Skip to main content

​
Overview

API keys connect the CloseTheCall platform to the voice AI and telephony services that power your clients’ receptionists. You enter your keys once in Agency Settings > API Keys, and they are used for all client calls. All keys are encrypted with AES-256-GCM before storage. They are never stored in plain text, never logged, and decrypted only at the moment a call is made.

​
Required vs Optional Keys

KeyRequired?What It Powers
VAPI API KeyYesVoice AI calls (primary provider)
Retell API KeyNoAlternative voice AI provider
Bland API KeyNoBudget voice AI provider
Twilio Account SID + Auth TokenNoUse your own phone numbers instead of platform numbers
You must configure at least one voice provider key (VAPI is recommended). Without it, no AI calls can be made for your clients.
VAPI is the primary voice AI provider and offers the most features: function calling, knowledge base integration, call transfer, voicemail detection, and bilingual support.
1

Create a VAPI account

Go to dashboard.vapi.ai and sign up.
2

Navigate to API Keys

In the VAPI dashboard, go to Settings > API Keys.
3

Create or copy your key

Copy your API key. It starts with vapi_ followed by a long string.
4

Paste into CloseTheCall

Go to Agency Settings > API Keys and paste the key into the VAPI field. Click Save.
The system validates your key when you save it by making a test API call. If the key is invalid, you will see an error message and the key will not be saved.

​
Retell API Key (Optional)

Retell is a high-quality voice AI provider with low latency. It supports basic call flows and provisions phone numbers natively in multiple countries (including UK and AU) — so you do not need Twilio for international numbers. It does not have the full function calling or knowledge base capabilities of VAPI. See Voice Providers Explained for a full comparison.
1

Create a Retell account

Go to retell.ai and click Sign Up. Enter your email and create a password.
2

Open the dashboard

After verifying your email, log in to the Retell dashboard.
3

Navigate to Settings

In the left sidebar, click Settings. Then click API Key.
4

Copy your API key

Your API key is displayed on the settings page. Click the copy icon to copy it to your clipboard.
5

Paste into CloseTheCall

Go to Agency Settings > API Keys in your CloseTheCall dashboard. Paste the key into the Retell field. Click Save.
What happens after you save: The platform validates your key, then syncs all your client assistants to Retell. New phone numbers will be provisioned through Retell instead of Twilio/VAPI. All existing clients automatically switch to the Retell provider on their next call.

​
Bland API Key (Optional)

Bland is a budget-friendly voice AI option at ~$0.03-0.06/min. It works well for simple, high-volume call answering but has fewer customization options than VAPI or Retell. Like Retell, Bland provisions phone numbers natively in multiple countries — no Twilio needed. See Voice Providers Explained for a full comparison.
1

Create a Bland account

Go to bland.ai and click Sign Up. Enter your email and create a password.
2

Open the dashboard

After verifying your account, log in to the Bland dashboard.
3

Navigate to API Keys

In the dashboard, go to API Keys (typically in the settings or sidebar menu).
4

Copy your API key

Click Create Key if you do not have one yet, or copy your existing key.
5

Paste into CloseTheCall

Go to Agency Settings > API Keys in your CloseTheCall dashboard. Paste the key into the Bland field. Click Save.
What happens after you save: The platform validates your key, then syncs all your client assistants to Bland. New phone numbers will be provisioned through Bland instead of Twilio/VAPI. All existing clients automatically switch to the Bland provider on their next call.

​
Twilio Keys (Optional)

By default, phone numbers are provisioned from the platform’s Twilio account. If you want to use your own Twilio account (for number ownership, custom caller ID, or billing control), enter your Twilio credentials. You need two values:
  • Account SID — starts with AC, found on your Twilio dashboard home page
  • Auth Token — found next to Account SID (click to reveal)
Get both from twilio.com/console.
Using your own Twilio account means you own the phone numbers directly. If you ever leave CloseTheCall, the numbers stay with you. With platform numbers, numbers are returned when you cancel.

​
How Key Encryption Works

When you save an API key:
  1. The key is encrypted with AES-256-GCM using a platform encryption key
  2. The encrypted value is stored in the database
  3. When a call comes in, the key is decrypted in memory for that single API request
  4. The decrypted key is never written to logs, error reports, or cached
Keys are isolated per agency. Your keys are never shared with other agencies or used for platform operations.

​
Changing Keys

You can update any API key at any time:
  1. Go to Agency Settings > API Keys
  2. Enter the new key in the appropriate field
  3. Click Save
The new key takes effect on the next call. Calls already in progress continue using the previous key until they end.
If you rotate a key in your provider’s dashboard (VAPI, Retell, etc.), update it in CloseTheCall immediately. Calls will fail until the new key is saved.

​
Which Provider Should You Choose?

VAPI

Recommended
  • Full function calling (booking, lead capture)
  • Knowledge base integration
  • Call transfer to human
  • Voicemail detection
  • Bilingual support (5 languages)
  • ~$0.05/min

Retell

Simpler
  • Lower latency
  • Basic call flows
  • Limited function calling
  • Good for simple answering
  • ~$0.04/min

Bland

Budget
  • Lowest cost
  • Basic voice AI
  • Fewer customization options
  • Good for high-volume, simple calls
  • ~$0.03/min
Not currently. The voice provider is set at the agency level and applies to all clients. If you need per-client provider selection, contact support to discuss Enterprise options.
Calls will fail with a provider error. The AI will not answer, and calls will go to the client’s voicemail or ring through to their personal phone (depending on routing settings). Top up your VAPI balance at dashboard.vapi.ai to restore service.
CloseTheCall — AI Receptionist for Local Businesses · Built by Quantum AI WebApps Digital LLC · Dashboard · Support · © 2026