# Retellai Core Workflow B

> Retell AI core workflow b — AI voice agent and phone call automation. Use when working with Retell AI for voice agents, phone calls, or telephony. Trigger with phrases like "retell core workflow b", "retellai-core-workflow-b", "voice agent".

- Skill: `gabrielmoreira/retellai-core-workflow-b` (Agent Skill)
- Install (CLI): `npx skillmds@latest add gabrielmoreira/retellai-core-workflow-b`
- Raw SKILL.md: https://api.skillmd.com/api/skills/gabrielmoreira/retellai-core-workflow-b/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- License: MIT
- Author: gabrielmoreira (https://skillmd.com/u/gabrielmoreira)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/gabrielmoreira/retellai-core-workflow-b

---

# Retell AI Core Workflow B

## Overview

Manage phone calls: outbound campaigns, call transfers, recordings, and concurrent call handling.

## Prerequisites

- Completed `retellai-core-workflow-a`

## Instructions

### Step 1: Outbound Call Campaign

```typescript
const phoneNumbers = ['+14155551001', '+14155551002', '+14155551003'];

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

```typescript
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

- [Create Phone Call](https://docs.retellai.com/api-references/create-phone-call)
- [Retell AI Documentation](https://docs.retellai.com)

## Next Steps

Handle call events: `retellai-webhooks-events`