Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token. It is a reasoning model that is very speed efficient even at long contexts.
$0.05
$0.05
$0.15
Throughput is how fast the model writes (tokens per second, higher is better). Time to first token is how long before the answer starts (lower is better).
Share of requests served without a server error. Client errors (4xx) do not count.
Works with the OpenAI SDK pointed at our base URL. Every parameter is in the API reference.
Tokens processed per day on NagaAI.
Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token. It is a reasoning model that is very speed efficient even at long contexts.
On NagaAI, Step 3.5 Flash costs $0.05 per 1M input tokens and $0.15 per 1M output tokens. You pay only for what you use, with no subscription.
Step 3.5 Flash reads up to 262.1k tokens in one request, counting the prompt and the answer together.
Step 3.5 Flash can call your functions as tools. Answers in a JSON schema are not available for it.
It takes text as input and returns text.
Create an API key, copy the model ID from the top of this page and send requests with the OpenAI or Anthropic SDK pointed at NagaAI. The API section on this page has a ready example.
Not enough throughput data
Not enough TTFT data
Not enough activity data to display a chart
