How to Retrieve content by their document library path

You can retrieve content by their document library path using the CMS API using the Node API. For example, you can paginate through the children of a node using this call:

https://api.cloudcms.com/docs#!/node/get_repositories_repositoryId_branches_branchId_nodes_nodeId_children
GET /repositories/{repositoryId}/branches/{branchId}/nodes/{nodeId}/children?path={path}

In this case, you would set "nodeId" to the value "root" to indicate the root node. And then use "path" to describe the offset.
If you wanted the children at "/a/b/c", you would do:

GET /repositories/{repositoryId}/branches/{branchId}/nodes/root/children?path=/a/b/c

Similarly, you can list and query the "relatives" of a node. This is a bit more advanced as it lets you find associated nodes that aren't necessarily children but may be related by any association type:

https://api.cloudcms.com/docs#!/node/post_repositories_repositoryId_branches_branchId_nodes_nodeId_relatives_query
POST /repositories/{repositoryId}/branches/{branchId}/nodes/{nodeId}/relatives/query?direction={direction}&type={type}&path={path}

Suppose you wanted to find all children of a node at path "/a/b/c" where the property "category" = "blue", you could do:

POST /repositories/{repositoryId}/branches/{branchId}/nodes/root/relatives/query?&direction=OUTGOING&type=a:child&path=/a/b/c
{ "category": "blue" }

In this way, you can also find relatives who are INCOMING (such as parents) or use your own association types to find relatives that are one hop away.

There is also a Tree API which provides much of this functionality and may be useful given some of the other things it exposes (specification of depth, child expansion, etc).

The documentation is here:
https://gitana.io/documentation/api/content-services/tree