# GPT-4o Mini via x402 Gateway

> GPT-4o Mini via x402 Gateway is a paid API for AI agents from x402-gateway-production.up.railway.app, paid per call via x402, $0.003000/call, status unknown (last checked 2026-09-15).

Calls OpenAI's GPT-4o Mini model for fast, affordable text generation suited to simple tasks and high-volume agent use

## Facts

- Endpoint: POST https://x402-gateway-production.up.railway.app/api/llm/gpt-4o-mini
- Price: $0.003000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-gateway-production-up-railway-app-05883914
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_drG6upix1snyb_oofVoXT

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-gateway-production-up-railway-app-05883914 -d '<json body>'
```

Example prompt: Use the affordable GPT-4o mini model to summarize this customer feedback in one sentence: 'The onboarding was confusing but the product itself is excellent once you figure it out.'

## When to prefer this

Choose this endpoint when you need fast, low-cost LLM completions for simple tasks, bulk processing, or high-frequency agent loops where GPT-4o or more powerful models would be overkill. Ideal for classification, summarization, short Q&A, and any use case where cost-per-call matters. Prefer over heavier models when latency and cost are priorities over maximum capability.

## Known failure modes

- Payment not included or insufficient USDC — returns 402 Payment Required
- Malformed request body — returns 400 Bad Request
- Model overloaded or upstream OpenAI error — returns 503 Service Unavailable
- Prompt exceeds token limit — returns 400 with token limit error
- Invalid API key or auth failure — returns 401 Unauthorized

## How this service works

Fast, affordable GPT-4o variant — great for simple tasks and high-volume use

## Output

Returns a generated text completion from GPT-4o Mini — the model's response to the provided prompt or message thread, suitable for tasks like summarization, classification, Q&A, and content drafting.

## Example request

```json
{
 "messages": [
  {
   "role": "user",
   "content": "Summarize this customer feedback in one sentence: 'The onboarding was confusing but the product itself is excellent once you figure it out.'"
  }
 ]
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-gateway-production-up-railway-app-05883914/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-gateway-production.up.railway.app](https://www.zero.xyz/host/x402-gateway-production.up.railway.app/llms.txt)