Exotel SIP Trunking APIs

Connect your PBX, Contact Center, or Voice AI system to the telephone network.

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Quick Start

1. Get Your Credentials

SignUp: https://my.in.exotel.com/auth/register

Complete KYC as per compliance: https://docs.exotel.com/business-phone-system/kyc-verification

Exotel Dashboard → API Credentials:https://my.in.exotel.com/apisettings/site#api-credentials

Purchase Exophone: https://my.in.exotel.com/numbers

Reference docs: https://docs.exotel.com/dynamic-sip-trunking

https://developer.exotel.com/api/sip-trunking-apis

• API Key (username)
• API Token (password)
• Account SID

2. Choose Your Use Case

Use Case	Description	Setup Steps
PSTN (Standard)	Make & receive calls via telephone network	Create Trunk → Map Phone Number → Map ACL → Map Destination URI
StreamKit (Voice AI)	Connect to Voice AI bots	Create Trunk → Map Phone Number (mode: flow) → Map ACL

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PSTN Setup (Outbound + Inbound)

Step 1: Create Trunk

curl -X POST "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks" \
  -H "Content-Type: application/json" \
  -d '{
    "trunk_name": "my_trunk",
    "nso_code": "ANY-ANY",
    "domain_name": "<your_sid>.pstn.exotel.com"
  }'

Save trunk_sid from response!

Step 2: Map Phone Number to Trunk

curl -X POST "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/phone-numbers" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+919876543210"
  }'

Save id from response (needed for Update Mode API).

Step 3: Map ACL to Trunk (for Outbound/Termination)

curl -X POST "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/whitelisted-ips" \
  -H "Content-Type: application/json" \
  -d '{
    "ip": "<your_server_ip>",
    "mask": 32
  }'

Step 4: Map Destination URI to Trunk (for Inbound/Origination)

Important: For IP destinations, map ACL first (Step 3). FQDNs don't need ACL mapping.

curl -X POST "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/destination-uris" \
  -H "Content-Type: application/json" \
  -d '{
    "destinations": [
      {
        "destination": "<your_server_ip>:5061;transport=tls"
      }
    ]
  }'

Step 5: for Inbound SIP

a. Create a Flow using Connect Applet in App Bazaar: https://my.in.exotel.com/apps

b. Use sip: in the Dial Whom field

c. Map DID to flow through Exophone: https://my.in.exotel.com/numbers

d. Check inbound call flow by dialling Exophone/phonenumber to your system via Exotel SIP trunking

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StreamKit Setup (Voice AI)

For connecting your Contact Center to Voice AI bots.

Step 1: Create Trunk

Same as PSTN Step 1.

Step 2: Map Phone Number (Flow Mode)- Procure SIP Exophone from Account or contact support

curl -X POST "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/phone-numbers" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+919876543210",
    "mode": "flow"
  }'

Note: mode: flow routes calls to Voice AI bot instead of PSTN.

Step 3: Map ACL to Trunk

Same as PSTN Step 3.

Step 4: Build Flow and Map DID

a. Follow https://docs.exotel.com/exotel-agentstream/streamkit-cloud for end-to-end steps

b. Create flow in AppBazaar with Voicebot applet and passthru applet: https://my.in.exotel.com/apps

b. Map DID to flow through Exophone: https://my.in.exotel.com/numbers

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Manage & View

Update Phone Number Mode (pstn ↔ flow)

curl -X PUT "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/phone-numbers/<phone_number_id>" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+919876543210",
    "mode": "flow"
  }'

Note: <phone_number_id> is the numeric ID (e.g., 41523) from Map Phone Number response, NOT the phone number!

Set Trunk Alias (Caller ID for Outbound)

curl -X POST "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/settings" \
  -H "Content-Type: application/json" \
  -d '{
    "settings": [
      {
        "name": "trunk_external_alias",
        "value": "+919876543210"
      }
    ]
  }'

View Configurations

# Get phone numbers
curl -X GET "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/phone-numbers"

# Get ACLs (whitelisted IPs)
curl -X GET "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/whitelisted-ips"

# Get destination URIs
curl -X GET "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks/<trunk_sid>/destination-uris"

Delete Trunk

curl -X DELETE "https://<your_api_key>:<your_api_token>@<subdomain>/v2/accounts/<your_sid>/trunks?trunk_sid=<trunk_sid>"

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Authentication

Setting	Value
Base URL	https://<subdomain>
Subdomain (India)	api.in.exotel.com
Subdomain (Singapore)	api.exotel.com
Auth	HTTP Basic (<api_key>:<api_token>)
Content-Type	application/json
Rate Limit	200 requests/minute

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Mode Options

Mode	Description
pstn	Routes calls to telephone network (default)
flow	Routes calls to Voice AI bot (StreamKit)

Configure the network and firewall on your SIP system side to receive or send an invite from Exotel

Follow Exotel SIP Network and configuration Guide :https://docs.exotel.com/dynamic-sip-trunking

Resources

Resource	Description
API Reference	Full request/response details with examples
SIP Guide	Concepts, troubleshooting, PBX config
Postman Collection	Import & test APIs
curl Scripts	Ready-to-use bash scripts

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Common Errors

Error	Cause	Solution
HTTP 415	Wrong content type	Use Content-Type: application/json
"Destination not whitelisted"	IP not in ACL	Map ACL before mapping as destination
Duplicate resource (1008)	Already exists	Use different name/IP or delete existing

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Support

• Documentation: https://developer.exotel.com
• Email: support@exotel.com