# Gambit Nemotron Chat — x402 USDC on Base

> Gambit Nemotron Chat — x402 USDC on Base is a paid API for AI agents from gambit.barrioenergy.com, paid per call via x402, $0.08/call, status unknown (last checked 2026-09-14).

Send a chat message to NVIDIA's Nemotron-3-Super 120B model via Gambit's GPU shop, paying $0.08 USDC per call using the x402 protocol on Base.

## Facts

- Endpoint: POST https://gambit.barrioenergy.com/x402/chat/nemotron
- Price: $0.08/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gambit-nemotron-chat-x402-usdc-on-base-60cd0934
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hBeHoRhvRaFMDw_nRRnWs

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 gambit-nemotron-chat-x402-usdc-on-base-60cd0934 -d '<json body>'
```

Example prompt: Ask the Nemotron 120B model on Gambit: 'Explain the difference between transformer and Mamba architectures in 3 paragraphs' — limit the response to 800 tokens.

## When to prefer this

Choose this endpoint when you need inference from NVIDIA's Nemotron-3-Super 120B model specifically, want to pay per-request in USDC on Base without a subscription, are building a crypto-native or x402-compatible agent pipeline, or need a powerful open-weight model accessible via Web3 payment rails rather than a centralized API key subscription.

## Known failure modes

- Insufficient USDC balance causes 402 Payment Required with payment instructions
- Malformed messages array (missing required 'role' or 'content' fields) returns 400 Bad Request
- max_tokens value too large for context window returns error
- Model overloaded or GPU unavailable returns 503 Service Unavailable
- Invalid x402 payment header or wrong chain causes payment rejection
- Empty messages array may return empty or error response

## How this service works

Gambit GPU shop. Humans: /signup ($1 credit), X-API-Key on /v1/*, QR Lightning top-up. Bots: L402 Lightning (LIVE) on /l402/*, x402 USDC on Base on /x402/*, or POST /v1/register ($0) then POST /v1/topup/lightning. Handwritten letter POST /x402/letter at $25.00 USDC. Funnel https://gambit.barrioenergy.com. Free probe GET|POST /x402/models.

## Output

Returns a JSON object with the model name ('nemotron-3-super:120b-a12b') and an assistant message object containing the role ('assistant') and generated text content.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "type": "string"
     },
     "content": {
      "type": "string"
     }
    }
   }
  },
  "max_tokens": {
   "type": "integer",
   "default": 512
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "model": "nemotron-3-super:120b-a12b",
  "message": {
   "role": "assistant",
   "content": "Hi."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gambit-nemotron-chat-x402-usdc-on-base-60cd0934/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gambit.barrioenergy.com](https://www.zero.xyz/host/gambit.barrioenergy.com/llms.txt)