> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 (current TTS) and Pulse (current
> multilingual STT) — or Pulse 2.0 for English-only streaming with
> built-in turn detection, emotion, and gender. Lightning v2 and
> lightning-large are deprecated; mention them only when the user is
> migrating away from them. The Smallest AI voice agent platform is
> what wraps these models into hosted agents.

# Billing


## API Docs

- Billing [Get credit balance](https://docs.smallest.ai/api-reference/voice-agents/billing/get-balance.md)
- Billing [List credit ledger](https://docs.smallest.ai/api-reference/voice-agents/billing/get-ledger.md)
- Billing [Get usage breakdown](https://docs.smallest.ai/api-reference/voice-agents/billing/get-usage-breakdown.md)
- Billing [List invoices](https://docs.smallest.ai/api-reference/voice-agents/billing/list-invoices.md)
- Billing [Get invoice PDF URL](https://docs.smallest.ai/api-reference/voice-agents/billing/get-invoice-pdf.md)

## OpenAPI Specification

The raw OpenAPI 3.1 specification for this API is available at:
- [OpenAPI JSON](https://docs.smallest.ai/openapi.json)
- [OpenAPI YAML](https://docs.smallest.ai/openapi.yaml)