FreePBX Feature code prefix to allow spy/whisper/barge on the specified extension

Targeted ChanSpy

;  FreePBX Feature code prefix to allow spy/whisper/barge on
;  the specified extension. 
; 
; Latest version:
;      https://gist.github.com/lgaetz/78c4e114952e79596c1ed4123559d3d3
;
; Usage: 
;   Dialplan goes in the file:
;      /etc/asterisk/extensions_custom.conf 
;   Dial local extension with 556 prefix to spy. While spying on 
;   active channel use the following dtmf input to toggle modes:
;         dtmf 4 - spy mode
;              5 - whisper mode 
;              6 - barge mode
;
; License:  GNU GPL2
;
; Version History
;      2018-11-23 First commit by lgaetz
;      2019-03-05 update regex to prevent channels from returning multiple channel matches
;      2019-10-10 added support to loop thru all dialable devices for the extension, now supports Zulu/webrtc clients
;      2020-04-12 COVID-19 edition - supports prompt to request spyee extension
;      2020-07-23 add E option to ChanSpy application and add timeout
;      2021-03-08 add example line to block spying access to certain extensions


[from-internal-custom]
exten => 556,1,Noop(Entering user defined context from-internal-custom in extensions_custom.conf)
exten => 556,n,Read(spyee,please-enter-the&extension&number&followed_pound)
exten => 556,n,GoTo(targeted-chanspy,${spyee},1)
exten => _556.,1,Noop(Entering user defined context from-internal-custom in extensions_custom.conf)
exten => _556.,n,GoTo(targeted-chanspy,${EXTEN:3},1)      ;strip off prefix 

[targeted-chanspy]
exten => _.,1,Noop(Entering user defined context targeted-chanspy in extensions_custom.conf)
; exten => _.,n,ExecIF($["${EXTEN}"="100"]?Hangup)  ; if you want to block spying access to certain extensions you can do that with this line, one per ext
exten => _.,n,Set(TIMEOUT(absolute)=3600)   ; prevent hung channel by setting 1 hour timeout recommended if using infinite loop
exten => _.,n,Answer
exten => _.,n(once-upon-a-time),Wait(1)
exten => _.,n,set(spy_target=)   ; initialize target var
; get list of dialable devices for extension
exten => _.,n,Set(DEVS=${DB(AMPUSER/${EXTEN}/device)})   ;  & delimited list of devices
exten => _.,n,Set(DEVS=${STRREPLACE(DEVS,&,\,)})           ;  comma delimited list of devices
; step thru each device and look for an active channel
exten => _.,n,While($["${SET(DEV=${POP(DEVS)})}" != ""])
exten => _.,n,noop(dev: ${DEV})
; using a regex of SIP/${EXTEN}- will match both SIP and PJSIP channels, and the trailing - character should
; help to ensure there is only a single match. If multiple channels are returned the chanspy application will fail
exten => _.,n,set(spy_target=${CHANNELS(SIP/${DEV}-)})  
exten => _.,n,ExecIf($["${spy_target}"!=""]?ExitWhile)  ; if an active channel is found exit the loop
exten => _.,n,EndWhile()
exten => _.,n,ExecIF($["${spy_target}"!=""]?ChanSpy(${spy_target},dnqE))    ; q option suppresses channel announce on barge

exten => _.,n,Hangup()      ;comment this line with a semicolon to do infinite loop
exten => _.,n,GoTo(once-upon-a-time)
exten => _.,n,Hangup()
exten => h,1,Hangup()
exten => s,1,Hangup()
exten => T,1,Hangup()   ; timeout destination

Probably not. If you need detailed help drop by the TangoPBX forum and share your dialplan
https://community.tangopbx.org/