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

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