In ArangoDB 1.1, this error is expected, because ArangoDB 1.1 does not yet have the graph API at /_api/graph.
It should work with ArangoDB 1.2. The current version of ArangoDB can be retrieved via either
arangod --version
or
curl -X GET http://127.0.0.1:8529/_api/version
(IP address and/or port may need to be adjusted)
If the server reports a version number less than 1.2, then the graph API is not yet available. If the server reports a version number of at least 1.2, then please try accessing the URL via cURL:
curl -X POST --dump - --data '{"vertices":"myVertices","edges":"myEdges","_key":"myGraph"}' http://127.0.0.1:8529/_api/graph
This should return something non-HTTP 501 result, e.g.:
HTTP/1.1 201 Created
server: triagens GmbH High-Performance HTTP Server
connection: Keep-Alive
content-type: application/json; charset=utf-8
content-length: 137
{"graph":{"_id":"_graphs/myGraph","_rev":"12347803","_key":"myGraph","vertices":"myVertices","edges":"myEdges"},"error":false,"code":201}