpoints`	CJ: Edge endpoints
`from`	Alias for Edge `source`
`graph`	Alias for Graph `graphs`
`graphs`	CJ: Node nested graphs, Edge nested graphs
`hyperedges`	Alias for Edge `edges`. For JSON Graph compatibility.
`id`	CJ: Node id, Edge id, Graph id, Port id
`label`	CJ: Node, Edge, Graph, Port
`language`	CJ: Label
`node`	CJ: Edge Endpoint referenced node id
`Alias for Graph nodes`
`nodes`	CJ: Graph nodes
`port`	CJ: Edge Endpoint referenced port id
`ports`	CJ: Node ports
`source`	Edge
`sources`	Alias for Edge `source`
`target`	Edge
`targets`	Alias for Edge `target`
`to`	Alias for Edge `target`
`type`	CJ: Edge, Edge Endpoint
`typeNode`	CJ: Edge, Edge Endpoint
`typeUri`	CJ: Edge, Edge Endpoint
`value`	CJ: Label

baseUri

CJ: Graph base URI for RDF interpretation

description

Suggested for Node, Edge, Graph, Port, Edge Endpoint description. Will end up in data.

dir

Alias for Edge direction

directed

Edge directedness

Graph directed: true → edgeDefault: directed

Graph directed: false → edgeDefault: undirected

direction

CJ: Edge Endpoint direction (in/out/undir)

edgeDefault

Graph default edge direction

edge

Alias for Edge edges

edges

CJ: Graph edges

endpoint

Alias for Edge endpoints

endpoints

CJ: Edge endpoints

from

Alias for Edge source

graph

Alias for Graph graphs

graphs

CJ: Node nested graphs, Edge nested graphs

hyperedges

Alias for Edge edges. For JSON Graph compatibility.

id

CJ: Node id, Edge id, Graph id, Port id

label

CJ: Node, Edge, Graph, Port

language

CJ: Label

node

CJ: Edge Endpoint referenced node id

Alias for Graph nodes

nodes

CJ: Graph nodes

port

CJ: Edge Endpoint referenced port id

ports

CJ: Node ports

source

Edge

sources

Alias for Edge source

target

Edge

targets

Alias for Edge target

to

Alias for Edge target

type

CJ: Edge, Edge Endpoint

typeNode

CJ: Edge, Edge Endpoint

typeUri

CJ: Edge, Edge Endpoint

value

CJ: Label

Table 9. Values for Endpoint `direction`
Value	Is Aliases For	Usage in
`incoming`	`in`	Endpoint
`none`	`undir`	Endpoint
`outgoing`	`out`	Endpoint
`undirected`	`undir`	Endpoint