catalog / stepfun-ai

StepFun's 600B sparse MoE flagship (27B active) — agentic coding and long-horizon work with a 1M-token context window, tool calling, and structured output. Open weights under the StepFun Model License.

Send stepfun-ai/Step-5-Preview to /v1/chat/completions — that is the channel name, not the catalog slug.

Discussion / source

Verified host.

Call it

curl https://api.demonroute.com/v1/chat/completions \
  -H "Authorization: Bearer $DEMONROUTE_API_KEY" \
  -d '{"model":"stepfun-ai/Step-5-Preview","messages":[{"role":"user","content":"ping"}]}'