---

name: retellai-install-auth description: "Retell AI install auth \u2014 AI voice agent and phone call automation.\n
Use when working with Retell AI for voice agents, phone calls, or telephony.\nTrigger
\ with phrases like "retell install auth", "retellai-install-auth", "voice
\ agent".\n" allowed-tools: Read, Write, Edit, Bash(npm:), Bash(curl:), Grep version: 1.9.0 license: MIT author: Jeremy Longshore jeremy@intentsolutions.io tags:

• saas
• retellai
• voice
• telephony
• ai-agents compatibility: Designed for Claude Code

---

Retell AI Install Auth

Overview

Install the Retell AI SDK and configure API key authentication for building voice agents.

Prerequisites

• Retell AI account at retellai.com
• API key from the Retell AI dashboard
• Node.js 18+ or Python 3.9+

Instructions

Step 1: Install SDK

set -euo pipefail
# Node.js
npm install retell-sdk

# Python
pip install retell-sdk

Step 2: Configure Environment

# .env
RETELL_API_KEY=key_xxxxxxxxxxxxxxxxxxxxxxxx

Step 3: Initialize Client (Node.js)

import Retell from 'retell-sdk';

const retell = new Retell({ apiKey: process.env.RETELL_API_KEY! });

// Verify connection — list agents
const agents = await retell.agent.list();
console.log(`Connected! ${agents.length} agent(s) configured.`);

Step 4: Initialize Client (Python)

from retell import Retell
import os

retell = Retell(api_key=os.environ["RETELL_API_KEY"])
agents = retell.agent.list()
print(f"Connected! {len(agents)} agent(s) configured.")

Output

• retell-sdk installed
• API key configured
• Connection verified with agent listing

Error Handling

Error	Cause	Solution
401 Unauthorized	Invalid API key	Verify key in Retell Dashboard
ModuleNotFoundError	SDK not installed	npm install retell-sdk
Connection timeout	Network issue	Check firewall allows HTTPS

Examples

Configure a least-privilege development credential

Store a non-production API key in the local secret manager or CI secret store, not in source control or a command history. Verify it by listing development agents and record only the account, environment, and verification time. If the test returns an authorization error, revoke the invalid credential rather than trying alternate keys in logs; use a separate production credential only in a protected deployment environment.

Resources

• Retell AI SDKs
• retell-sdk npm

Next Steps

Create your first agent: retellai-hello-world