StepFun AI

Connection

Field	Value
Anvia SDK	@anvia/openai
Compatibility	OpenAI-compatible endpoint
API URL	https://api.stepfun.ai/step_plan/v1
Environment	STEPFUN_API_KEY
Provider docs	https://platform.stepfun.ai/docs/en/step-plan/integrations/open-code
Models	2

Anvia Usage

This provider is listed as OpenAI-compatible. Start with @anvia/openai and the chat-completions adapter, then smoke test the exact workflow.

import { OpenAIClient } from "@anvia/openai";

const client = new OpenAIClient({
  apiKey: process.env.STEPFUN_API_KEY,
  baseUrl: "https://api.stepfun.ai/step_plan/v1",
  completionApi: "chat",
});

const model = client.completionModel("step-3.5-flash");

Capabilities

Capability	Value
Input modalities	text
Output modalities	text
Attachments	0 / 2 models
Tools	2 / 2 models
Structured output	0 / 2 models
Reasoning	2 / 2 models
Temperature	2 / 2 models
Open weights	2 / 2 models

Models

Model	Family	Input	Output	Capabilities	Limits	Cost	Updated
step-3.5-flash Step 3.5 Flash	-	text	text	tools, reasoning, temperature, open weights	context: 256000 / input: 256000 / output: 256000	input: 0.1 / output: 0.3 / cache_read: 0.02	2026-06-15
step-3.5-flash-2603 Step 3.5 Flash 2603	-	text	text	tools, reasoning, temperature, open weights	context: 256000 / input: 256000 / output: 256000	input: 0.1 / output: 0.3 / cache_read: 0.02	2026-04-02

Read Gateway caveats before enabling this provider in production.