# CSM 1B (Sesame) — API pricing and providers

> Conversational text-to-speech. Model id `sesame/csm-1b`. Audio model by Sesame.

- Page: https://infro.io/models/sesame/csm-1b
- Vendor: Sesame (https://infro.io/models/sesame)
- Modality: Audio
- Endpoint through INFRO: `POST /v1/audio/speech` at https://api.infro.io/v1
- List rate: $7.00 per 1M characters
- Rates checked: 2026-10-05

Rates are Sesame's published list price: what the customer's own provider account bills, not an INFRO charge. INFRO is a BYOK control plane; it charges a software subscription and adds 0% to model spend.

## Providers that serve it

| Provider | Model id sent |
| --- | --- |
| OpenRouter | `sesame/csm-1b` |

## Questions

### How much does the CSM 1B API cost?

Sesame's published list rate for CSM 1B is $7.00 per 1M characters (checked 2026-10-05). The provider account you connect bills you at the rate on that account, so a negotiated rate replaces the list rate. INFRO adds 0% to model spend.

### Which providers serve CSM 1B?

In INFRO's provider registry, CSM 1B can be served by OpenRouter. You connect your own account with any of them, and INFRO routes and fails over between the ones you connect.

### What is the CSM 1B model ID?

Request it from INFRO as "sesame/csm-1b". INFRO sends each provider its own id: OpenRouter "sesame/csm-1b".

### How do I call CSM 1B through an OpenAI-compatible API?

Point an OpenAI SDK, or any HTTP client, at https://api.infro.io/v1 with an INFRO gateway key and send model "sesame/csm-1b" to POST /v1/audio/speech. INFRO runs the request on a provider account you connected and returns the provider's response with an estimated cost.

### Does INFRO mark up CSM 1B usage?

No. Sesame or the provider you connect bills model usage to your own account. INFRO charges a software subscription for routing, failover, observability, budgets and policy, and takes 0% of model spend.