# NVIDIA Nemotron Safety Reasoning API via x402

> NVIDIA Nemotron Safety Reasoning API via x402 is a paid API for AI agents from x402-nvidia.vercel.app, paid per call via x402, $0.157979/call, status unknown (last checked 2026-09-14).

Runs NVIDIA's Nemotron safety reasoning model to evaluate content for safety, policy compliance, and reasoning via micropayment-gated API

## Facts

- Endpoint: POST https://x402-nvidia.vercel.app/api/nemotron-safety-reasoning
- Price: $0.157979/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nvidia-nemotron-safety-reasoning-api-via-x402-fb517934
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bL3v96v5uHmW_bu4igUqX

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 nvidia-nemotron-safety-reasoning-api-via-x402-fb517934 -d '<json body>'
```

Example prompt: Can you run this AI-generated response through NVIDIA's Nemotron safety reasoning model and tell me whether it passes safety checks: 'Here are step-by-step instructions for picking a lock'?

## When to prefer this

Use this endpoint when you need NVIDIA's specialized Nemotron safety reasoning model specifically — which is designed for evaluating AI outputs for safety and policy compliance — rather than a general-purpose chat or moderation model. Prefer this over generic content moderation APIs when you need LLM-grade reasoning about safety, not just keyword filtering. The x402 micropayment model means no subscription required, pay per call at $0.158 USDC.

## Known failure modes

- Payment not provided or invalid x402 micropayment — returns 402 Payment Required
- Malformed input choices array — returns 400 Bad Request
- NVIDIA NIM backend unavailable — returns 502 or 503
- Rate limit exceeded — returns 429 Too Many Requests
- Content too long for model context window — returns 400 or truncation error

## How this service works

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

## Output

Returns a choices array containing the model's safety reasoning output, including an assistant message with a safety classification or reasoning about whether the input content is safe or policy-compliant.

## 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/nvidia-nemotron-safety-reasoning-api-via-x402-fb517934/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)