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RedRouterRedRouter

Step 5 Preview

step-5-previewAvailable

StepFun's Step 5 Preview for chat, reasoning, and tool use. Preview models may change or be withdrawn upstream.

Input
$1.26
Cached input
$0.13
Output
$3.40

per 1M tokens

Context
1M
Max output
8.2K
Tool callingJSON outputOpenAI Chat CompletionsOpenAI ResponsesAnthropic Messages

Quickstart

Base URLhttps://redrouter.org/v1
Model IDstep-5-preview
curl 'https://redrouter.org/v1/chat/completions' \
  -H "Authorization: Bearer $REDROUTER_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"messages":[{"content":"Hello","role":"user"}],"model":"step-5-preview"}'

Set REDROUTER_API_KEY to a key from API Keys.

Supported parameters

modelmessagesstreamstream_optionsmax_tokensmax_completion_tokenstemperaturetop_pstoppresence_penaltyfrequency_penaltyseedtoolstool_choiceparallel_tool_callsresponse_formatuserreasoning_effortreasoningenable_thinkingthinkingthinking_budgetchat_template_kwargsoutput_config

Other parameters return HTTP 400; user is accepted but not forwarded. Request fields and limits.