Asterisk ARI Integration

Overview

Asterisk ARI (Asterisk REST Interface) allows you to connect IntraCord AI voice agents to your existing Asterisk PBX. ARI provides a WebSocket-based event model for controlling calls via Stasis applications, giving IntraCord full control over call flow and audio streaming.

This guide focuses on the IntraCord-specific configuration. For general Asterisk installation and administration, refer to the official Asterisk documentation.

Prerequisites

Before setting up the ARI integration, ensure you have:

• A running Asterisk instance with chan_websocket and res_websocket_client modules available. Known-working setups: (a) Asterisk 22+, (b) Asterisk 20 LTS with these modules included
• ARI module enabled in Asterisk
• chan_websocket (WebSocket channel driver) and res_websocket_client (loads websocket_client.conf) enabled in your Asterisk build. Verify with asterisk -rx "module show like chan_websocket" and asterisk -rx "module show like res_websocket_client" — both should report Running.
• Network connectivity between your IntraCord instance and Asterisk
• IntraCord AI instance running and accessible

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If you compiled Asterisk from source, ensure both chan_websocket and res_websocket_client are included during the build. These modules are required for external media streaming between Asterisk and IntraCord. Refer to the Asterisk build system documentation for details on enabling modules.

Asterisk Configuration

The following Asterisk configuration files need to be set up to work with IntraCord. These are minimal examples focused on the IntraCord integration -- refer to the Asterisk documentation for full configuration details.

Enable ARI (ari.conf)

Create an ARI user that IntraCord will use to authenticate:

[general]
enabled = yes

[IntraCord]
type = user
read_only = no
password = your_secure_password

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The username (section name, e.g., IntraCord) and password here must match the Stasis App Name and App Password you configure in IntraCord.

Enable the HTTP Server (http.conf)

ARI requires the Asterisk HTTP server to be enabled:

[general]
enabled = yes
bindaddr = 0.0.0.0
bindport = 8088

Configure the Stasis Dialplan (extensions.conf)

Route incoming calls to your Stasis application so IntraCord can handle them:

[from-external]
exten => _X.,1,NoOp(Incoming call to ${EXTEN})
 same => n,Stasis(IntraCord)
 same => n,Hangup()

Replace IntraCord with the app name you configured in ari.conf and in IntraCord.

Configure External Media Streaming (websocket_client.conf)

IntraCord uses Asterisk's external media streaming to send and receive audio over WebSocket. Configure a WebSocket client connection that points to your IntraCord instance:

IntraCord Cloud

[IntraCord]
type = websocket_client
uri = wss://api.IntraCord.com/api/v1/telephony/ws/ari
protocols = media
tls_enabled = yes
ca_list_file = /etc/ssl/certs/ca-certificates.crt

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tls_enabled = yes is required even though the URI scheme is wss:// — without it Asterisk will not negotiate TLS and the connection will fail. The ARI credentials (Stasis App Name and App Password) must match what you configure in the IntraCord dashboard under Telephony Settings.

Self-hosted

[IntraCord]
type = websocket_client
uri = ws://your-IntraCord-host:port/api/v1/telephony/ws/ari
protocols = media

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Self-hosted deployments on an internal network may use an unencrypted WebSocket (ws://). If your IntraCord instance is exposed over HTTPS, use wss:// and the corresponding hostname instead.

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The section name (e.g., IntraCord) is the WebSocket Client Name you'll enter in the IntraCord telephony configuration. This name tells Asterisk which WebSocket connection to use for external media streaming during calls.

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Configure the uri as a base URL only, without a query string. During each call, IntraCord asks Asterisk to create an externalMedia channel and Asterisk appends workflow_id, organization_id, and workflow_run_id through the v() transport data for that call. Opening /api/v1/telephony/ws/ari directly in a browser or with wscat can return HTTP 403 because those routing parameters are missing; that is expected and does not indicate a websocket_client.conf misconfiguration.

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IntraCord's external media channel uses G.711 μ-law (ulaw). Make sure any PJSIP endpoint or SIP trunk that places or receives calls through IntraCord allows ulaw (e.g. allow=ulaw in the endpoint config).

Refer to the Asterisk WebSocket documentation for additional websocket_client.conf options and TLS configuration.

Apply the configuration changes

After editing any of the files above, reload the affected Asterisk modules from the Asterisk CLI (asterisk -rvvv):

ari reload                                 # picks up ari.conf changes
dialplan reload                            # picks up extensions.conf changes
module reload res_websocket_client.so      # picks up websocket_client.conf changes

Changes to http.conf require a full Asterisk reload (core reload) or a service restart.

Configuration in IntraCord

Step 1: Navigate to Telephony Settings

1. Navigate to /telephony-configurations and click Add configuration
2. Select Asterisk ARI as your provider

Step 2: Enter Your ARI Credentials

Configure the following fields:

Field	Description	Example
ARI Endpoint URL	HTTP base URL of your Asterisk ARI server	http://asterisk.example.com:8088
Stasis App Name	The ARI username configured in ari.conf	IntraCord
App Password	The ARI password configured in ari.conf	your_secure_password
WebSocket Client Name	The connection name from websocket_client.conf	IntraCord
From Extensions	Optional SIP extensions or trunk numbers for outbound calls	PJSIP/6001 or 6001

Step 3: Save and Add Extensions

1. Click Save Configuration
2. Open the configuration you just created and add each SIP extension that should be reachable as a phone number (e.g. 8000). For inbound, you'll assign a workflow to each extension separately — see Inbound Calling below.
3. Create a test workflow and initiate a test call to verify the connection.

Inbound Calling

Unlike other telephony providers that use HTTP webhooks for inbound calls, ARI delivers inbound calls as StasisStart events on the ARI WebSocket. IntraCord automatically detects these events and activates the workflow assigned to the called extension.

How It Works

1. An external call arrives at Asterisk and the dialplan routes it to Stasis(IntraCord)
2. Asterisk fires a StasisStart event over the ARI WebSocket with the channel in Ring state and the dialed extension in the dialplan context
3. IntraCord looks up the called extension in your telephony configuration's phone numbers, finds the assigned workflow, validates quota, and creates a workflow run
4. The call is answered, bridged to an external media channel, and your voice agent workflow begins

Workflow assignment is per extension, so different extensions on the same Asterisk can route to different agents.

Setting Up Inbound Calls

Step 1: Configure the Asterisk dialplan

Ensure your dialplan routes the extensions you care about into the Stasis application. Either route a specific extension:

[from-external]
exten => 8000,1,NoOp(Incoming call to 8000)
 same => n,Stasis(IntraCord)
 same => n,Hangup()

…or use a pattern that catches every extension you'll register in IntraCord:

[from-external]
exten => _X.,1,NoOp(Incoming call to ${EXTEN})
 same => n,Stasis(IntraCord)
 same => n,Hangup()

Replace IntraCord with the app name you configured in ari.conf and in IntraCord.

Step 2: Add the extension as a phone number in IntraCord

1. Go to /telephony-configurations and open your Asterisk ARI configuration

2. In the Phone numbers section, add a phone number whose address is the SIP extension (e.g. 8000)

3. Set its Inbound workflow to the agent that should answer

4. Save

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   Adding the extension in IntraCord doesn't change Asterisk's dialplan — that's what Step 1 is for. The IntraCord entry tells the StasisStart handler which workflow to run when a call to that extension reaches the Stasis app.

Repeat Step 2 for each extension that should reach a voice agent.

Step 3: Test an inbound call

Place a call to one of the extensions you configured. You should see the assigned workflow activate and the voice agent respond.

Inbound Call Context

When an inbound call activates a workflow, the following context is available to your workflow:

Field	Description
caller_number	The caller's phone number or extension
called_number	The dialed number or extension
direction	Always inbound
call_id	The Asterisk channel ID
provider	Always ari

Troubleshooting

Cannot connect to ARI endpoint

• Verify the ARI endpoint URL is correct and reachable from your IntraCord instance
• Check that the Asterisk HTTP server is running (http.conf has enabled = yes)
• Ensure firewall rules allow traffic on the ARI port (default: 8088)
• Confirm the ARI module is loaded: run module show like res_ari in the Asterisk CLI

Authentication failed

• Verify the Stasis App Name matches the ARI user section name in ari.conf
• Check the App Password matches the password in ari.conf
• Ensure there are no extra spaces in the credentials

No audio during calls

• Verify chan_websocket is loaded: run module show like chan_websocket in the Asterisk CLI
• Check that websocket_client.conf is correctly configured with the right IntraCord URI
• Ensure the WebSocket Client Name in IntraCord matches the section name in websocket_client.conf
• Verify network connectivity and firewall rules allow WebSocket traffic between Asterisk and IntraCord

Calls not reaching IntraCord

• Ensure the dialplan routes calls to Stasis(your_app_name)
• Verify the app name in the dialplan matches the ARI user in ari.conf
• Check Asterisk CLI for errors: asterisk -rvvv
• Confirm the ARI WebSocket connection is active

Inbound calls are immediately hung up

• Verify the called extension is added as a phone number under your ARI configuration in /telephony-configurations and has an Inbound workflow assigned
• Confirm the workflow exists and belongs to the same organization as the ARI config
• Check that your organization has available quota
• Review IntraCord logs for warnings like "no matching phone number registered for config" or "has no inbound_workflow_id assigned"

WebSocket client connection issues

• Check the URI in websocket_client.conf points to the correct IntraCord host and port
• Verify the IntraCord instance is running and accepting WebSocket connections
• If using TLS, ensure certificates are correctly configured on both sides

Best Practices

• Keep your Asterisk instance on the same network or a low-latency connection to IntraCord for optimal audio quality
• Use strong passwords for ARI authentication
• Restrict ARI access to known IP addresses using firewall rules
• Monitor Asterisk logs alongside IntraCord logs when debugging call issues
• Keep Asterisk updated to the latest stable version for security and compatibility

Further Reading

• Asterisk Documentation -- official reference for all Asterisk configuration
• ARI Documentation -- detailed ARI configuration and API reference