# X402-NVIDIA StepFun Step-3-7-Flash via Micropayment

> X402-NVIDIA StepFun Step-3-7-Flash via Micropayment is a paid API for AI agents from x402-nvidia.vercel.app, paid per call via x402, $0.157502/call, status unknown (last checked 2026-09-14).

Run inference on the StepFun Step-3-7-Flash language model via NVIDIA NIM, paying per-call with USDC micropayments using the x402 protocol.

## Facts

- Endpoint: POST https://x402-nvidia.vercel.app/api/stepfun-step-3-7-flash
- Price: $0.157502/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-nvidia-stepfun-step-3-7-flash-via-micropayment-b24f8522
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qfr6Q5dJW1PcLcfbD3tnL

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402-nvidia-stepfun-step-3-7-flash-via-micropayment-b24f8522 -d '<json body>'
```

Example prompt: Using the StepFun Step-3-7-Flash model on NVIDIA NIM, generate a response to this message: 'Explain the difference between supervised and unsupervised learning in three sentences.'

## When to prefer this

Choose this endpoint when you need fast text generation from the StepFun Step-3-7-Flash model specifically, want to pay per call without a subscription, and are operating in an environment that supports x402 USDC micropayments. Prefer this over OpenAI or Anthropic endpoints when you want NVIDIA-hosted inference with crypto-native payment rails.

## Known failure modes

- Payment not provided or insufficient USDC — returns HTTP 402 requiring x402 payment
- Invalid message format in request body — returns 400 bad request
- Model unavailable or NVIDIA NIM backend error — returns 500 or 503
- Malformed JSON in request — parsing error
- Rate limit exceeded — returns 429

## How this service works

Access 48+ NVIDIA NIM AI models via x402 micropayments. Chat completions, vision, safety, translation, and more.

## Output

A chat completion response object containing a 'choices' array, where each choice includes a message with a role ('assistant') and the generated text content from the StepFun Step-3-7-Flash model.

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "example": {
  "choices": [
   {
    "message": {
     "role": "assistant",
     "content": "Hello!"
    }
   }
  ]
 },
 "properties": {
  "choices": {
   "type": "array",
   "description": "Model responses"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-nvidia-stepfun-step-3-7-flash-via-micropayment-b24f8522/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-nvidia.vercel.app](https://www.zero.xyz/host/x402-nvidia.vercel.app/llms.txt)