for (const number of phoneNumbers) { try { const call = await retell.call.createPhoneCall({ from_number: process.env.RETELL_PHONE_NUMBER!, to_number: number, override_agent_id: agentId, metadata: { campaign: 'appointment-reminder', date: '2026-04-01' }, }); console.log(Called ${number}: ${call.call_id}); } catch (err) { console.error(Failed to call ${number}: ${err.message}); } // Rate limit: space calls apart await new Promise(r => setTimeout(r, 2000)); }


### Step 2: List and Filter Calls

```typescript
const calls = await retell.call.list({
  sort_order: 'descending',
  limit: 20,
});
for (const call of calls) {
  console.log(`${call.call_id}: ${call.call_status} — ${call.end_timestamp - call.start_timestamp}ms`);
}

Step 3: Get Call Recording and Transcript

const callDetail = await retell.call.retrieve(callId);
if (callDetail.recording_url) {
  console.log(`Recording: ${callDetail.recording_url}`);
}
if (callDetail.transcript) {
  console.log(`Transcript:\n${callDetail.transcript}`);
}

Output

Outbound call campaign with rate limiting
Call listing with status and duration
Recordings and transcripts retrieved

Error Handling

Error	Cause	Solution
Call fails immediately	Bad phone number format	Use E.164 format
No recording	Recording not enabled	Enable in agent settings
Concurrent limit	Too many active calls	Upgrade plan or queue calls

Examples

Run a bounded outbound appointment reminder campaign

Upload only consented test contacts to a development campaign and set a small concurrency limit before enabling any production queue. For each test call, verify the E.164 number formatting, expected agent version, completion status, and redacted transcript retrieval. If a call result is ambiguous, query the call identifier before retrying so an operator does not create duplicate calls or overwrite the original outcome.

Resources

Next Steps

Handle call events: retellai-webhooks-events

retellai-core-workflow-b

Retell AI Core Workflow B

Overview

Prerequisites

Instructions

Step 1: Outbound Call Campaign