At a glance
Agents
Cartesia’s hosted Managed Agents are billed per minute in US dollars. This does not affect your credit balance.Text-to-speech
Standard TTS costs approximately 1 credit per character. The exact number of credits can vary slightly due to transcript pre-processing. This applies to every TTS endpoint:/tts/bytes, /tts/sse, and /tts/websocket.
Speech-to-text
STT pricing depends on the model and whether you use the batch or realtime endpoint. Silence is also included, even if no transcript is produced.Infill
Infill generates audio that bridges two existing clips. Each request costs a fixed 300 credits, plus the standard TTS rate applied to the infill transcript.Check your usage
You can check your usage on the usage page and view your current balance on the subscription page. Additionally, you can use the credit usage and agent usage API to check usage programmatically. This requires creating an admin API key.Running out of credits
When your monthly credit allotment is used up, what happens next depends on whether overages are enabled for your workspace.- Overages enabled: requests continue to succeed past your monthly allotment and the extra usage is billed as an overage on top of your subscription. Your credit balance can go negative during the billing period; the negative number reflects credits used beyond your allotment. Toggle overages on the subscription page.
- Overages disabled: requests that would exceed your allotment fail until the next renewal or until you upgrade your plan.