Automatically open/close AxelChat on OBS start/exit (Windows)

[synthodome]

OBS Lua script when using AxelChat.exe as a browser source widget/dock (Windows)

1. Create .lua file @ \obs-studio\data\obs-plugins\frontend-tools\scripts
2. Paste the following block:

-- OBS Lua Script: Run an EXE on OBS startup and close it on exit
obs = obslua
local pid = nil
local exePath = nil
local pidfile = (os.getenv("TEMP") or ".") .. "\\obs_launched_pid.txt"

function script_load(settings)
    exePath = obs.obs_data_get_string(settings, "exe_path")
end

-- helper: read pid from pidfile if needed
local function read_pidfile()
    local f = io.open(pidfile, "r")
    if not f then return nil end
    local content = f:read("*a")
    f:close()
    if not content then return nil end
    local n = tonumber(content:match("%d+"))
    return n
end

-- helper: write pid to pidfile
local function write_pidfile(n)
    local f = io.open(pidfile, "w")
    if not f then return end
    f:write(tostring(n))
    f:close()
end

-- helper: remove pidfile
local function remove_pidfile()
    os.remove(pidfile)
end

function script_unload()
    -- try to get pid from memory, else from file
    if pid == nil then
        pid = read_pidfile()
    end

    if pid ~= nil then
        obs.script_log(obs.LOG_INFO, "Terminating launched process and its child processes (PID: " .. tostring(pid) .. ").")

        -- Build a PowerShell command that recursively finds children and forcibly stops them.
        local killCommand = [[powershell -NoProfile -NonInteractive -Command " $p = ]] .. tostring(pid) .. [[ ; $k = @(); function GetChildren($id) { Get-CimInstance Win32_Process | Where-Object { $_.ParentProcessId -eq $id } | ForEach-Object { $k += $_.ProcessId; GetChildren $_.ProcessId } }; GetChildren $p; $k += $p; $k | ForEach-Object { Stop-Process -Id $_ -Force -ErrorAction SilentlyContinue } " ]]

        local result = io.popen(killCommand, "r")
        local output = result:read("*a")
        local rc = result:close()
        remove_pidfile()

        if output and output:find("Exception") then
            obs.script_log(obs.LOG_ERROR, "Error terminating process: " .. output)
        else
            obs.script_log(obs.LOG_INFO, "Process termination command executed for PID " .. tostring(pid))
        end
        pid = nil
    end
end

function script_description()
    return "Runs an EXE (except obs32/64.exe) on OBS start and closes it and all child processes on exit. Uses a recursive Stop-Process -Force to ensure termination and stores PID in a temp file for reliability."
end

function script_properties()
    local props = obs.obs_properties_create()
    obs.obs_properties_add_path(
        props,
        "exe_path",
        "Executable to Run",
        obs.OBS_PATH_FILE,
        "*.exe",
        nil
    )
    return props
end

function script_update(settings)
    exePath = obs.obs_data_get_string(settings, "exe_path")

    -- Prevent launching OBS itself
    local lowerpath = string.lower(exePath or "")
    if lowerpath:find("obs64.exe", 1, true) or lowerpath:find("obs32.exe", 1, true) then
        obs.script_log(obs.LOG_ERROR, "Cannot launch OBS from within OBS (loop prevention).")
        exePath = ""
        return
    end

    if exePath ~= nil and exePath ~= "" then
        print("Starting external program: " .. exePath)
        local sanitizedPath = exePath:gsub("'", "''")
        local command = "powershell -NoProfile -NonInteractive -Command \"$p = Start-Process -FilePath '" .. sanitizedPath .. "' -PassThru; $p.Id\""
        local f = io.popen(command)
        local output = f:read("*a")
        output = output:match("^%s*(.-)%s*$")
        local newpid = tonumber(output:match("(%d+)"))
        f:close()

        if newpid then
            pid = newpid
            write_pidfile(pid)
            obs.script_log(obs.LOG_INFO, "Launched external process: " .. tostring(pid))
        else
            obs.script_log(obs.LOG_ERROR, "Failed to obtain PID when launching: " .. tostring(output))
        end
    else
        print("No executable selected. Please set one in the script properties.")
    end
end

3. OBS: Tools -> Scripts -> +
4. Add AxelChat.exe in Executable to Run

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Recently found Autostarter plugin for OBS https://obsproject.com/forum/resources/autostarter.2083/