Building data platform with external twin synchronization

1. A building system of a building comprising one or more memory devices having instructions thereon, that, when executed by one or more processors, cause the one or more processors to:

store a digital twin of the building comprising a graph data structure, the graph data structure comprising a plurality of nodes representing entities of the building and a plurality of edges between the plurality of nodes representing relationships between the entities of the building;

receive a modification to the digital twin of the building, the modification modifying at least one of the plurality of nodes or the plurality of edges;

generate a change feed event of a change feed, the change feed event recording the modification to the graph data structure, the change feed comprising a plurality of change feed events representing modifications to the graph data structure at a plurality of different times;

generate an update for an external digital twin stored by an external system based on the change feed event, the update indicating a change to the external digital twin; and

synchronize, based on the update, the external digital twin of the building of the external system with the digital twin of the building by communicating with the external system.

2. The building system of claim 1 , wherein the entities of the building are at least one of building equipment, locations of the building, users of the building, and events of the building.

3. The building system of claim 1 , wherein the instructions cause the one or more processors to receive the modification to the digital twin of the building by:

receiving an event from a piece of building equipment of the building; and

determining, based on the event, the modification to the digital twin of the building.

4. The building system of claim 1 , wherein the external system updates the external digital twin of the building based on the update.

5. The building system of claim 1 , wherein the instructions cause the one or more processors to:

receive the modification to the digital twin of the building from a second external system, wherein the modification to the digital twin of the building is based on a second modification made by the second external system to a second external digital twin of the building stored by the second external system.

6. The building system of claim 1 , wherein the modification is at least one of:

adding a new node to the plurality of nodes of the graph data structure;

adding a new edge to the plurality of edges of the graph data structure;

deleting an existing node of the plurality of nodes of the graph data structure;

deleting an existing edge of the plurality of edges of the graph data structure;

modifying the existing node of the plurality of nodes of the graph data structure; or

modifying the existing edge of the plurality of edges of the graph data structure.

7. The building system of claim 1 , wherein the instructions cause the one or more processors to:

add the change feed event to a change feed topic, wherein the external system is subscribed to the change feed topic and receives the change feed event in response to the change feed event being added to the change feed topic.

8. The building system of claim 1 , wherein the external digital twin of the building is in a first format different than a format of the digital twin of the building.

9. The building system of claim 8 , where the instructions cause the one or more processors to:

synchronize, based on the change feed event, a second external digital twin of a second external system, the second external digital twin in a second format different than the first format of the external digital twin and the format of the digital twin of the building.

10. The building system of claim 9 , wherein the instructions cause the one or more processors to:

generate a second update for the second external digital twin of the building in the second format for the second external digital twin of the building of the second external system based on the change feed event; and

communicate the second update for the second external digital twin of the building to the second external system, wherein the second external system updates the external digital twin of the building based on the second update.

11. A method comprising:

storing, by a processing circuit, a digital twin of a building comprising a graph data structure, the graph data structure comprising a plurality of nodes representing entities of the building and a plurality of edges between the plurality of nodes representing relationships between the entities of the building;

receiving, by the processing circuit, a modification to the digital twin of the building, the modification modifying at least one of the plurality of nodes or the plurality of edges;

generating, by the processing circuit, a change feed event of a change feed, the change feed event recording the modification to the graph data structure, the change feed comprising a plurality of change feed events representing modifications to the graph data structure at a plurality of different times;

generating, by the processing circuit, an update for an external digital twin stored by an external system based on the change feed event, the update indicating a change to the external digital twin; and

synchronizing, by the processing circuit, based on the update, the external digital twin of the building of the external system with the digital twin of the building by communicating with the external system.

12. The method of claim 11 , wherein the entities of the building are at least one of building equipment, locations of the building, users of the building, and events of the building.

13. The method of claim 11 , wherein receiving, by the processing circuit, the modification to the digital twin of the building comprises:

receiving an event from a piece of building equipment of the building; and

determining, based on the event, the modification to the digital twin of the building.

14. The method of claim 11 , wherein the external system updates the external digital twin of the building based on the update.

15. The method of claim 11 , further comprising:

receiving, by the processing circuit, the modification to the digital twin of the building from a second external system, wherein the modification to the digital twin of the building is based on a second modification made by the second external system to a second external digital twin of the building stored by the second external system.

16. The method of claim 11 , wherein the modification is at least one of:

adding a new node to the plurality of nodes of the graph data structure;

adding a new edge to the plurality of edges of the graph data structure;

deleting an existing node of the plurality of nodes of the graph data structure;

deleting an existing edge of the plurality of edges of the graph data structure;

modifying the existing node of the plurality of nodes of the graph data structure; or

modifying the existing edge of the plurality of edges of the graph data structure.

17. The method of claim 11 , further comprising:

adding, by the processing circuit, the change feed event to a change feed topic, wherein the external system is subscribed to the change feed topic and receives the change feed event in response to the change feed event being added to the change feed topic.

18. The method of claim 11 , wherein the external digital twin of the building is in a first format different than a format of the digital twin of the building.

19. The method of claim 18 , further comprising:

synchronizing, by the processing circuit, based on the change feed event, a second external digital twin of a second external system, the second external digital twin in a second format different than the first format of the external digital twin and the format of the digital twin of the building.

20. One or more memory devices having instructions thereon, that, when executed by one or more processors, cause the one or more processors to:

store a digital twin of a building comprising a graph data structure, the graph data structure comprising a plurality of nodes representing entities of the building and a plurality of edges between the plurality of nodes representing relationships between the entities of the building;

receive a modification to the digital twin of the building, the modification modifying at least one of the plurality of nodes or the plurality of edges;

generate a change feed event of a change feed, the change feed event recording the modification to the graph data structure, the change feed comprising a plurality of change feed events representing modifications to the graph data structure at a plurality of different times;

generate an update for an external digital twin stored by an external system based on the change feed event, the update indicating a change to the external digital twin; and

synchronize, based on the update, the external digital twin of the building of the external system with the digital twin of the building by communicating with the external system.