GUI Environment

For more details about the GUI environment, refer to the Eagle Dynamics documentation:

C:\Program Files\Eagle Dynamics\DCS World\API\DCS_ControlAPI.md
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Usage

To use Pelican in the GUI environment, create a Lua script in the following directory:

%USERPROFILE%\Saved Games\DCS\Scripts\Hooks
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This script must include the DLL path in Lua’s package.cpath so it can load the Pelican module.

DCS World will automatically run all Lua scripts in this folder at startup.

Example: Starting a JSON-RPC Server

Create a Lua file named PelicanTestGameGUI.lua with the following content:

-- %USERPROFILE%\Saved Games\DCS\Scripts\Hooks\PelicanTestGameGUI.lua

package.cpath = package.cpath .. ";" .. lfs.writedir() .. "\\Mods\\tech\\Pelican\\bin\\?.dll"
PELICAN = { logger_level = "debug" }

local status, ____pelican = pcall(require, "pelican")
if not status then
    log.write("PELICAN", log.ERROR, "Failed to load Pelican: " .. tostring(____pelican))
    return
else
    log.write("PELICAN", log.INFO, "Pelican loaded successfully")
end

local logger = ____pelican.logger

local my_logger = logger.Logger.new("PELICAN.GUI")

my_logger:info("Pelican Running...")

local jsonrpc = ____pelican.jsonrpc

local server = jsonrpc.JsonRpcServer.new({ host = "127.0.0.1", port = 1234 })
local router = jsonrpc.JsonRpcRouter.new()

router:add_method(
    "ping",
    function(params)
        local param = params[1]
        return { message = "pong " .. param }
    end
)

local user_callbacks = {}

function user_callbacks.onSimulationFrame()
    local result, err = server:process_rpc(router)
    if not result then
        log.error("PELICAN", log.INFO, "RPC error: " .. tostring(err))
    end
end

log.write("PELICAN", log.INFO, "Scheduling user callbacks for simulation frame processing...")
DCS.setUserCallbacks(user_callbacks)
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Testing the Server

To test the RPC server, run this command in the terminal:

curl --location 'http://localhost:1234/rpc' \
--header 'Content-Type: application/json' \
--data '{
  "jsonrpc": "2.0",
  "method": "ping",
  "params": [1],
  "id": "1"
}'
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Expected Response

{
    "jsonrpc": "2.0",
    "id": "1",
    "result": {
        "message": "pong 1"
    }
}
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You can also check the server's health endpoint at:

http://localhost:1234/health
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