Sesame

OpenRouter serves 1 Sesame model behind one OpenAI-compatible API. Create an OpenRouter API key, point your client at https://openrouter.ai/api/v1, and set the model to an ID such as sesame/csm-1b. The quickstart has request examples for every supported SDK.

CSM 1B has the largest context window of any Sesame model on OpenRouter, accepting up to 4,096 tokens per request.

CSM 1B is the most recently added Sesame model on OpenRouter, listed on April 23, 2026.