Outbound Calls - RevRing AI Documentation

Configure your AI agents to initiate outbound phone calls for sales, surveys, reminders, and more.

How Outbound Calls Work

When you send an outbound call through RevRing:

You specify the agent, from number (caller ID), to number (recipient), and optional variables
RevRing initiates the call through your SIP trunk
When the recipient answers, the agent begins speaking based on its first message and prompt
The conversation proceeds according to your agent’s configuration
After the call ends, RevRing sends complete call details to your post-call webhook (if configured)

Sending Test Calls via Dashboard

Using the Send Call Page

The Send Call page is the primary way to test outbound calls from the dashboard.

Navigate to Send Call
Select your Agent from the dropdown
Enter the From Number (must be a number on your SIP trunk, E.164 format)
Enter the To Number (the recipient’s phone number, E.164 format)
Optionally set a Caller ID Name (up to 15 characters)
Add Variables if your prompt uses dynamic content
Click Send Test Call

The Live Transcript card on the right updates in real time as the conversation progresses. After the call ends, click View full call details to see the recording, summary, and metrics.

Save frequently used configurations by entering a name and clicking Save Config. Load saved configs from the dropdown to quickly re-run tests with different scenarios.

Using the Test Panel

The test panel on the right side of the agent page lets you call your agent directly from the browser via WebRTC. This is useful for quick iteration — you can tweak the prompt and immediately test without needing a phone. Use Test Variables to set direction, customer_name, or any other variables your prompt expects. To test outbound calling over the phone network (with real caller ID and SIP routing), use the Send Call page instead.

Sending Calls via API

For production outbound calling at scale, use the RevRing API.

Basic Outbound Call

curl -X POST https://api.revring.ai/v1/calls \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agentId": "agent_id_here",
    "fromNumber": "+12025551234",
    "toNumber": "+14155552671"
  }'

With Caller ID Name

You can set a custom caller ID name (up to 15 characters) that is displayed to the recipient when the call arrives:

curl -X POST https://api.revring.ai/v1/calls \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agentId": "agent_id_here",
    "fromNumber": "+12025551234",
    "toNumber": "+14155552671",
    "callerIdName": "Acme Support"
  }'

Caller ID name support depends on your SIP trunk provider and the recipient’s carrier. Not all carriers display the caller ID name.

With Custom Variables

curl -X POST https://api.revring.ai/v1/calls \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agentId": "agent_id_here",
    "fromNumber": "+12025551234",
    "toNumber": "+14155552671",
    "variables": {
      "customer_name": "John Smith",
      "appointment_time": "2:00 PM today",
      "confirmation_code": "ABC123"
    }
  }'

The API returns a call object with an id that you can use to track the call’s status. See the API Reference for complete documentation.

Configuring Outbound Agent Behavior

First Message

For outbound calls, the first message is critical since you’re initiating contact. Configure it in the Overview tab:

Hi {{customer_name}}, this is Alex calling from Acme Corp regarding your appointment scheduled for {{appointment_time}}. Is now a good time to talk?

Unlike inbound calls where leaving first message empty makes sense, outbound calls should almost always include a first message to properly introduce the purpose of the call.

Outbound-Specific Prompts

Tailor your prompt for outbound scenarios:

You are making an outbound call to confirm a customer's appointment. Your goals:

1. Verify the customer is available to talk (ask permission)
2. Confirm their appointment for {{appointment_time}}
3. Answer any questions about the appointment
4. Offer to reschedule if needed
5. Thank them and end the call politely

If they ask to be removed from future calls, acknowledge and confirm you'll update their preferences.

Keep the call brief (under 2 minutes) and respectful of their time.

Using Variables for Personalization

Variables allow you to customize each call without changing the agent configuration:

Reference variables in your prompt and first message using {{variable_name}} syntax
Pass variable values when sending the call via API or dashboard
The agent will replace placeholders with the actual values during the conversation

Common variable use cases:

Customer name, account number, order ID
Appointment dates and times
Custom messages or offers
Callback reasons or context

Voicemail Detection

Voicemail detection is particularly useful for outbound calling to avoid wasting resources on unanswered calls.

Enable Voicemail Detection

Navigate to the Tools tab
Locate Voicemail Detection under System Tools
Click Configure
Choose your action:
- Hangup: End the call immediately when voicemail is detected (saves costs)
- Leave Message: Speak a pre-recorded message before hanging up

If leaving a message, configure the voicemail message:

Hi, this is Acme Corp calling to confirm your appointment. Please call us back at 1-800-555-0123 at your earliest convenience. Thank you.

Click Save

For high-volume outbound campaigns, choose “Hangup” to minimize costs and focus agent time on live conversations.

Call Pacing and Concurrency

Understanding Concurrency Limits

RevRing enforces a concurrency limit on the maximum number of simultaneous calls per organization. You can view your current limit and usage on the Billing page.

Call Queuing

When you send an outbound call and all concurrent call slots are in use, RevRing automatically queues the call. Queued calls are dispatched in order as slots become available. While a call is waiting, its status is QUEUED. Once a slot opens and the call is dispatched, the status transitions to INITIATED and then ONGOING when the recipient answers. You can check a call’s status at any time:

curl https://api.revring.ai/v1/calls/{callId} \
  -H "x-api-key: YOUR_API_KEY"

To cancel a queued call before it is dispatched:

curl -X POST https://api.revring.ai/v1/calls/{callId}/cancel \
  -H "x-api-key: YOUR_API_KEY"

Only calls with status QUEUED can be cancelled. Once a call moves to INITIATED or ONGOING, it cannot be cancelled through this endpoint.

Opting Out of Queuing

If you prefer to handle queuing in your own system, pass skipQueue: true when creating the call. This tells RevRing to return an immediate 429 error instead of queuing when the concurrency limit is reached:

curl -X POST https://api.revring.ai/v1/calls \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agentId": "agent_id_here",
    "fromNumber": "+12025551234",
    "toNumber": "+14155552671",
    "skipQueue": true
  }'

Response when at capacity (429):

{
  "error": "concurrency_limit"
}

Best Practices for High Volume

Leverage built-in queuing: Let RevRing queue calls automatically rather than managing pacing yourself
Monitor active calls: Track concurrent calls via the Analytics API
Cancel unnecessary queued calls: If priorities change, cancel queued calls that are no longer needed
Handle errors gracefully: Implement retry logic with exponential backoff for non-queued calls
Respect time zones: Schedule calls during appropriate hours for the recipient’s location

Monitoring Outbound Calls

Real-Time Monitoring

View active outbound calls on the Overview page:

Active Calls: See current ongoing outbound calls
Filter by agent to monitor specific campaigns

Call Logs

Track all outbound calls in Call Logs:

Filter by Direction: Select “Outbound”
Filter by Status: View completed, failed, ongoing, or canceled calls
Filter by Agent: Focus on specific agents or campaigns
Click any call to view:
- Complete transcript
- Call recording
- Duration and timestamps
- Variables used
- Hangup cause and error messages (if applicable)

Success Metrics

Monitor key metrics to optimize your outbound campaigns:

Connection rate: Percentage of calls that connect vs. no answer/busy
Average duration: Typical call length for successful connections
Completion rate: Calls that reach the intended outcome
Cost per call: Track expenses across campaigns

Advanced Features

Post-Call Webhooks

Receive call results immediately after each call ends:

Configure Post-call Webhook URL in the Advanced tab:
```
https://api.yourcompany.com/webhooks/post-call
```
RevRing will POST complete call details including:
- Transcript
- Recording URL
- Call duration and timestamps
- Variables used
- AI-generated summary

Use this to:

Update your CRM with call outcomes
Trigger follow-up actions
Track campaign performance
Schedule callbacks for unsuccessful attempts

See the Webhooks guide for implementation details.

Call Transfer

Enable transfers to allow the agent to escalate to a human representative:

Navigate to the Tools tab
Click Configure on the Transfer tool
Add transfer routes:
- To number: +12025559999 (your sales team)
- Condition: When the customer wants to speak with a human or has complex questions
Click Save

The agent will offer to transfer when the condition is met.

End Call Control

Configure when the agent should end calls:

Navigate to the Tools tab
Click Configure on the End Call tool

Set custom end call rules:

End the call when:
- The customer confirms their appointment
- The customer declines and asks not to be called again
- The customer is not available and asks to call back later
- You've been speaking for more than 3 minutes

Click Save

Compliance and Best Practices

Legal Requirements

When making outbound calls, ensure compliance with:

TCPA (US): Obtain prior express written consent for marketing calls
TSR (US): Maintain do-not-call lists and honor opt-out requests
GDPR (EU): Respect data protection and privacy regulations
Local regulations: Follow country-specific telemarketing laws

You are responsible for ensuring compliance with all applicable laws and regulations. RevRing provides the technical platform but does not provide legal advice.

Best Practices

Respect time zones: Call during appropriate hours (typically 9 AM - 9 PM local time)
Honor opt-outs: Immediately stop calling anyone who requests removal
Clear identification: Always identify your company and purpose clearly
Keep it brief: Respect the recipient’s time with concise, focused calls
Professional tone: Use appropriate language and maintain a professional demeanor
Quality over quantity: Focus on successful conversations, not just call volume

Common Use Cases

Appointment Reminders

Hi {{customer_name}}, this is Acme Dental calling to remind you about your appointment tomorrow at {{appointment_time}} with Dr. {{doctor_name}}. 

Please respond with "confirm" if you'll be able to make it, or let me know if you need to reschedule.

Sales Follow-Up

Hi {{lead_name}}, this is {{agent_name}} from {{company_name}}. You recently expressed interest in {{product_name}} on our website. 

I'm calling to see if you have any questions and to share how we can help {{solve_problem}}.

Survey and Feedback

Hi {{customer_name}}, this is a brief call from Acme Corp. We recently helped you with {{service_type}} and would love to get your feedback. 

On a scale of 1 to 10, how satisfied were you with our service?

Payment Reminders

Hi {{customer_name}}, this is Acme Billing. We're calling about invoice {{invoice_number}} with a balance of {{amount}} due on {{due_date}}.

Are you able to make a payment today, or would you like to discuss payment options?

Troubleshooting

Calls fail to connect

Verify the from number is assigned to your SIP trunk
Ensure the to number is in valid E.164 format
Check your SIP trunk has sufficient capacity and balance
Review your telephony provider’s outbound restrictions
Confirm the destination country is allowed by your provider

Voicemail detection not working

Ensure voicemail detection is enabled in the Tools tab
Verify the action (hangup or leave message) is configured
Check the call recording to confirm voicemail was actually reached
Some voicemail systems may not be detectable - this is a known limitation

Variables not populating

Verify variable names match exactly between API call and prompt (case-sensitive)
Check that variables are passed in the API request body
Ensure variable syntax in prompt uses double curly braces: {{variable}}
Review the call transcript to see what was actually spoken

High failure rate

Check if you’re calling valid, reachable numbers
Verify caller ID (from number) is not flagged as spam
Consider time of day - avoid early morning or late evening
Review hangup causes in call logs to identify patterns
Ensure your first message clearly identifies the caller

Hit concurrency limit (429 error)

Implement exponential backoff and retry logic
Reduce call pacing or batch size
Check your current limit and usage at Billing
Monitor active calls before sending new batches
Contact support to discuss increasing your organization’s limit

Next Steps

Tools

Configure transfer, voicemail, and custom tools

Webhooks

Implement post-call webhooks to capture results

API Reference

View complete API documentation for sending calls

Call Logs

Query and analyze call history via API

Getting started

Platform

​How Outbound Calls Work

​Sending Test Calls via Dashboard

​Using the Send Call Page

​Using the Test Panel

​Sending Calls via API

​Basic Outbound Call

​With Caller ID Name

​With Custom Variables

​Configuring Outbound Agent Behavior

​First Message

​Outbound-Specific Prompts

​Using Variables for Personalization

​Voicemail Detection

​Enable Voicemail Detection

​Call Pacing and Concurrency

​Understanding Concurrency Limits

​Call Queuing

​Opting Out of Queuing

​Best Practices for High Volume

​Monitoring Outbound Calls

​Real-Time Monitoring

​Call Logs

​Success Metrics

​Advanced Features

​Post-Call Webhooks

​Call Transfer

​End Call Control

​Compliance and Best Practices

​Legal Requirements

​Best Practices

​Common Use Cases

​Appointment Reminders

​Sales Follow-Up

​Survey and Feedback

​Payment Reminders

​Troubleshooting

​Next Steps

Tools

Webhooks

API Reference

Call Logs

How Outbound Calls Work

Sending Test Calls via Dashboard

Using the Send Call Page

Using the Test Panel

Sending Calls via API

Basic Outbound Call

With Caller ID Name

With Custom Variables

Configuring Outbound Agent Behavior

First Message

Outbound-Specific Prompts

Using Variables for Personalization

Voicemail Detection

Enable Voicemail Detection

Call Pacing and Concurrency

Understanding Concurrency Limits

Call Queuing

Opting Out of Queuing

Best Practices for High Volume

Monitoring Outbound Calls

Real-Time Monitoring

Call Logs

Success Metrics

Advanced Features

Post-Call Webhooks

Call Transfer

End Call Control

Compliance and Best Practices

Legal Requirements

Best Practices

Common Use Cases

Appointment Reminders

Sales Follow-Up

Survey and Feedback

Payment Reminders

Troubleshooting

Next Steps