For the sake of immediate usabillity, this API is documented in the form of curl commands with example parameters. Our knowledge graphs come as software containers and can be deployed easily whereever you want to run them. As for any REST API, the endpoints can be called very flexibly, be it from a smartphone app, a web frontend, or just from your local system. 

1 Setting up a Knowledge Graph Project
 

1.1 Initialization

curl -i -H "Content-Type: application/json" -X PUT \ -d '{"token": 2604251, "kg_name": "ShowcaseKG", "project_type": "KG_QAKR"|"KG_QAPL", "persistence":"binary", "persist_file":"products_1000.pkl", "data_path": "/home/kguser/data/"}' \ 10.247.70.8:5000/initialize

Initializes a Knowledge Graph project with parameters such as token, name, type, persistence, and data path.
 

1.2 Get Project Definition

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251}' \ 10.247.70.8:5000/kgproject

Returns the current project definition.
 

1.3 Set Data Path

curl -i -H "Content-Type: application/json" -X PUT \ -d '{"token": 2604251, "data_path": "/home/kguser/data/"}' \ 10.247.70.8:5000/kgpath

Sets a new data path for the project.

1.4 Define Logic-Based KG

curl -i -H "Content-Type: application/json" -X PUT \ -d '{"token": 23571113, "ontofile":"showcase_logic2.qlf", "accessfile":"KG_Access_And_Querying.qlf"}' \ 10.247.70.8:5000/deflogic

Additional endpoint for logic-based projects of type KG_QAPL.

2 Navigating the Knowledge Graph

2.1 Label-Based Navigation

2.1.1 Query Labels

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "query": "Do you have a chopping board made of spruce"}' \ 10.247.70.8:5000/querylabels

Labels are simplified domain-specific terms and refer to entities.

2.1.2 Get All Labels

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251}' \ 10.247.70.8:5000/alllabels

Returns a list of all labels in the Knowledge Graph.
 

2.1.3 Get Triples by Labels

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "labels": ["chopping board", "spruce"], "support":1}' \ 10.247.70.8:5000/triplesbylabel

Triples are the basic statements of the Knowledge Graph. This endpoint returns all triples referenced by the given labels.
 

2.1.4 Get Triples by Label Pair

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "pair": ["chopping board", "spruce"]}' \ 10.247.70.8:5000/triplesbypair

The triple must match both labels.
 

2.1.5 Get Objects by Labels

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "labels": ["materials", "lampshade"]}' \ 10.247.70.8:5000/objectsbylabels

Returns all objects referenced by any of the given labels.
 

2.1.6 Get Labels for an Object

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "object":{"object":"clothing", "type":"KGType.Entity"}}' \ 10.247.70.8:5000/labelsforobjects

Returns all labels for a given object.

2.2 Triple-Based Navigation

2.2.1 Get Triples for a List of Objects

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "objects":[{"object":"gardening tools", "type":"KGType.Entity"}], "support":1}' \ 10.247.70.8:5000/triplesbyobjects

The support parameter specifies how many objects from the list must match a triple.

2.2.2 Get Reifications

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "triple":{"subj":{"object": "dragon", "type": "mythical_creature"},"prop": {"object": "quality", "type": "KGType.Property"}, "obj":{"object": "manager", "type": "KGType.Entity"}}, "withTypes":0}' \ 10.247.70.8:5000/reifications

A reification is a statement that refers to another statement. For example, it can indicate where a statement occurs in product records or descriptive texts.
 

2.2.3 Get Statements

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "number":1237, "type":"KGType.Statement"}' \ 10.247.70.8:5000/stmtortext

Returns the typed triple corresponding to the given statement number.

2.2.4 Get Text Pieces

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "number":"t212", "type":"KGType.Text"}' \ 10.247.70.8:5000/stmtortext

Returns the full text segment corresponding to the given number as a string.

2.3 Object-Based Navigation

2.3.1 Navigate from a Subject

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "subj":{"object":"effort", "type":"KGType.Entity"}, "depth":1, "link_names":[]}' \ 10.247.70.8:5000/objectsbysubj

Returns all typed entities in the object role that are reachable from the given subject within the specified depth. Link names can restrict the traversal.

2.3.2 Get Subjects for an Object

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "obj":{"object":"solution", "type":"KGType.Entity"}, "link_name":""}' \ 10.247.70.8:5000/objectsbyobjs

Returns subject entities for the given object.
 

2.3.3 Get Key Object

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "object":{"object":"bread bag", "type":"KGType.Entity"}}' \ 10.247.70.8:5000/keyobjects

A key is the root of a subgraph, such as a product number from which all specifications depend. This endpoint returns all keys for a given object.
 

3 Persistence, Statistics and Printing

3.1 Save Knowledge Graph

curl -i -H "Content-Type: application/json" -X PUT \ -d '{"token": 2604251, "persist_file":"products_1000.pkl"}' \ 10.247.70.8:5000/persistfile

Saves the Knowledge Graph according to the defined persistence.

3.2 Print Knowledge Graph

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251}' \ 10.247.70.8:5000/printkg

Prints the Knowledge Graph as ASCII text and stores it in a container file. The filename is returned.

3.3 Retrieve Print File

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251, "kg_file_name": "/home/kguser/data/ShowcaseKG.txt", "max_length":0, "start_point":0}' \ 10.247.70.8:5000/kgprintfile

Retrieves a print file in full or in parts.

3.4 Get Statistics

curl -i -H "Content-Type: application/json" -X GET \ -d '{"token": 2604251}' \ 10.247.70.8:5000/kgstatistics

Generates a set of descriptive statistics for the Knowledge Graph.