Asterisk

Run assistant-api with Asterisk PBX using AudioSocket (native TCP) or WebSocket transport.

Asterisk integrates with Rapida using two transport methods. Choose based on your Asterisk version and network topology.

Transport Comparison

	AudioSocket	WebSocket
Asterisk version	16+	20+
Module	res_audiosocket	chan_websocket
Protocol	Raw TCP port 4573	WSS (standard HTTPS port)
Firewall	TCP 4573 must be open outbound	Standard HTTPS only
Audio codec	SLIN 16-bit 8kHz	μ-law 8kHz
Latency	Lowest	Slightly higher
TLS	No	Yes (native WSS)
Best for	LAN / private network	Cloud / NAT traversal

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AudioSocket

1. Configure env vars

   # docker/assistant-api/.assistant.env
   PUBLIC_ASSISTANT_HOST=your-hostname.com
   AUDIOSOCKET__HOST=0.0.0.0
   AUDIOSOCKET__PORT=4573
   

   assistant-api binds a TCP AudioSocket server on AUDIOSOCKET__PORT at startup.

2. Verify the module is loaded

   asterisk -rx "module show like audiosocket"
   # Expected: res_audiosocket.so
   

   If not loaded, add to /etc/asterisk/modules.conf:

   [modules]
   load = res_audiosocket.so
   
3. Configure the dialplan

   # /etc/asterisk/extensions.conf
   
   [globals]
   RAPIDA_API_KEY = rpd-xxx-your-api-key
   RAPIDA_HOST    = {PUBLIC_ASSISTANT_HOST}   ; HTTP/webhook host (HTTPS)
   RAPIDA_AS_HOST = {PUBLIC_ASSISTANT_HOST}   ; AudioSocket TCP host
   RAPIDA_PORT    = 4573
   ASSISTANT_ID   = 123456789
   
   [rapida-inbound]
   exten => _X.,1,Answer()
    same => n,Set(CHANNEL(audioreadformat)=slin)
    same => n,Set(CHANNEL(audiowriteformat)=slin)
    ; Phase 1 — register the call and get a contextId
    same => n,Set(CTX=${CURL(https://${RAPIDA_HOST}/v1/talk/asterisk/call/${ASSISTANT_ID}?from=${CALLERID(num)}&x-api-key=${RAPIDA_API_KEY})})
    same => n,GotoIf($["${CTX}" = ""]?error)
    ; Phase 2 — open AudioSocket TCP using contextId as UUID
    same => n,AudioSocket(${CTX},${RAPIDA_AS_HOST}:${RAPIDA_PORT})
    same => n,Hangup()
    same => n(error),Playback(an-error-has-occurred)
    same => n,Hangup()
   

   CHANNEL(audioreadformat)=slin and CHANNEL(audiowriteformat)=slin are required. AudioSocket expects SLIN (signed linear PCM) — without this Asterisk will not convert the audio format.

4. Reload and test

   asterisk -rx "dialplan reload"
   
   # Verify connectivity
   nc -zv {RAPIDA_AS_HOST} 4573    # AudioSocket TCP
   curl -I https://{RAPIDA_HOST}   # HTTPS webhook
   

Outbound via ARI (AudioSocket)

For outbound calls, Rapida uses Asterisk’s ARI to originate the channel. The RAPIDA_CONTEXT_ID channel variable is injected by Rapida ARI automatically:

; /etc/asterisk/extensions.conf
[rapida-outbound]
exten => s,1,Set(CHANNEL(audioreadformat)=slin)
 same => n,Set(CHANNEL(audiowriteformat)=slin)
 ; RAPIDA_CONTEXT_ID is set by Rapida ARI when originating the call
 same => n,AudioSocket(${RAPIDA_CONTEXT_ID},${RAPIDA_AS_HOST}:${RAPIDA_PORT})
 same => n,Hangup()

ARI vault credential keys (store in Rapida vault, provider type Asterisk):

Key	Required	Description
ari_url	Yes	ARI base URL, e.g. http://asterisk.local:8088
ari_user	Yes	ARI username
ari_password	Yes	ARI password
endpoint_technology	No	Channel technology — default PJSIP
trunk	No	SIP trunk name — builds PJSIP/trunk/number

---

WebSocket

1. Configure env vars

   # docker/assistant-api/.assistant.env
   PUBLIC_ASSISTANT_HOST=your-hostname.com
   # No AudioSocket port needed — WebSocket uses standard HTTPS
   
2. Verify the module is loaded

   asterisk -rx "module show like chan_websocket"
   # Expected: chan_websocket.so — requires Asterisk 20+
   

   If not loaded, add to /etc/asterisk/modules.conf:

   [modules]
   load = chan_websocket.so
   
3. Configure the dialplan

   # /etc/asterisk/extensions.conf
   
   [globals]
   RAPIDA_API_KEY = rpd-xxx-your-api-key
   RAPIDA_HOST    = {PUBLIC_ASSISTANT_HOST}
   ASSISTANT_ID   = 123456789
   
   [rapida-inbound-ws]
   exten => _X.,1,Answer()
    ; Phase 1 — register the call and get a contextId
    same => n,Set(CTX=${CURL(https://${RAPIDA_HOST}/v1/talk/asterisk/call/${ASSISTANT_ID}?from=${CALLERID(num)}&x-api-key=${RAPIDA_API_KEY})})
    same => n,GotoIf($["${CTX}" = ""]?error)
    ; Phase 2 — open WSS connection with contextId in the URL path
    same => n,WebSocket(wss://${RAPIDA_HOST}/v1/talk/asterisk/ctx/${CTX}?x-api-key=${RAPIDA_API_KEY})
    same => n,Hangup()
    same => n(error),Playback(an-error-has-occurred)
    same => n,Hangup()
   
4. Reload and test

   asterisk -rx "dialplan reload"
   curl -I https://{RAPIDA_HOST}
   

Outbound via ARI (WebSocket)

; /etc/asterisk/extensions.conf
[rapida-outbound-ws]
exten => s,1,NoOp(Outbound WebSocket call)
 ; RAPIDA_CONTEXT_ID is set by Rapida ARI
 same => n,WebSocket(wss://${RAPIDA_HOST}/v1/talk/asterisk/ctx/${RAPIDA_CONTEXT_ID}?x-api-key=${RAPIDA_API_KEY})
 same => n,Hangup()

Same ARI vault credentials apply — see the AudioSocket section.

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Production URLs

For Rapida SaaS:

Variable	Value
RAPIDA_HOST (HTTP/WebSocket)	websocket-01.in.rapida.ai
RAPIDA_AS_HOST (AudioSocket TCP)	socket-01.in.rapida.ai
RAPIDA_PORT	4573

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SIP

Built-in SIP server for direct SIP connectivity

Configure Your Own

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Configuration

AUDIOSOCKET env vars reference

Telephony Overview

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