Quickstart (API)

Answer your first phone call with an AI agent: get an API key, create an agent, provision a phone number, and place a live test call — all through the REST API.

This guide walks you through the four REST calls it takes to answer your first phone call with an AI agent.

Step 1: Get an API key

Log in
Open app.thunderphone.com.
Navigate to Keys
Go to Organization → Keys in the dashboard.
Create a key
Click Create key, give it a name, and copy the sk_live_... value. The raw key is shown only once — store it in your secret manager immediately.

Throughout this guide, swap sk_live_YOUR_API_KEY with the value you just copied. The key identifies your organization automatically, so you never need to put an org id in URLs.

Step 2: Create an agent

An agent defines how the AI handles conversations — prompt, voice, product tier, tools, and widget eligibility.

cURL

curl -X POST https://api.thunderphone.com/v1/agents \
  -H "Authorization: Bearer sk_live_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name":   "Customer Support",
    "prompt": "You are a friendly support agent for Acme Corp. Help with orders, returns, and product info. Be concise and helpful.",
    "voice":  "john",
    "product": "spark"
  }'

Python

import os, requests
 
agent = requests.post(
    "https://api.thunderphone.com/v1/agents",
    headers={"Authorization": f"Bearer {os.environ['THUNDERPHONE_API_KEY']}"},
    json={
        "name":   "Customer Support",
        "prompt": "You are a friendly support agent for Acme Corp. Help with orders, returns, and product info. Be concise and helpful.",
        "voice":  "john",
        "product": "spark",
    },
).json()
print("Agent id:", agent["id"])

Node.js

const agent = await fetch("https://api.thunderphone.com/v1/agents", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.THUNDERPHONE_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    name:    "Customer Support",
    prompt:  "You are a friendly support agent for Acme Corp. Help with orders, returns, and product info. Be concise and helpful.",
    voice:   "john",
    product: "spark",
  }),
}).then((r) => r.json());
console.log("Agent id:", agent.id);

Step 3: Provision a phone number

This call asks ThunderPhone's demo pool for a number and assigns your new agent as the inbound handler. (To bring your own number from a VoIP provider, see VoIP connections instead.)

cURL

# First provision
curl -X POST https://api.thunderphone.com/v1/phone-numbers \
  -H "Authorization: Bearer sk_live_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"area_code": "415"}'
 
# Then assign the agent you created in Step 2
curl -X PATCH https://api.thunderphone.com/v1/phone-numbers/<id-from-previous> \
  -H "Authorization: Bearer sk_live_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"inbound_agent_id": 12}'

Python

number = requests.post(
    "https://api.thunderphone.com/v1/phone-numbers",
    headers={"Authorization": f"Bearer {os.environ['THUNDERPHONE_API_KEY']}"},
    json={"area_code": "415"},
).json()
requests.patch(
    f"https://api.thunderphone.com/v1/phone-numbers/{number['id']}",
    headers={"Authorization": f"Bearer {os.environ['THUNDERPHONE_API_KEY']}"},
    json={"inbound_agent_id": agent["id"]},
)
print("Your ThunderPhone number:", number["number"])

Your new number starts in status="provisioning" and transitions to active within a few seconds; by the time you hang up your browser the number is ready to take calls.

Step 4 (optional): Set up a webhook

For real-time events (dynamic call routing, post-call processing) add a webhook endpoint. Subscribe only to the events you need.

curl -X POST https://api.thunderphone.com/v1/developer/webhook-endpoints \
  -H "Authorization: Bearer sk_live_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "label":  "Prod webhook",
    "url":    "https://your-server.com/thunderphone-webhook",
    "events": ["telephony.incoming", "telephony.complete"]
  }'

The response contains a one-shot secret — copy it to your secret manager. Use that secret to verify the X-ThunderPhone-Signature header on incoming requests (see Webhooks overview).

Step 5: Test your agent

Call the number you just provisioned. The agent picks up, introduces itself, and follows your prompt.

Inspect the call after it ends:

curl https://api.thunderphone.com/v1/calls \
  -H "Authorization: Bearer sk_live_YOUR_API_KEY"

Drill into a specific call to fetch the transcript and recording URL:

curl https://api.thunderphone.com/v1/calls/{call_id}/transcript \
  -H "Authorization: Bearer sk_live_YOUR_API_KEY"
curl https://api.thunderphone.com/v1/calls/{call_id}/audio \
  -H "Authorization: Bearer sk_live_YOUR_API_KEY"

Next steps

Add function tools

Let your agent call your APIs during a conversation.

Place outbound calls

Trigger calls from your own code.

Handle webhooks

React to call events in real time.

Full API reference

Every public endpoint, documented.

Quickstart (API)

Step 1: Get an API key#

Step 2: Create an agent#

Step 3: Provision a phone number#

Step 4 (optional): Set up a webhook#

Step 5: Test your agent#

Next steps#