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Do-Not-Call List

The Do-Not-Call (DNC) List tool checks phone numbers against your DNC registry before making outbound calls. This ensures compliance with telecommunications regulations (TCPA, FCC) and prevents calling numbers that have opted out.

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How It Works

-> Before outbound call, agent checks the target number
-> Agent calls check_dnc_list with phone_number="+14155551234"
-> Returns "CLEAR" or "BLOCKED"

If BLOCKED:
Agent: "I'm unable to call that number as it's on the Do-Not-Call list."

If CLEAR:
-> Outbound call proceeds normally

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Configuration

{
  "dncListEnabled": true,
  "dncListSource": "internal",
  "dncInternalNumbers": ["+14155551111", "+14155552222"],
  "dncCheckMode": "before_call",
  "dncBlockAction": "block",
  "dncApiUrl": ""
}
SettingTypeDefaultDescription
dncListEnabledbooleanfalseEnable DNC checking
dncListSourcestringinternalSource: internal (built-in list) or api (external service)
dncInternalNumbersstring[][]Phone numbers on the internal DNC list
dncCheckModestringbefore_callWhen to check: before_call or always
dncBlockActionstringblockOn DNC match: block (prevent call) or warn (proceed with warning)
dncApiUrlstring—External DNC API endpoint for api source

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LLM Tool

Tool name: check_dnc_list 
Parameters:
  phone_number: string (phone number to check)

Returns:
  "CLEAR: +14155551234 is not on the Do-Not-Call list. Safe to call."
  "BLOCKED: +14155551234 is on the Do-Not-Call list. This number cannot be called."
  "WARNING: +14155551234 is on the Do-Not-Call list. Proceed with caution."

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DNC Sources

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Internal List

Maintain your own DNC list directly in the agent configuration. Numbers are compared after stripping formatting.

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External API

Query an external DNC compliance service. The API receives a GET request: 
GET https://your-dnc-api.com/check?phone=+14155551234
Expected response: 
{
  "on_dnc_list": true,
  "blocked": true
}

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Example — Create Agent with DNC List

curl -X POST https://api.thinnest.ai/v1/agents \
  -H "Authorization: Bearer $THINNESTAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Outbound Sales Agent",
    "model": "gpt-4o",
    "instructions": "You make outbound sales calls. Before calling any number, check the DNC list first. If the number is blocked, do NOT call it.",
    "voiceEnabled": true,
    "transcriber": { "provider": "deepgram", "model": "nova-2-conversationalai" },
    "voice": { "provider": "deepgram", "voiceId": "aura-2-thalia-en" },
    "dncListEnabled": true,
    "dncListSource": "internal",
    "dncInternalNumbers": ["+14155551111", "+14155552222"],
    "dncCheckMode": "before_call",
    "dncBlockAction": "block"
  }'