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Welcome to the Butter AI API reference. Our API is designed to be intuitive, allowing you to manage AI agents, telephony, and business knowledge with simple HTTP requests.

Base URL

All API requests should be made to:
https://api.getbutter.ai

Core Concepts

The API is organized around several key resources:
  • Agents: The brain of your application. Configure LLMs, voices, and personalities.
  • Phone Numbers: Buy or import numbers from Twilio or SIP providers to route calls.
  • Calls: Initiate outbound calls or track inbound call lifecycle events.
  • Knowledge Base: Manage the documents (RAG) that your agents reference during calls.
  • Tools: Define custom API endpoints that agents can call to perform actions.

Response Format

All responses are returned in standard JSON format. Successful requests typically return a 200 OK or 201 Created status code along with the requested data.
{
  "success": true,
  "agent": {
    "agent_id": "agent_123",
    "agent_name": "Sales Rep"
  }
}

Rate Limiting

The Butter AI API enforces rate limits based on your subscription tier. If you exceed these limits, the API will return a 429 Too Many Requests status code.
TierRate Limit
Starter10 requests per second
Pro50 requests per second
EnterpriseCustom
If you are planning a high-volume outbound campaign, please contact our support team to ensure your rate limits are increased accordingly.