> ## Documentation Index > Fetch the complete documentation index at: https://docs.persistence.dev/llms.txt > Use this file to discover all available pages before exploring further. # API-triggered calls > Start outbound call batches with the Persistence API. Use the public Calls API when your application needs to start outbound calls without creating a dashboard campaign. An outbound batch identifies the caller ID, recipients, concurrency, and optional schedule. Recipient metadata becomes call-specific context for the agent. You can use the phone number's assigned outbound agent or provide an agent override supported by the request. ## Before you call the API * Publish the agent version you intend to use. * Configure and activate the caller phone number. * Create an API key with the call permission required by the endpoint. * Validate every destination and remove recipients covered by DND requirements. * Choose a safe concurrency value for downstream actions and integrations. The API accepts up to 1,000 recipients in one batch. Inspect rejected recipients in the response instead of assuming the complete batch was accepted. Use the end-call endpoint only with the session identifier returned for the active call. Review the batch-call and end-call contracts.