Webhooks

Overview

Webhooks provide real-time notifications when events occur in your OpenPhone workspace, enabling powerful integrations and automated workflows. Configure webhooks to send event data to your applications instantly when calls complete, messages arrive, or contacts change.

How webhooks work

Event-driven notifications: Webhooks deliver instant notifications when specific events occur in your OpenPhone workspace. When an event triggers, OpenPhone sends an HTTP POST request to your specified URL with detailed event data. Typical workflow:

Configure webhook URL and select event types
OpenPhone monitors for specified events
When event occurs, OpenPhone sends POST request with event payload
Your application processes the event data and responds
OpenPhone logs the delivery status and retries if needed

Webhook configuration requires workspace Owner or Admin permissions. Settings are managed through web and desktop apps only.

Webhook configuration interface:

Webhook creation form in OpenPhone settings

Available webhook events

Messaging events

Text message notifications:

message.received: Text message received by workspace phone number (includes media attachments)
message.delivered: Text message sent from workspace and successfully delivered (includes media)

AI-powered insights:

call.summary.completed: AI-generated call summary available in event payload
call.transcript.completed: Complete call transcript available in event payload

Voice events

Call status notifications:

call.ringing: Incoming call being received by workspace phone number
call.completed: Call finished (answered or unanswered, may include voicemail)
call.recording.completed: Call recording available at provided URL

Contact events

Contact management:

contact.updated: Contact created or modified in workspace
contact.deleted: Contact removed from workspace

Setting up webhooks

Configuration requirements

Required parameters:

Parameter	Requirement	Description
URL	Required	Webhook handler endpoint (HTTPS strongly recommended for production)
Event types	Required	Select one or more event types to monitor
Resources	Required	Choose phone numbers (calls/messages) or users/groups (contacts) to monitor

Optional parameters:

Parameter	Description
Label	Descriptive name for webhook identification and management

Setup process

To create a webhook:

Navigate to Settings → Webhooks in OpenPhone
Click Create webhook
Enter your webhook handler URL
Select event types to monitor
Choose phone numbers or contact resources
Add optional label for identification
Save and test configuration

Building webhook handlers

Handler requirements

Technical specifications:

Accept HTTP POST requests at your webhook URL
Process JSON event payload in request body
Respond with 2xx HTTP status code within 10 seconds
Verify webhook signature for security
Handle retries and failures gracefully

Response handling:

Success: Return 2xx status code (no response body required)
Failure: Non-2xx response triggers OpenPhone retry sequence
Timeout: No response within 10 seconds initiates retries

Development flexibility: Webhook handlers can be built in any programming language that supports HTTP requests and responses. Deploy to cloud platforms, servers, or serverless functions.

Security and authentication

Webhook signature verification: All webhook calls include cryptographic signatures to verify authenticity and prevent spoofing attacks. Signature header format:

'openphone-signature': 'hmac;1;1639710054089;mw1K4fvh5m9XzsGon4C5N3KvL0bkmPZSAy
b/9Vms2Qo='

Signature structure:

<scheme>;<version>;<timestamp>;<signature>

Component	Description	Current Value
scheme	Signature algorithm	Always “hmac”
version	Signature version	Always “1”
timestamp	Signature generation time	Unix timestamp
signature	Base64 encoded HMAC signature	SHA256 digest

Signature verification process

Verification steps:

Extract components from openphone-signature header
Prepare signed data by concatenating timestamp + "." + payload
Decode signing key from base64 (available in webhook details)
Compute HMAC-SHA256 using decoded key and signed data
Compare result with signature from header

Important requirements:

Remove all whitespace and newlines from JSON payload before concatenation
Use binary form of base64-decoded signing key for HMAC computation
Ensure exact string matching for verification success

Getting your signing key:

Go to webhook details page in OpenPhone
Click ellipses (⋯) at top right
Select “Reveal signing secret”
Copy base64-encoded key for your application

Implementation examples

Node.js webhook handler:

const express = require("express")
const bodyParser = require('body-parser')
const crypto = require('node:crypto');

const app = express()
const port = 8000

app.use(bodyParser.json())

app.post("/", function (req, res) {
  // signingKey is from "Reveal Signing Secret" in the OpenPhone app.
  const signingKey = 'R2ZLM2o0bFhBNVpyUnU2NG9mYXQ1MHNyR3pvSUhIVVg='

  // Parse the fields from the openphone-signature header.
  const signature = req.headers['openphone-signature']
  const fields = signature.split(';')
  const timestamp = fields[2]
  const providedDigest = fields[3]

  // Compute the data covered by the signature.
  const signedData = timestamp + '.' + JSON.stringify(req.body)

  // Convert the base64-encoded signing key to binary.
  const signingKeyBinary = Buffer.from(signingKey, 'base64').toString('binary')

  // Compute the SHA256 HMAC digest.
  const computedDigest = crypto.createHmac('sha256',signingKeyBinary)
    .update(Buffer.from(signedData,'utf8'))
    .digest('base64')

  // Verify signature matches
  if (providedDigest === computedDigest) {
    console.log(`signature verification succeeded`)
    // Process webhook event here
  } else {
    console.log(`signature verification failed`)
    return res.status(401).send('Unauthorized')
  }

  res.send({})
});

app.listen(port, function () {
  console.log(`webhook server listening on port ${port}`)
})

Python webhook handler:

import base64
import hmac
from flask import Flask, request, jsonify

app = Flask(__name__)

@app.route('/', methods=['POST'])
def handle_webhook_call():
    # signingKey is from "Reveal Signing Secret" in the OpenPhone app.
    signing_key = 'R2ZLM2o0bFhBNVpyUnU2NG9mYXQ1MHNyR3pvSUhIVVg='

    # Parse the fields from the openphone-signature header.
    signature = request.headers['openphone-signature']
    fields = signature.split(';')
    timestamp = fields[2]
    provided_digest = fields[3]

    # Compute the data covered by the signature as bytes.
    signed_data_bytes = b''.join([timestamp.encode(), b'.', request.data])

    # Convert the base64-encoded signing key to bytes.
    signing_key_bytes = base64.b64decode(signing_key)

    # Compute the SHA256 HMAC digest.
    hmac_object = hmac.new(signing_key_bytes, signed_data_bytes, 'sha256')
    computed_digest = base64.b64encode(hmac_object.digest()).decode()

    # Verify signature matches
    if provided_digest == computed_digest:
        print('signature verification succeeded')
        # Process webhook event here
    else:
        print('signature verification failed')
        return jsonify({'error': 'Unauthorized'}), 401
        
    return jsonify({})

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8000, debug=True)

Future versions may include multiple signatures separated by commas. Split the header value on commas to handle multiple signatures if needed.

Security best practices

Replay attack protection: Implement timestamp validation to prevent replay attacks:

Compare signature timestamp with current time
Reject requests with timestamps outside acceptable tolerance (e.g., 5 minutes)
Each webhook call generates unique timestamp and signature
Retries automatically include new timestamps

Additional security measures:

Always use HTTPS URLs for production webhooks
Store signing keys securely (environment variables, secret management)
Implement proper error handling and logging
Consider rate limiting for webhook endpoints

Error handling and retries

Automatic retry system

Retry behavior:

Trigger conditions: Non-2xx response codes or 10-second timeout
Backoff strategy: Exponential backoff with increasing delays
Retry duration: Up to 3 days of retry attempts
Final failure: Email notification sent to webhook creator

Retry timeline:

Initial retries happen quickly for minimal delay
Delays increase exponentially with each attempt
Prioritizes delivery close to original event time
Automatic status tracking throughout process

Manual retry options

Webhook management:

View delivery status in OpenPhone webhook details
Manually retry failed webhook calls anytime
Failed webhooks marked with ‘failure’ status
Successful manual retries update status to ‘success’

Failure notifications

When retries exhaust:

Email alert sent to webhook creator
Webhook call marked as permanently failed
Event details preserved for manual review
Option to retry manually when issues resolved

Testing and validation

Development testing

Local testing options:

HTTP clients: Use cURL, Postman, or Insomnia to send test POST requests
Local URLs: Test against localhost during development
Mock payloads: Create sample event JSON matching OpenPhone format
Signature testing: Verify HMAC validation logic with test keys

OpenPhone test features

Built-in test request:

Navigate to webhook details page in OpenPhone
Click ellipses (⋯) at top right
Select “Send Test Request”
OpenPhone sends sample event to your webhook URL
Verify signature verification and response handling

Test requests require publicly accessible webhook URLs. Local development URLs won’t work with OpenPhone’s test feature.

Live event testing

Real event triggers:

Configure webhook for specific event type (e.g., message.received)
Select your OpenPhone number in webhook resources
Trigger actual event (send text to your number)
Monitor webhook delivery and processing
Verify complete end-to-end functionality

Testing checklist:

[ ] Webhook receives POST requests correctly
[ ] Signature verification works
[ ] Event payload parsing succeeds
[ ] Application logic processes events properly
[ ] Error responses trigger retries
[ ] Success responses stop retry sequence

Troubleshooting

Common issues and solutions

Configuration problems:

Verify webhook URL is correct and accessible
Check webhook status is enabled in settings
Confirm event types are properly selected
Validate resources (phone numbers/users/groups) are correct

Response issues:

HTTP status codes: Ensure 2xx responses for successful processing
Response timing: Return responses within 10-second timeout
Error handling: Implement proper error responses for debugging

Security verification:

Signature validation: Verify HMAC signature computation
Key format: Ensure signing key is properly base64 decoded
Timestamp handling: Check timestamp extraction and concatenation

Debugging tools

Event monitoring:

Events log: View delivery history in webhook details page
Status tracking: Monitor success/failure rates
Retry attempts: Review automatic retry sequences
Manual testing: Use “Send Test Request” for immediate validation

Performance optimization:

Response time: Keep processing under 10 seconds
Error rates: Minimize failures to reduce retry overhead
Logging: Implement comprehensive request/response logging
Monitoring: Set up alerts for webhook delivery failures

Event payload examples

Message events

message.received payload:

{  
  "id": "EVc67ec998b35c41d388af50799aeeba3e",  
  "object": "event",  
  "apiVersion": "v2",  
  "createdAt": "2022-01-23T16:55:52.557Z",  
  "type": "message.received",  
  "data": {  
    "object": {  
      "id": "AC24a8b8321c4f4cf2be110f4250793d51",  
      "object": "message",  
      "from": "+14155550100",  
      "to": "+13105550199",  
      "direction": "incoming",  
      "body": "Hello",  
      "media": [  
        {  
         "url": "https://storage.googleapis.com/opstatics-dev/6c908000ada94d9fb206649ecb8cc928",  
         "type": "image/jpeg"  
        }  
      ],  
      "status": "received",  
      "createdAt": "2022-01-23T16:55:52.420Z",  
      "userId": "USu5AsEHuQ",  
      "phoneNumberId": "PNtoDbDhuz",  
      "conversationId": "CN78ba0373683c48fd8fd96bc836c51f79"  
    }  
  }  
}

message.delivered payload:

{  
  "id": "EVdefd85c2c3b740429cf28ade5b69bcba",  
  "object": "event",  
  "apiVersion": "v2",  
  "createdAt": "2022-01-23T17:05:56.220Z",  
  "type": "message.delivered",  
  "data": {  
    "object": {  
      "id": "ACcdcc2668c4134c3cbfdacb9e273cac6f",  
      "object": "message",  
      "from": "+13105550199",  
      "to": "+14155550100",  
      "direction": "outgoing",  
      "body": "Have a nice day",  
      "media": [  
        {  
         "url": "https://opstatics-dev.s3.amazonaws.com/i/ab6084db-5259-42c0-93c1-e17fb2628567.jpeg",  
         "type": "image/jpeg"  
        }  
      ],  
      "status": "delivered",  
      "createdAt": "2022-01-23T17:05:45.195Z",  
      "userId": "USu5AsEHuQ",  
      "phoneNumberId": "PNtoDbDhuz",  
      "conversationId": "CN78ba0373683c48fd8fd96bc836c51f79"  
    }  
  }  
}

Call events

call.ringing payload:

{  
  "id": "EV95c3708f9112412a834cc8d415470cd8",  
  "object": "event",  
  "apiVersion": "v2",  
  "createdAt": "2022-01-23T17:07:51.454Z",  
  "type": "call.ringing",  
  "data": {  
    "object": {  
      "id": "ACbaee66e137f0467dbed5ad4bc8d60800",  
      "object": "call",  
      "from": "+14155550100",  
      "to": "+13105550199",  
      "direction": "incoming",  
      "media": [],  
      "voicemail": null,  
      "status": "ringing",  
      "createdAt": "2022-01-23T17:07:51.116Z",  
      "answeredAt": null,  
      "completedAt": null,  
      "userId": "USu5AsEHuQ",  
      "phoneNumberId": "PNtoDbDhuz",  
      "conversationId": "CN78ba0373683c48fd8fd96bc836c51f79"  
    }  
  }  
}

call.completed (incoming with voicemail):

{  
  "id": "EVd39d3c8d6f244d21a9131de4fc9350d0",  
  "object": "event",  
  "apiVersion": "v2",  
  "createdAt": "2022-01-24T19:22:25.427Z",  
  "type": "call.completed",  
  "data": {  
    "object": {  
      "id": "ACa29ee906a4e04312a6928427b1c21721",  
      "object": "call",  
      "from": "+14145550100",  
      "to": "+13105550199",  
      "direction": "incoming",  
      "media": [],  
      "voicemail": {  
        "url": "https://m.openph.one/static/85ad4740be6048e4a80efb268d347482.mp3",  
        "type": "audio/mpeg",  
        "duration": 7  
      },  
      "status": "completed",  
      "createdAt": "2022-01-24T19:21:59.545Z",  
      "answeredAt": null,  
      "completedAt": "2022-01-24T19:22:19.000Z",  
      "userId": "USu5AsEHuQ",  
      "phoneNumberId": "PNtoDbDhuz",  
      "conversationId": "CN78ba0373683c48fd8fd96bc836c51f79"  
    }  
  }  
}

call.completed (outgoing answered call):

{  
  "id": "EV348de11e4b134fa48017ac45a251dd3e",  
  "object": "event",  
  "apiVersion": "v2",  
  "createdAt": "2022-01-24T19:28:45.370Z",  
  "type": "call.completed",  
  "data": {  
    "object": {  
      "id": "AC7ab6f57e62924294925d0ea961de7dc5",  
      "object": "call",  
      "from": "+13105550199",  
      "to": "+14155550100",  
      "direction": "outgoing",  
      "media": [],  
      "voicemail": null,  
      "status": "completed",  
      "createdAt": "2022-01-24T19:28:33.892Z",  
      "answeredAt": "2022-01-24T19:28:42.000Z",  
      "completedAt": "2022-01-24T19:28:45.000Z",  
      "userId": "USu5AsEHuQ",  
      "phoneNumberId": "PNtoDbDhuz",  
      "conversationId": "CN78ba0373683c48fd8fd96bc836c51f79"  
    }  
  }  
}

call.recording.completed payload:

{  
  "id": "EVda6e196255814311aaac1983005fa2d9",  
  "object": "event",  
  "apiVersion": "v2",  
  "createdAt": "2022-01-24T19:30:55.400Z",  
  "type": "call.recording.completed",  
  "data": {  
    "object": {  
      "id": "AC0d3b9011efa041d78c864019ad9e948c",  
      "object": "call",  
      "from": "+14155550100",  
      "to": "+13105550199",  
      "direction": "incoming",  
      "media": [  
        {   
          "url": "https://storage.googleapis.com/opstatics-dev/b5f839bc72a24b33a7fc032f78777146.mp3",  
          "type": "audio/mpeg",  
          "duration": 7  
        }  
      ],  
      "voicemail": null,  
      "status": "completed",  
      "createdAt": "2022-01-24T19:30:34.675Z",  
      "answeredAt": "2022-01-24T19:30:38.000Z",  
      "completedAt": "2022-01-24T19:30:48.000Z",  
      "userId": "USu5AsEHuQ",  
      "phoneNumberId": "PNtoDbDhuz",  
      "conversationId": "CN78ba0373683c48fd8fd96bc836c51f79"  
    }  
  }  
}

Contact events

contact.updated and contact.deleted payload:

{  
  "id": "EVe844e47e9fa4494d9acfa1144839ed94",  
  "object": "event",  
  "createdAt": "2022-01-24T19:44:09.579Z",  
  "apiVersion": "v2",  
  "type": "contact.updated",  
  "data": {  
    "object": {  
      "id": "CT61eeff33f3b14cfe6358cb52",  
      "object": "contact",  
      "firstName": "Jane",  
      "lastName": "Smith",  
      "company": "Comp Inc",  
      "role": "Agent",  
      "pictureUrl": null,  
      "fields": [  
         {  
           "name": "Phone",  
           "type": "phone-number",  
           "value": "+14155551212"  
         },  
         {  
           "name": "Email",  
           "type": "email",  
           "value": null  
         },  
         {  
           "name": "Prop1",  
           "type": "string",  
           "value": "Value12"  
         }  
      ],  
      "notes": [  
        {  
          "text": "@USu5AsEHuQ mynote 😂",  
          "enrichment": {  
            "taggedIds": {   
              "groupIds": [],   
              "userIds": [  
                "USu5AsEHuQ"  
              ],  
              "orgIds": []  
            },  
            "tokens": {   
              "USu5AsEHuQ": {   
                "token": "USu5AsEHuQ",   
                "replacement": "Tom Smith",   
                "type": "mention",   
                "locations": [  
                  {   
                    "startIndex": 1,   
                    "endIndex": 11   
                  }  
                ]   
              }   
            }   
          },  
          "createdAt": "2022-01-24T19:35:38.323Z",  
          "updatedAt": "2022-01-24T19:35:38.323Z",  
          "userId": "USu5AsEHuQ"  
        }  
      ],  
      "sharedWith": [  
        "USu5AsEHuQ"  
       ],  
      "createdAt": "2022-01-24T19:35:38.318Z",  
      "updatedAt": "2022-01-24T19:44:09.565Z",  
      "userId": "USu5AsEHuQ"  
    }  
  }  
}

AI analysis events

call.summary.completed payload:

{  
  "id": "EVc86d16fed5314cf6bd7bf13f11c65fd2",  
  "object": "event",  
  "apiVersion": "v3",  
  "createdAt": "2024-09-05T15:30:24.213Z",  
  "type": "call.summary.completed",  
  "data": {  
    "object": {  
      "object": "callSummary",  
      "callId": "AC641569d25e0a4489ad807409d9bee3fd",  
      "status": "completed",  
      "summary": [  
        "this is your call summary."  
      ],  
      "nextSteps": [  
        "these are your next steps."  
      ]  
    }  
  }  
}

call.transcript.completed payload:

{  
  "id": "EV67e3564088bf4badb6593cd7db8f2832",  
  "object": "event",  
  "apiVersion": "v3",  
  "createdAt": "2024-09-05T15:30:18.629Z",  
  "type": "call.transcript.completed",  
  "data": {  
    "object": {  
      "object": "callTranscript",  
      "callId": "AC741569d25e0a4489ad804709d9bee3fc",  
      "createdAt": "2024-09-05T15:30:18.198Z",  
      "dialogue": [  
        {  
          "end": 73.57498,  
          "start": 0.03998,  
          "userId": "UStpTEr9a6",  
          "content": "hello world",  
          "identifier": "+12345678901"  
        },  
        {  
          "end": 1.52,  
          "start": 1.12,  
          "userId": "USiAYGldYE",  
          "content": "hi there",  
          "identifier": "+19876543210"  
        }  
      ],  
      "duration": 87.614685,  
      "status": "completed"  
    }  
  }  
}

Additional resources

Need help? Submit a support request at support.openphone.com for technical assistance with webhook implementation.

Getting started

Core concepts

Troubleshooting

Contact Support

Community

Overview

How webhooks work

Available webhook events

Messaging events

Voice events

Contact events

Setting up webhooks

Configuration requirements

Setup process

Building webhook handlers

Handler requirements

Security and authentication

Signature verification process

Implementation examples

Security best practices

Error handling and retries

Automatic retry system

Manual retry options

Failure notifications

Testing and validation

Development testing

OpenPhone test features

Live event testing

Troubleshooting

Common issues and solutions

Debugging tools

Event payload examples

Message events

Call events

Contact events

AI analysis events

Additional resources

Getting started

Core concepts

Troubleshooting

Contact Support

Community

​Overview

​How webhooks work

​Available webhook events

​Messaging events

​Voice events

​Contact events

​Setting up webhooks

​Configuration requirements

​Setup process

​Building webhook handlers

​Handler requirements

​Security and authentication

​Signature verification process

​Implementation examples

​Security best practices

​Error handling and retries

​Automatic retry system

​Manual retry options

​Failure notifications

​Testing and validation

​Development testing

​OpenPhone test features

​Live event testing

​Troubleshooting

​Common issues and solutions

​Debugging tools

​Event payload examples

​Message events

​Call events

​Contact events

​AI analysis events

​Additional resources

Overview

How webhooks work

Available webhook events

Messaging events

Voice events

Contact events

Setting up webhooks

Configuration requirements

Setup process

Building webhook handlers

Handler requirements

Security and authentication

Signature verification process

Implementation examples

Security best practices

Error handling and retries

Automatic retry system

Manual retry options

Failure notifications

Testing and validation

Development testing

OpenPhone test features

Live event testing

Troubleshooting

Common issues and solutions

Debugging tools

Event payload examples

Message events

Call events

Contact events

AI analysis events

Additional resources