Auto-retry for failed calls

What is Auto-retry?

Auto-retry automatically reschedules calls that fail to connect. When a call ends with statuses like no-answer or busy, Bolna retries the call after a configurable delay, improving your overall contact rates without manual intervention.

How to enable Auto-retry

Add the retry_config object when making a call via the Make Call API or Create Batch API.

curl -X POST 'https://api.bolna.ai/call' \
-H 'Authorization: Bearer <api_key>' \
-H 'Content-Type: application/json' \
-d '{
  "agent_id": "your-agent-id",
  "recipient_phone_number": "+1234567890",
  "retry_config": {
    "enabled": true,
    "max_retries": 3,
    "retry_on_statuses": ["no-answer", "busy", "failed"],
    "retry_intervals_minutes": [30, 60, 120]
  }
}'

curl -X POST 'https://api.bolna.ai/batches' \
-H 'Authorization: Bearer <api_key>' \
-F 'agent_id=your-agent-id' \
-F 'file=@contacts.csv' \
-F 'retry_config={"enabled":true,"max_retries":2,"retry_intervals_minutes":[15,30],"prioritize_retries":true}'

Configuration options

Parameter	Type	Default	Description
`enabled`	boolean	`false`	Enable auto-retry
`max_retries`	integer	`3`	Maximum retry attempts (1–3)
`retry_on_statuses`	array	`["no-answer", "busy", "failed"]`	Statuses that trigger a retry
`retry_on_voicemail`	boolean	`false`	Retry if voicemail is detected
`retry_intervals_minutes`	array	`[30, 60, 120]`	Delay (in minutes) before each retry attempt
`prioritize_retries`	boolean	`false`	Place retries at the front of the dispatch queue once their delay elapses

Retry queue priority

By default a retry is queued behind the calls still waiting in its batch, so with a large batch the retry may only dial well after the configured delay has passed. Set prioritize_retries: true to push the retry to the front of the queue as soon as its delay elapses, so it dials ahead of the remaining pending calls:

{
  "enabled": true,
  "max_retries": 3,
  "retry_intervals_minutes": [15, 30],
  "prioritize_retries": true
}

Supported retry statuses

Status	Description
`no-answer`	Call rang but was not answered
`busy`	Line was busy
`failed`	Call failed to connect
`error`	Technical error occurred

Monitoring retries via webhook

When auto-retry is configured, your webhook receives retry information with each status update:

{
  "id": "execution-id",
  "status": "scheduled",
  "retry_count": 1,
  "retry_config": {
    "enabled": true,
    "max_retries": 3
  },
  "retry_history": [
    {
      "attempt": 1,
      "status": "no-answer",
      "at": "2026-01-26T10:00:00Z"
    }
  ],
  "scheduled_at": "2026-01-26T10:30:00Z"
}

Best practices

Conservative intervals

Start with 30+ minute intervals to avoid annoying contacts with rapid retries

Skip voicemail retries

Keep retry_on_voicemail: false (default) to avoid repeated voicemail deposits

Monitor retry counts

Track retry_count in webhooks to measure retry effectiveness over time

Match urgency

Use 1–2 retries for time-sensitive calls, 3 for lead outreach campaigns

Batch calling

Run campaigns with thousands of contacts

Webhooks

Get real-time call status updates

Call details

View execution history and outcomes

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Auto-retry for failed calls

What is Auto-retry?

How to enable Auto-retry

Configuration options

Retry queue priority

Supported retry statuses

Monitoring retries via webhook

Best practices

Conservative intervals

Skip voicemail retries

Monitor retry counts

Match urgency

Batch calling

Webhooks

Call details

​What is Auto-retry?

​How to enable Auto-retry

​Configuration options

​Retry queue priority

​Supported retry statuses

​Monitoring retries via webhook

​Best practices

Conservative intervals

Skip voicemail retries

Monitor retry counts

Match urgency

​Related features

Batch calling

Webhooks

Call details

What is Auto-retry?

How to enable Auto-retry

Configuration options

Retry queue priority

Supported retry statuses

Monitoring retries via webhook

Best practices

Related features