---
id: "sesame/csm-1b"
also: ["sesame/csm-1b"]
cheapest_list_usd_per_m: "7.0 in, 0.0 out, at deepinfra on openrouter"
context: 4096
max_output: 3686
input: ["text"]
output: ["speech"]
released: "2026-04-23"
api: ["/api/v1/audio/speech"]
endpoints: 2
gateways: "openrouter (2)"
no_training: 1
trains: 0
retains_prompts: 0
---
# Sesame: CSM 1B

CSM 1B is a conversational speech model from Sesame. It accepts text input and produces English speech output, with voice options spanning conversational and read-speech styles. At 1B parameters, it...