https://wiki.secondlife.com/wiki/LSL_http_server

Goals

Create an alternative to the XMLRPC server for communication with LSL scripts initiated from outside Second Life that is easy to use and scalable.

LSL

• llRequestHTTPServerURL()

An asynchronous event with no return data.
This will create a capability on the cap server that maps to an internal simulator url.
An http_event will be triggered with type 'SERVER_URL' and a body of the cap url created.
If a cap already exists for this object, the existing URL will be passed to the http_event
One server/url per prim.
Example public url: https://sim123.agni.lindenlab.com/cap/f23b4b94-012d-44f2-bd0c-16c328321221

• llClearHTTPServerURL()

This will clear or invalidate the cap for this lsl http server.
Calling llRegisterHTTPServer again after this should generate a new cap URL.
Triggers an http_event with success/fail. (or just always with 'success' if it is not possible to fail)

• http_server(string method, list meta, string body)

Event triggered when an URL is hit.

• method is GET/POST/PUT/DELETE
• meta is a list of meta data about the request.
  o Initially this is only REQUESTING_HOST which is the IP of the request. This can be extended later as needed.
• body is the body of the request

• http_event(integer type, string body)

Triggered for specific events relating to the HTTP server

• SERVER_URL: body will be the cap url that maps to this scripts http server
• URL_LOST: no body, triggered whenever a cap is lost or cleared
  o urls will be lost if the object changes regions or the region restarts