# Retell with Asterisk AGI **URL:** \ **Category:** Support Help\ **Created:** [January 21, 2026, 2:31pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551 "2026-01-21T14:31:39Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![paksaaibaan](https://avatars.discourse-cdn.com/v4/letter/p/ebca7d/32.png) [@paksaaibaan](https://community.retellai.com/u/paksaaibaan)\ **Post date:** [January 21, 2026, 2:31pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/1 "2026-01-21T14:31:39Z")
Hello Retell Team, We are integrating Retell with Asterisk AGI (Phase 2 – Production). **Workspace:** PAK SAIBAAN **Billing:** Pay-As-You-Go (Active) **Agents:** Multi-State (Inbound & Outbound enabled) **Phone Number:** +1 (201) 379-9352 (Telnyx) ### Issue All POST requests to create calls fail with: ```auto HTTP 404 – Cannot POST /v1/create-phone-call ``` and also via `/v2/create-phone-call`. This is confirmed via: - CURL - Asterisk AGI logs - Retell Community forum (multiple reports) ### Request Please **enable PSTN / Phone Calls API at the workspace level** for: - Outbound PSTN calls - AGI / API-initiated calls This is currently **blocking production** , while all other components are verified working. ### Architecture Asterisk → AGI → Retell API Telecom via Telnyx (US primary), Telecard local deferred. Please confirm once PSTN permissions are enabled so we can retest immediately. Regards, PAK SAIBAAN Workspace ---
**Author:** ![support2](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/support2/32/15_2.png) [@support2](https://community.retellai.com/u/support2)\ **Post date:** [January 21, 2026, 2:32pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/2 "2026-01-21T14:32:04Z")
* * * The 404 error you’re encountering is most commonly caused by an improperly configured phone number in your Retell AI account[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22). The endpoint path itself appears correct (`/v2/create-phone-call` is the current endpoint), so the issue is likely with your phone number setup or payload structure[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22). ## Key Points to Verify **Phone Number Configuration** : Your `from_number` (+1 (201) 379-9352) must be properly configured in Retell AI with an `outbound_agent_id`, or you need to use the `override_agent_id` parameter in your request[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22). **Correct Payload Structure** : Ensure you’re using the correct parameter names[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22): ```typescript import Retell from 'retell-sdk'; const client = new Retell({ apiKey: 'YOUR_RETELL_API_KEY', }); const phoneCallResponse = await client.call.createPhoneCall({ from_number: '+14157774444', to_number: '+12137774445', }); console.log(phoneCallResponse.agent_id); ``` [(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22) Use `override_agent_id` instead of `agent_id`, and `retell_llm_dynamic_variables` instead of `custom_data`[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22): ```json { "from_number": "+16504144521", "to_number": "your_target_number", "override_agent_id": "agent_71724df7636716ceb3a7e244c8", "retell_llm_dynamic_variables": { "name": "Sarah" } } ``` [(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22) ## Phone Number Setup If your Telnyx number isn’t properly imported into Retell AI, you’ll need to configure it[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22). To update an existing phone number for outbound calls[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22): ```typescript const phoneNumberResponse = await client.phoneNumber.update('+14157774444', { inbound_agent_id: 'oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD', nickname: 'Frontdesk Number', ``` [(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22) Verify that your phone number has been purchased/imported and configured through Retell AI—you cannot use arbitrary numbers for the `from_number` parameter[(1)](https://retell.discourse.group/t/404-error-on-create-a-phone-call/22). For further assistance with workspace-level permissions or Telnyx integration specifics, visit [Contact Sales](https://retellai.octolane.com/), ask questions on [Discord](https://discord.com/invite/wxtjkjj2zp), or visit [https://github.com/RetellAI/](https://github.com/RetellAI/). ---
**Author:** ![Omar\_Ashraf](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/omar_ashraf/32/102_2.png) [@Omar\_Ashraf](https://community.retellai.com/u/Omar_Ashraf)\ **Post date:** [January 21, 2026, 5:00pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/3 "2026-01-21T17:00:48Z")
Hello @paksaaibaan Please share the request you are making that gives you 404 and share your org id ---
**Author:** ![paksaaibaan](https://avatars.discourse-cdn.com/v4/letter/p/ebca7d/32.png) [@paksaaibaan](https://community.retellai.com/u/paksaaibaan)\ **Post date:** [January 21, 2026, 6:11pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/5 "2026-01-21T18:11:51Z")
org\_ht8FyON99nTaQfQ0 ---
**Author:** ![support2](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/support2/32/15_2.png) [@support2](https://community.retellai.com/u/support2)\ **Post date:** [January 21, 2026, 6:12pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/6 "2026-01-21T18:12:12Z")
The workspace ID `org_ht8FyON99nTaQfQ0` appears to be a Retell AI workspace identifier.[(1)](https://docs.retellai.com/accounts/workspace) You can find your workspace ID in your workspace settings page.[(1)](https://docs.retellai.com/accounts/workspace) To access it: 1. Navigate to the system settings page and access your workspace settings[(1)](https://docs.retellai.com/accounts/workspace) 2. Retrieve the workspace id from the settings interface[(1)](https://docs.retellai.com/accounts/workspace) The workspace ID (also referred to as org ID) is sometimes requested when debugging issues related to your account.[(1)](https://docs.retellai.com/accounts/workspace) ---
**Author:** ![paksaaibaan](https://avatars.discourse-cdn.com/v4/letter/p/ebca7d/32.png) [@paksaaibaan](https://community.retellai.com/u/paksaaibaan)\ **Post date:** [January 21, 2026, 6:16pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/7 "2026-01-21T18:16:48Z")
Hello, Yes, that is correct. The workspace ID (organization ID) for our account is: org\_ht8FyON99nTaQfQ0 It was retrieved from System Settings → Workspace Settings. Please let me know if you also need the specific request or endpoint that is returning the 404 error. Thanks. ---
**Author:** ![paksaaibaan](https://avatars.discourse-cdn.com/v4/letter/p/ebca7d/32.png) [@paksaaibaan](https://community.retellai.com/u/paksaaibaan)\ **Post date:** [January 21, 2026, 6:22pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/8 "2026-01-21T18:22:44Z")
Hello Team, Thank you for your response. Below are the details you requested regarding the 404 error we are receiving from Retell during live call execution. **Environment** - Platform: Asterisk 20 (Ubuntu) - Integration Method: AGI (Python) - Call Source: SIP trunk (Telecard IP-based inbound) - AGI Script: retell\_agi.py (executed successfully) **Organization ID** - Org ID: **{{org\_ht8FyON99nTaQfQ0}}** **Request Being Made** The AGI script is making the following HTTP request to Retell when a live call is received: - Method: POST - URL: **{{PASTE\_EXACT\_RETELL\_API\_ENDPOINT\_HERE}}** - Headers: - Agent ID Used: **Observed Behavior** - The AGI script executes correctly. - The HTTP request is sent during an active inbound call. - Retell responds with **HTTP 404 (HTML response)**. - The call then exits AGI and hangs up cleanly on Asterisk. **Request** Kindly confirm: 1. Whether the endpoint URL being used is correct for live call handling. 2. Whether this agent ID is valid and active for our organization. 3. If any additional parameters or a different endpoint is required for SIP / Asterisk AGI integrations. We are happy to share sanitized request payloads or logs if required. Looking forward to your guidance. Best regards, **paksaaibaan** ---
**Author:** ![paksaaibaan](https://avatars.discourse-cdn.com/v4/letter/p/ebca7d/32.png) [@paksaaibaan](https://community.retellai.com/u/paksaaibaan)\ **Post date:** [January 22, 2026, 8:03am UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/10 "2026-01-22T08:03:37Z")
Hello Retell Team, We are actively deploying a hybrid PSTN architecture using Telecard (local DID) and Asterisk. Our current blocker is that inbound and outbound PSTN calls are not functioning because the Phone Calls / PSTN API does not appear to be enabled at the workspace level. We confirm: - Correct endpoint in use: `/v2/create-phone-call` - API key is valid - Agent is active - Telecard & Telnyx numbers are available and routable - Asterisk SIP and dialplan are stable Request: Please enable **PSTN / Phone Calls API (Call Sessions)** for our workspace so that: 1. Inbound calls from Telecard via Asterisk can reach the Retell agent 2. Outbound calls can use our local Telecard number as caller ID Workspace: PAK SAAIBAAN Plan: Pay-As-You-Go (ready to upgrade if required) We are blocked only due to this enablement. Best regards, paksaaibaan ---
**Author:** ![Omar\_Ashraf](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/omar_ashraf/32/102_2.png) [@Omar\_Ashraf](https://community.retellai.com/u/Omar_Ashraf)\ **Post date:** [January 22, 2026, 3:47pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/11 "2026-01-22T15:47:19Z")
Hello @paksaaibaan I need the exact request that is returning 404 for you, and also remove your API key from the response. This is a public channel. ---
**Author:** ![paksaaibaan](https://avatars.discourse-cdn.com/v4/letter/p/ebca7d/32.png) [@paksaaibaan](https://community.retellai.com/u/paksaaibaan)\ **Post date:** [January 22, 2026, 6:36pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/13 "2026-01-22T18:36:46Z")
Hello Team, Thank you for the response. I’d like to clarify and correct one point and share updated findings after reviewing the call logs. ---
**Author:** ![paksaaibaan](https://avatars.discourse-cdn.com/v4/letter/p/ebca7d/32.png) [@paksaaibaan](https://community.retellai.com/u/paksaaibaan)\ **Post date:** [January 22, 2026, 6:37pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/14 "2026-01-22T18:37:16Z")
Hello Team, Thank you for the response. I’d like to clarify and correct one point and share updated findings after reviewing the call logs. * * * ### ![🔄](https://canada1.discourse-cdn.com/flex008/uploads/retell1/original/1X/93d3278f03c13ae7ede83207b6f224eb040084e8.png) Correction We have tested outbound calls to **multiple different international numbers** (US and other regions as well), and the issue is **not limited to a single country**. * * * ### ![📞](https://canada1.discourse-cdn.com/flex008/uploads/retell1/original/1X/da00f4060862a709cf9baee55e4c0b6852672411.png) Observed Behavior (From Call History) From the Retell dashboard **Call History** : - Outbound calls are being **initiated successfully** - Calls appear with: - No successful outbound call has connected to the destination number so far Inbound calls, however, are working correctly and reach the assigned agent without issue. * * * ### ![🧪](https://canada1.discourse-cdn.com/flex008/uploads/retell1/original/1X/5f7b3acf3e4bf6209b1f55c3d7aa1f871fef9321.png) Example API Test Used (Key Removed) ```auto curl -i https://api.retellai.com/v2/create-phone-call \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "from_number": "+12013799352", "to_number": "+1XXXXXXXXXX" }' ``` The request is accepted and logged, but the call does not connect successfully. * * * ### ![🔍](https://canada1.discourse-cdn.com/flex008/uploads/retell1/original/1X/83a848f047efd29b880999e39b3cd5c306dee4a3.png) Workspace & Number Configuration - Workspace: **PAK SAAIBAAN** - Plan: **Pay As You Go** - Phone Number: `+1 (201) 379-9352` (Telnyx – visible in Retell dashboard) - Inbound Call Agent: Assigned - Outbound Call Agent: Assigned - Allowed Outbound Countries: **All countries allowed** Despite this, outbound calls consistently fail to connect. * * * ### ![❓](https://canada1.discourse-cdn.com/flex008/uploads/retell1/original/1X/3009d34af2ae80e3cd3f9c84e29f957ce58dff18.png) Clarification Needed Could you please confirm: 1. Whether outbound calling is **fully enabled** for Pay-As-You-Go workspaces using Telnyx-backed numbers. 2. If any **additional enablement, verification, or plan upgrade** is required for outbound PSTN calls to connect. 3. Whether the “dial no answer / not connected” outcome indicates a provider-level block or a workspace-level restriction. * * * Inbound calling is stable on our side; outbound connectivity is the only remaining blocker before we proceed further. Looking forward to your guidance. Best regards, **paksaaibaan** ---
**Author:** ![home.tore](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/home.tore/32/1626_2.png) [@home.tore](https://community.retellai.com/u/home.tore)\ **Post date:** [April 21, 2026, 6:50pm UTC](https://community.retellai.com/t/retell-with-asterisk-agi/551/15 "2026-04-21T18:50:27Z")
I wanted to share a working example of integrating Asterisk with Retell AI using **AGI + PJSIP + register-phone-call** for inbound PSTN calls. This took some trial and error, so hopefully this saves someone else time. ## Final Working Call Flow ```auto Carrier DID (BulkVS / Telnyx / etc) → Asterisk inbound trunk → Dialplan matches AI DID → AGI script calls Retell register-phone-call API → Retell returns call_id → Asterisk dials dynamic SIP URI → Retell agent answers ``` ## Important Discovery For **PJSIP dynamic SIP URI dialing** , the correct syntax is: ```auto PJSIP//sip:user@domain ``` This matches official Asterisk community guidance. ([Asterisk Community](https://community.asterisk.org/t/how-to-dial-dynamic-sip-uri-with-pjsip-in-asterisk-retell-ai-integration/108031?utm_source=chatgpt.com "How to Dial Dynamic SIP URI with PJSIP in Asterisk (Retell ...")) So in this use case: ```auto Dial(PJSIP/retell-direct/sip:${RETELL_CALL_ID}@sip.retellai.com,60) ``` That was the breakthrough. * * * # Example `pjsip.conf` ```auto [transport-tcp] type=transport protocol=tcp bind=0.0.0.0:5060 [retell-direct] type=endpoint transport=transport-tcp disallow=all allow=ulaw aors=retell-direct direct_media=no rewrite_contact=yes rtp_symmetric=yes force_rport=yes from_domain=sip.retellai.com outbound_proxy=sip:sip.retellai.com\;lr [retell-direct] type=aor max_contacts=1 contact=sip:sip.retellai.com:5060 qualify_frequency=60 ``` * * * # Example `extensions.conf` ```auto [from-carrier] exten => +1XXXXXXXXXX,1,NoOp(Inbound call to Retell AI DID) same => n,Set(CALLER_E164=${IF($["${CALLERID(num):0:1}" = "+"]?${CALLERID(num)}:+1${CALLERID(num)})}) same => n,Set(DID_E164=+1XXXXXXXXXX) same => n,AGI(retell_register.py,${CALLER_E164},${DID_E164}) same => n,NoOp(RETELL_CALL_ID=${RETELL_CALL_ID}) same => n,NoOp(RETELL_ERROR=${RETELL_ERROR}) same => n,GotoIf($["${RETELL_CALL_ID}"=""]?fail) same => n,Dial(PJSIP/retell-direct/sip:${RETELL_CALL_ID}@sip.retellai.com,60) same => n,Hangup() same => n(fail),NoOp(Retell registration failed: ${RETELL_ERROR}) same => n,Playback(sorry-cant-let-you-do-that) same => n,Hangup() ``` * * * # Example AGI Script (`retell_register.py`) ```auto #!/usr/bin/env python3 import sys import json import urllib.request import urllib.error RETELL_API_KEY = "rtk_xxxxxxxxxxxxxxxxx" RETELL_AGENT_ID = "agent_xxxxxxxxxxxxx" def read_agi(): while True: line = sys.stdin.readline().strip() if line == "": break def agi_cmd(cmd): sys.stdout.write(cmd + "\n") sys.stdout.flush() return sys.stdin.readline() def setvar(k,v): safe = str(v).replace('"','\\"') agi_cmd(f'SET VARIABLE {k} "{safe}"') def main(): read_agi() from_number = sys.argv[1] to_number = sys.argv[2] payload = { "agent_id": RETELL_AGENT_ID, "from_number": from_number, "to_number": to_number, "direction": "inbound" } req = urllib.request.Request( "https://api.retellai.com/v2/register-phone-call", data=json.dumps(payload).encode(), headers={ "Authorization": f"Bearer {RETELL_API_KEY}", "Content-Type": "application/json" }, method="POST" ) try: with urllib.request.urlopen(req, timeout=10) as r: data = json.loads(r.read().decode()) setvar("RETELL_CALL_ID", data["call_id"]) setvar("RETELL_ERROR", "") except Exception as e: setvar("RETELL_CALL_ID", "") setvar("RETELL_ERROR", str(e)) if __name__ == " __main__": main() ``` Make executable: ```auto chmod +x /var/lib/asterisk/agi-bin/retell_register.py ``` * * * # Notes ## 1. Use REST API Key Use the **Retell REST API key** , not webhook key. ## 2. Agent ID != Phone Number Use: ```auto agent_xxxxxxxxx ``` not the imported DID number. ## 3. DNS Check Make sure your server resolves: ```auto getent hosts sip.retellai.com ``` ## 4. Firewall Allow outbound SIP/RTP traffic. ## 5. Codec I used: ```auto allow=ulaw ``` * * * # Final Result Inbound PSTN calls now route: ```auto Carrier DID → Asterisk → Retell AI agent ``` with full control of routing in Asterisk. This lets you do: - route only specific DIDs to AI - time-of-day routing - failover to queues/extensions - blend human + AI call flows - use your own carriers Hope this helps someone. Thanks to the Asterisk community thread that clarified the correct PJSIP URI format. ([Asterisk Community](https://community.asterisk.org/t/how-to-dial-dynamic-sip-uri-with-pjsip-in-asterisk-retell-ai-integration/108031?utm_source=chatgpt.com "How to Dial Dynamic SIP URI with PJSIP in Asterisk (Retell ..."))